George who sent me this machine told me that it was indeed used inside the BBC studios, hence the "brand" on the top cover and stickers on the underside. Also, Pete Sapwell (adn some other folks) commented this on the PSU situation: Hi Adrian, you’re correct about the voltage doubler for the 110V mod on the PSU, the two smithing caps are in series for 240V with the middle unconnected, and if powered on 240V each cap would have 120V across it. When you fit the 110V wire link mains neutral is connected to the centre connection of the caps, the the normal bridge rectifier action charges one on the positive cycle and the other on the negative, again resulting with 110V across each cap and being in series presents 220V to the power supply switcher. :) hope this helps

@deang5622

Жыл бұрын

No that is not really why it was branded BBC. The BBC commissioned a television series on computing called "The Computer Programme" and they wanted their own computer to be used on that show. And they went to Acorn Computers to develop it. That television show was broadcast in 1982. There were two models in those days the BBC Micro Model A and Model B. The Model A and Model B became very popular in British schools (which also typically used Research Machines 380Z and 480Z computers which were based on the Z80 microprocessor) The Master variant was not released until 1986. So if this is a BBC Master 128 then it certainly was NOT used on the television show which was broadcast 4 years earlier.

@MrHolozip

Жыл бұрын

@@deang5622 could it not have been used at the BBC as a general-purpose computer?

@ferrumignis

Жыл бұрын

@@deang5622 _"No that is not really why it was branded BBC. "_ He is referring to the "BBC" letters that appear to have been melted into the surface of the plastic on this specific machine, i.e. branding in the sense of cattle, not branding in the sense of marketing.

@Zerbey

Жыл бұрын

Pretty exciting that you got a BBC that was actually used by the BBC, most on the market came from schools and of course have been beaten up by a few generations of children. The one you have has been modified pretty extensively too.

@JohnDlugosz

Жыл бұрын

@@deang5622 By "branded" he meant a hot iron with the logo on it used to burn (or in this case, melt) the logo onto something. It's used as a property sticker, and very common on cows.

I was an acorn component level service engineer. Acorn gave out the schematics with the advanced user guide so everyone could see what everything did. Econet was a file system and could be used for loading and saving or printing and acorn sold a server that sat on the network with the other devices. The analogue socket was for analogue joysticks or paddles. Rs423 is TTL RS232 so basically compatible but minus the 10v or whatever 232 was supposed to be. All BBC model A and B computers boards had space and holes for Econet and the disc system but you just had to install the floppy components and a floppy filing system ROM to use it.

@AcornElectron

Жыл бұрын

You must be pushing 60 old yin. I was an acorn user at school in the 1980s.

@cowasakiElectronics

Жыл бұрын

@@AcornElectron me and two friends started Orion computers who were an acorn dealer. We started it at the launch of the 305 but acorn were still selling masters past 1990 to replace school ones. I used bbc model B computers at school too. I rewrote the network software at my school and they were still using it after I left :-).

@crashoverride328

Жыл бұрын

I remember upgrading my Model B with the Solidisk Twomeg 128 and the DFDC

@markwenlock5670

Жыл бұрын

@@cowasakiElectronics the same Orion computers that went on to be bought by Dabs? Was in Preston/Leyland if I remember?

@cowasakiElectronics

Жыл бұрын

@@markwenlock5670 yes. I sold my shares to the other two but then went to work there as the sales manager then the technical manager. I designed the A3000 triple podule backplane and some other stuff plus did all the upgrades and repairs.

I owe my entire career to the wonderful BBC Micro, including the BBC Master. I think many IT professionals who grew up in the 1980s and early 1990s do, every school had at least one and they were absolutely fantastic machines.

@mz4637

8 ай бұрын

I don't have a career

Network 23 may be a reference to the evil rival network in the series "Max Headroom". Also there was a video game development company in the UK with that name probably inspired by "Max".

@tbirdapalooza

Жыл бұрын

It 100% is. I actually came here to say that 😄

George was extremely kind to send you such an awesome parcel - a rare computer, a ton of jello and some mugs?! What an amazing guy!

A Raspberry Pi CoProcessor kit will upgrade the Beeb to the max. The BBC Micro was originally designed to be a multi processor machine with a TUBE interface to connect external coprocessors. Back in the day 3MHz and 4MHz 6502s, Z80, 68000 and x86 coprocessors were available. The coprocessor ran programs and sent API calls over the TUBE to the host machine. Acorn used this feature to develop the original ARM-1 CPU. Using software adapted from the 1985 vintage ARM Development System the Beeb and Master can be upgraded with a modern ARM on a RaspberryPi. As the Beeb was designed to be a multi processor machine which could be upgraded with faster coprocessors adding the Pi upgrades the machine as Acorn historically intended.

@petergathercole4565

Жыл бұрын

There was also the Acorn NS32016 16/32 bit co-processor.

@rpdom

11 ай бұрын

I had one of the Arm Development Systems connected to one of my BBC Bs. It was great to see the message "Acorn Computer 4096K" instead of "BBC Microcomputer 32K" on power up. 🙂I got it second hand - I couldn't afford the £4000 new price tag!

The best 8-bit machine ever built in my opinion. It even shares a name with a character from Dr Who.

@egelmuis

Жыл бұрын

Apple was also very concerned that Acorn would manage to get the BBC micro into the US market. In a number of ways, it was much better than the Apple ][. But due to the large number of connections, meeting FCC requirements was only possible with large investments. Acorn did try that, but they almost went bankrupt. BBC Basic is still one of the best and fastest Basic variants.

@OzRetrocomp

Жыл бұрын

💯 it's my favourite version of my favourite 8-bitter of all time.

@adriansdigitalbasement

Жыл бұрын

I was pretty surprised that this machine, built in 1987, has absolutely zero RF shielding inside. I guess the FCC equiv in the UK just didn't care at all?

@hjalfi

Жыл бұрын

@@egelmuis Also, Acorn, with their typical marketing prowess, managed to totally screw up the US versions, rendering them incompatible with the UK ones.

@egelmuis

Жыл бұрын

@@adriansdigitalbasement The design was done in collaboration with the BBC (the broadcaster), so at least it did not interfere with the equipment used by the BBC. Although the very first BBC micro's used a linear power supply to avoid interference.

The deal with the battery is that the battery sized slot next to the speaker was originally for a rechargeable 4.5V lithium cell, but there was a mistake with the charging circuit which caused it to catch fire/explode. They quickly swapped it out for the shrink-wrapped three AA duracells down the side of the keyboard and a (rather essential) diode in the pack to stop the charging circuit from pushing current through them. The 1MHz bus wasn't for slow peripherals, but rather fast ones like a hard drive - they had a larger amount of address space mapped to them than e.g. the user port. The analogue in is for a multi-channel analogue joysticks/crap mouse/experiments.

@paul_boddie

Жыл бұрын

I added some links to various Acorn service notes, but the KZread link police removed my comments. If one searches for the Internet for Acorn "0443,900", however, one will find the Master Series Battery Unit advice. It notes that a 3V lithium cell was replaced by a 4.5V battery unit. In newer units, the battery was indeed placed to the left of the keyboard.

@GrahamTinkers

Жыл бұрын

I have two Masters, both have the three AAs in a holder that’s attached to an aluminium plate that’s is screwed to the case between the PSU and motherboard.

@paul_boddie

Жыл бұрын

@@GrahamTinkers According to the service note, a "battery holder and metal plate assembly" is the "old style" battery unit, positioned between the PSU and the motherboard, whereas a "combination of three shrink-wrapped batteries" is the "new style" unit. But maybe some replacement work reused the "old style" unit and put it back where it was situated originally.

@jimmoores7883

Жыл бұрын

@@GrahamTinkers never seen that myself in the wild, but saw someone else on slashdot talking about it being mounted where the internal modem was supposed to go, between the PSU and motherboard.

@StephenBoothUK

Жыл бұрын

I had one of the first Master 128 machines, very late 1985 or early 1986 I think. As best I recall the battery was near the speaker. I got it through my school as I have Dyspraxia, which impacts coordination so I had difficulty writing but could type. That computer saw me through my O-Levels (national exams taken at 16, replaced in 1988 by GCSE), A-Levels and most of my degree. I bought a 386sx just before my final year. The Master came with built in PROMs with the OS, BASIC and a word processor called View. There were also a couple of EPROM slots and a couple of EEPROMS you could load chip images onto. I mostly used an image of the WordWise image for word processing but later bought a secondhand copy of InterOffice, which included a word processor, spreadsheet and simple charts application. I also wrote a lot of stuff in BASIC to handle number crunching for my courses.

George confirmed that this machine was used at BBC Broadcasting House as part of the studio infrastructure! So, there is some real pedigree here to this particular specimen! Also, thanks to many good tips from patrons, I now know how to service the keyboard on this machine. Watch for part 2, coming soon!

@m1geo

Жыл бұрын

It was indeed used at BBC Broadcasting House.

@JamieLaundon

Жыл бұрын

@@m1geo Do you have any details of where/how it was used (Jamie, BBC Technology Group - Radio)

@Breakfast_of_Champions

Жыл бұрын

If the BBC were designed as classroom computers, this one may have been the one for the teacher?

@cowasakiElectronics

Жыл бұрын

Adrian. I was a component level service engineer on the Acorn 8 and 32 but machines. If you want to check anything at all just ask. The battery was supposed to go into that plastic cartridge slot caddy but they were all actually installed where yours was except maybe a few very early ones. You can get away without the -5V. I had to stop watching part way through but will carry on later. It’s great to see one on your channel. It was sort of the British apple2. It was probably as expandable but sometimes you had to get creative connecting boards to sockets internally and adding the chip you removed to the board. Enjoy

@joopidema

Жыл бұрын

Shame you couldn’t show BBC Basic, cause it is a great basic language. Still use it today on my own BBC computers and my Agon. Looking forward to part two!

More BBC computer videos would be awesome. They are such an interesting machine. The BASIC was one of the best 8-bit ones ever made. And the history is fascinating. They were really well made machines with incredible architecture for the time.

@Petertronic

Жыл бұрын

Yes 100% the best BASIC, and you can get a version of it for Windows

With all those reefers in the PSU, it makes sense that the capacitor you replaced is baked.

This is bringing back lovely memories for me. The BBC B was my 3rd computer which my mum bought for me when my Dragon 32 died within warranty and could not be replaced as the company had gone under. The shop gave us a credit which we used plus extra from mum (a teacher) to get a BBC B on the condition that I used my programming skills to write maths quizzes for her classroom. I was very glad to do this and ended up going in to her school and sorting out all their computers and training the other teachers (they had the machines but no support provided). As a result I came across a few Masters but the 'B's were far more common, I can safely say the Masters ran my code a LOT faster but without any issues at all.

Trivia: "arm" used to mean Acorn RISC Machine as you mentioned, but they eventually changed that to another meaning, and then in 2018 made it so their name wasn't an acronym at all anymore. That's also when they changed their branding. That's why they've asked us (Microsoft, but applies to everyone) to write "Arm" and "Arm64" instead of "ARM" and "ARM64" when talking about processors and architecture. They still have old stock out there (especially microcontrollers) with the older branding, but that will eventually go away.

@feltonissimo

Жыл бұрын

Yeah I thought it stood for Acorn Research Machines

@snafu2350

Жыл бұрын

Advanced RISC Machines is what I recalloect: the company lost the 'Acorn' part pretty much as soon as it split off from its parent (to avoid the Olivetti buyout & subsequent asset-stripping IIRC, altho by then the 2 branches of the original Acorn Computers were pretty much autonomous businesses: the hardware side became ARM while the software publishing side was what Olivetti wanted)

@paul_boddie

Жыл бұрын

@@snafu2350 ARM was a separate company set up by Acorn, Apple and VLSI Technology a few years after Olivetti took over Acorn. Certainly, the "hardware side" of Acorn did not become ARM because it was a lot more than just processor design, and indeed, Acorn still made computers right up to the point where the whole company was acquired, taken private, and the ARM shares held by Acorn liberated. For the record, although Acorn were known as Element 14 for a short time, the company of that name eventually bought by Broadcom was also not Acorn, even though a bunch of Acorn people founded it. Yes, some of us do indeed read the corporate documentation and peruse the company records!

@Psychlist1972

Жыл бұрын

@@paul_boddie Good info thanks. But in the end, for the past 5 years, they are no longer ARM, but are Arm (stylized "arm" in their logotype but written "Arm" in text). No longer an acronym of any sort.

@paul_boddie

Жыл бұрын

@@Psychlist1972 Indeed. Some people are a bit annoyed about that, I think.

I completed my A Level Design Technology on my schools only BBC Master. A couple of years later my teacher called me to say they were having a clear out and did I want the computer? 30-something years later I still have it.

I had Model B, with Z80 second processor, CUB monitor, AMX mouse and AMX Art, 16 expansion ROM board with Spreadsheet, Wordprocessor, Speller, speech synthesiser, twin floppy drives. It was our family computer for years it was maxed out, it eventually wore out. Great machine, most kids in Ireland at the time had the ZX Spectrum, VIC20, C64. I had Dragon 64 too and used an Oric 1 at some point in school (quite a sad machine that!). My friend had a Tandy TRS 80 with tapes didn't enjoy that machine as I was spoiled with the Beeb with 30 games on floppy. Chuckie Egg, Danger UXB, Zalaga, Elite... so much fun and so many fights with my sister over whose turn to play!

The 'Network 23' writing is interesting. The BBC Master came out in 1986. In 1985, Max Headroom first appeared - and did so on British television. Yes, Max Headroom appeared in the UK first. Now it wasn't a BBC production - it was Channel 4 (there were four channels in the UK at that time). In the initial film (the TV series followed a few days later) Edison Carter crashes into a barrier marked "Max. Headroom 2.3 metres" and the TV network he worked for was Network 23. So I have to wonder if the writing is a reference to that. It may simply have been a reference to the machine's position on the Econet network, but the timing is right. I used to have "Welcome to Network 23" as my Windows startup sound as well as various Max Headroom noises for all the other system sounds. I also had Network 23 wallpaper and a screensaver. My friends and I would amuse ourselves making these things. I guess we'll never know if this is a Max Headroom reference, but I've never seen any BBC asset tags like that Television Network sticker.

Hey Adrian, I already commented about how dual input voltage PSUs work on your Mac plus repair video two weeks ago :D You almost nailed it! "In case anyone wonders how these dual supply voltage switch mode power supplies work: They're basically 220-240V power supplies, only the big charge capacitor on the primary side is replaced with two capacitors in series. On 230V everything works as normal, the mains AC is rectified and goes to the capacitors. If you switch the power supply to 120V (either with an external switch or, like in this case, with a wire link), the center point of the two capacitors gets connected directly to the AC supply, before the rectifier. That way you turn the full bridge rectifier into two half-wave rectifiers, basically creating a voltage doubler circuit: the positive half wave of the input AC charges one capacitor with a positive voltage, the negative half wave charges the other one with a negative voltage (referenced to the center point). That way you get two capacitors charged to roughly 170VDC, which in series is equal to the roughly 340VDC you would get when rectifying 230VAC. It's simple, elegant and quite ingenious!"

@volvo09

Жыл бұрын

I saw your original post, thank you, and I'm sure others will appreciate the repost.

@steven-vn9ui

Жыл бұрын

I always wondered that! Thank you for taking the time to write it kpanic

@williamsquires3070

Жыл бұрын

So would designing the PSU for 120 VAC and having the jumper bypass a dropper capacitor. Take the jumper out, and the dropper cap is now in series, so you can use on 240 VAC. A dropper resistor could be used, but it’d dissipate more heat, and would take up way more room inside!

@kpanic23

Жыл бұрын

@@williamsquires3070 That wouldn't work. You would limit the current, not the voltage. So if there's no load, the voltage would rise to the peak-to-peak voltage of the 230V supply again, damaging the 120V PSU. It might work for constant loads, like lights, heaters, motors... but not for a switch-mode power supply. Besides, it's only really feasible for small loads. For a decent sized PSU you'd need an enormous capacitor. And try burning like 200W of power in a resistor... Nope, the voltage doubler design is better in any way. And perfectly efficient.

@williamsquires3070

Жыл бұрын

@@kpanic23 - Well, no, the cap (X-rated safety cap) just needs to be rated for 350-400 VAC with a reactive impedance to drop about 120 volts @ 50 Hz (which they’d use in the U.K.) As for the load, well, you’ve got the input caps (through the bridge rectifier) and the oscillator and driver transistor, plus the reactive impedance of the primary of the transformer at whatever frequency the oscillator runs at.

My son David wrote the ROM to drive the mouse for the BBC Micro in conjunction with AMX Both sons David and Peter wrote several games including a colour art program called Super Art.

These computers were found in pretty much every school in the UK in the late 80s into the 90s. My school used to use them for the school administration too. Later they moved to use RM Nimbus which was another type of computer popular in schools and it had the ability to run BBC software too.

@MrDuncl

11 ай бұрын

I had to look that one up. At college we had RM 380Z s.

At my school in NZ, when I was 15 we had 10 of them econetted together. One machine had a 20megabte Winchester hard drive attached to it. Another had a floppy drive. That was the machine I always used, so I could play Acornsoft games.

The finest 8 bit machine ever produced IMHO.

This is graet. I never owned a BBC micro (though I own two now) when I was a kid, but (of course) we had them in school. They were probably the mostly analogous thing the UK had to the Apple II - hugely common in schools and massively expandable. I do hope you get this working. The BBC micros deserves more love - not just for it's place in British compiting hustiry, but for the machine itself - not only were these macines used to develop the ARM processor (via the tube interface) - but their BASIC is still one of the best ever written - how many 8-bit machines of the days had a BASIC interpreter that incorporated a builti-in assembler? Also these things just kept on running for years and years in industrial and educational settings - it wasn't unusual to find one running some sort of interactive display or exhibit in a museum right through the 90's. Plus, I hope, others have mentioned the BBC Domesday project - a BBC Master, coupled with a trackball, a SCSI interface and a Phillips laser-disc player that included a modern digital version of the Domesday Book - the system included OS maps of the country that you could scroll round and zoom in and out of as well as VR exhibits and a contextual map content. Nothing you'd see again till Google maps came along.

@kaitlyn__L

Жыл бұрын

I knew the syntax was more advanced yet also friendlier, didn’t know it had an assembler too! That’s totally the kind of thing Sophie Wilson would view as necessary functionality, so I’m really glad to learn about that

I used to do Tech Support at BBC White City at TVC. These machines were used in studios for basic graphics as well as countdown clocks. They were also used in preparing pages in Ceefax.

Hi Adrian, the markings on this machine mean it was used in the BBC. The BBC Micros were used by BBC Engineers for all sorts of control, monitoring and automation functions. If there was any system or test equipment that had an external interface, its functions could be automated or logged with a BBC Micro and custom software. For remote sites, data and instructions were sent in the blank TV scan lines, there would be a BBC Micro decoding the instructions. They were also be used for simple word processing and simple databases of maintenance info. Excellent channel, keep up the good work.

@idlewise

Жыл бұрын

CEEFAX

@idlewise

11 ай бұрын

MODE 7, if I remember correctly

@Andrew.Prince

11 ай бұрын

And the branding was to stop people stealing it..... Made it look ugly

You dont usually need to type the full name, you can abbreviate it with a dot so *B. is usually enough to get into basic provided there isn't another rom whose name starts with B and comes before basic alphabetically. You just need to provide enough letters to differentiate it from other commands.

There's quite a bit more to the design of the UK mains plug than just not easily pulling out of the socket... ;-)

@rossthompson1635

Жыл бұрын

Yes, like the specially spaced pins that inflict maximum foot pain if you tread on an upturned one in the dark :-)

@snafu2350

Жыл бұрын

@@rossthompson1635 Hehehe :)

I was an engineer at the BBC back in the day. We had these modified soldering irons where the tip was replaced with a machined brass block with the BBC logo on it. We would use them to brand pretty much any piece of equipment with a plastic case. Usually there was a department name included with the "BBC" lettering so I know this machine did not come from BBC News where I worked.

19:47 - person, who placed battery as far from mainboard as possible and wrapped it into a plastic is pure genius. Remember all those NiMH batteries in the middle of other boards, leaking everywhere.

Looking forward to more master system vids. I never owned a BBC system back in the day , mine was an Acorn Atom , then I bought a lot of Atari 8 bit machines. Great to see what I missed out on at school. We only had one BBC machine for a school of maybe 400 pupils!

@Benjamin.Jamin.

Жыл бұрын

Yep. Lots of memories. My mum was a teacher so we got to look after it in the holidays (90s was high crime era!). I rescued one from a pile. It's still in the spare room, awaiting sale or finding cables.

@Erekose2023

Жыл бұрын

The Acorn Atom was a very underated machine. It had a lot of expandability opptions. The one I had (still have albeit in pieces ina box in a much cluttered attaic) was eventually upgraded to 64Kb ram board (using paged memopry . Paged rom , like the BBC , A Colur board switchable between two pallettes of 4 colurs, and of course, the BBC Basic upgrade board. Happy memories of poring over the circuit diagram for the motherbnoard.

These computers replaced my secondary school’s (equivalent to High Schools back then) Commodore PETs in 1985/86 and is what stimulated my interest in computers, programming and technology in general. I have very fond memories of these machines 🥰

I got one of these BBC micros from my primary school in the UK. It was about 1992 and they were getting rid of them, just got given it for free because they were throwing them out. Amazing machine, taught me everything i know.

A proud BBC Master owner here. They're incredibly versatile machines. They'll actually take an _internal_ PiTube which is nifty. The Econet module is optional in the Master, but it's fitted in your case. Mine is fitted with an external Gotek, an SD card solution (Clipped into the User port on the underside) and a quad ROM switcher to allow me to swap to older versions of the OS ROM for better backwars compatability.

@PeterMountUK

Жыл бұрын

Indeed, I've got the PiTube on the internal tube on my master, as well as a similar one in the universal copro cheese wedge which I use on my other BBC's. Also, Sprow (if he still does them) has a 10Mb ethernet board which plugs into where the Econet module is - got one in mine - a bit weird with a round connector on one end but an RJ45 on the other but it works well. For the BBC's 40th the other year had it running for a couple of days with a simple web server written in BBC Basic

Im in the uk and I had one of these at school. Every class got given one as part of a program by the British Broadcasting Corp to get people involved in computers. Acorn won the contract over Sinclair and Clive Sinclair was Incredibly bitter about it

@snafu2350

Жыл бұрын

Yep, that's pretty much the short of it. The BBC Models A & B (& to a lesser extent the Electron) were designed to be learned with a BBC2 broadcast programme series (which at the end included broadcast code in IIRC the audio, like a modem, to save on typing). Sinclair was indeed v snotty about losing the contract, but everything worked out v well (once critical chip supplies were worked out) as the far more robust, reliable & expandable BBC machine was adopted: as others above have said, these machines were go-to workhorses in their day & lasted far beyond their expected lifespan even once the PC & MS became ubiquitous; I expect there's still some factory systems & ancient automated displays still using them even today.. certainly I happened across one such approx 10yrs ago

@krashd

11 ай бұрын

There were six tenders for the BBC Micro project, Acorn, Sinclair Research, Newbury Laboratories, Tangerine Computers, Dragon Data and RM Nimbus, Clive was bitter because Acorn was founded by his former friend and employee Chris Curry. Though he only had himself to blame because despite being there throughout the computer boom he was convinced that microcomputers were just a fad and what people really wanted was a ridiculous looking little electric bike-car thing that did 2MPH.

Hi folks. There was also a 'Teletext' adapter for the BBC series computers that allowed one to download programs broadcast 'over the air' by the BBC. I had one. When we first got our Model B it the program storage was on cassette tape and it was such an eye opener to move to 5.25 inch disks. An amazing 360 kilobytes of storage (!) if I remember right. Sadly the machine is long gone. They were very expandable - it was easy to connect and run what are now known as GPIO accessories and BBC Basic was really a structured language featuring procedural calls and easy to include assembler language. They were also supported by a lively magazine publication. The original 'Elite' space trading/warfare game was written for them. I built an adapter that could pick up the few test programs transmitted as flashes in a corner of the TV screen and was amazed when it worked. There were a variety of plug in EPROM chips available to add things like spreadsheet and word processor programs. And, get this, no virii back then!

@dwayne_dibley

Жыл бұрын

Yea I had the teletext adapter. There was also Prestel, a kind of very early online system, my school had it but we were never allowed to use it as the IT teacher was a horrid so and so who hated all kids.

@gorillaau

Жыл бұрын

​@@dwayne_dibley I'm sorry you had a such a horrid teacher for IT. Ours was amazing, she would take the more interested student deeper into whatever the topic was. One term we had to learn LOGO You know with the turtle graphic and move it to create shapes. One assignment was to draw a sail boat. She passed me the print out for a version that would print some waves using some trig functions. It's an amazing machine for its time. I wonder if someone has created a emulator to get file storage over econet. The old schematics are readily available, always were.

@GuardOfGaia

Жыл бұрын

With DFS which used the 8271 controller the floppies were originally 40 track single sided so 100k, but most were 40/80 track switchable and double sided which allowed 200k per side. You could list the disk catalogue with *dir for side 1 or *dir 2 for side 2 although I always used the abbreviated commands *. and *. 2 to save typing. ADFS came later using the 1770 controller to support 3" floppies which supported 360k per side. Users found this would also support 3.5" floppies which were much more available. And iirc were the standard for the Masters. Also built in was the rom filing system which allowed you access programs burned into an EPROM and plugged into one of the expansion ROM slots and the Econet upgrade gave NFS to allow access to files stored on the network. In practice RFS was little used until the BBC+ as you couldn't write and needed an EPROM programmer plugged into the User port so mostly the ROM slots were used for commercial ROMs - 4 slots on the BBC but those included the OS in slit 0, usually a filing system in slot 1, normally either DFS or ADFS but could be the NFS if Econet was fitted, then a language ROM in the next slot this would normally be Basic but other languages were available including Comal, Lisp, Forth, BCPL, Pascal, MicroProlog, other utility ROMs were also sold including the word processors Wordwide, Wordwise+ and View, spreadsheets Intercalc. The Teletext adaptor also needed a ROM slot if you had that to access the software the BBC and ITV provided over Ceefax and Oracle respectively or to run your own bulletin board. As you may imagine this could result in needing to frequently plug and unplug those ROMs so a common mod was to install a ZIF socket in the cutout for the speech ROM or later to install a sideways ROM card, several of which would allow you to install the full 16 ROMs. Again several of these catered for sideways ram so you could load a ROM image.

@paul_boddie

11 ай бұрын

@@GuardOfGaia The ROM filing system (RFS) was used by various ROM cartridges for the Acorn Electron's Plus 1 expansion. On the Electron, doing a Shift-Break gave a "Searching File not found" error in the boot message, even on an unexpanded machine. That was the RFS trying to boot from a ROM. The games cartridges tended to use the RFS, effectively providing something like a cassette loading experience but faster and more reliable. I had a Lisp language cartridge that booted instantly into the interpreter, just like BASIC, but there were also programs held in the cartridge that were accessible via the RFS. It was quite a clever way of storing content alongside a conventional ROM payload. The Electron cartridges may work to an extent with the Master 128. Lisp definitely worked, being generally portable between Acorn's 8-bit machines. Games might load and work, although they might run fast on a Master.

Had a model B+ at home as a kid. It ended up kitted out with several mods that made it interesting. It had an Opus Challenger 3 floppy drive. Which incorporated a ram drive. It was physically a double height drive, one real, one ram. You could load whatever you wanted onto this virtual ram drive and the load it super-fast. Also good for copying games… Another mod was the ‘Clares Replay’ device. This was a small daughter board that you needed to install inside the case - it would piggyback onto one of the larger chips, and had several leads with pin clips which you needed to attach to specific legs of certain chips including the main processor. Finally it had a push button that you would create a hole for and mount somewhere on the case. When the Beeb was running you could press the button at any moment and it would freeze the machine. Then each of the red function keys would open a menu of options or direct functions. A key feature was being able to save the frozen machine state to disk (or ram drive) and be able to reload that state at any point. Naturally this was super important when trying to get past a difficult section of a game. Other functions were being able to modify variables/registers in running games to give more lives or extra features. It was a very cool mod! As a testament to how expandable this machine was, my Dad with a colleague wrote an entire engine test routine in Basic with live data sampling, on screen graphing, and plotter printer output. This was in an engine R&D facility in West London in the 80s. I still have the entire program printout. Neither of them were programmers before that task but they were pushing Basic really quite far, there was some heavy maths calcs going on in there.

The BBC master was probably the first computer I touched, at primary school. I learned BBC basic and Logo. It probably set the course for the rest of my life.

The RAM management was rather clever - it would bank-switch sections of RAM automatically depending on where the instructions were being fetched from, e.g. if it was executing graphics code in the OS, it would switch the display RAM to be accessible, OS code would access dedicated OS ram etc., so no overhead from software bank-switching

@adriansdigitalbasement

Жыл бұрын

That's pretty awesome. Some really clever engineering went into the BBC Model A/B and then this machine. It's clear the engineers at Acord really wanted to make an insanely versatile 8-bit computer. It's really a shame they never found much traction outside the UK with these 8-bit computers.

@paul_boddie

Жыл бұрын

@@adriansdigitalbasement Mike is possibly too modest to note that he designed some expansions for the BBC Micro, if I recall correctly. The bank switching arrangement he mentions is known as shadow RAM on the Acorn machines, and it was actually a matter of some controversy and even legal action between various companies in the Acorn market, although I am not sure that Acorn were ever pursued. The different Master series service manuals have the details.

Great video. As a schoolkid in the UK in the 80s I spent a LOT of time on BBCs, we even had a couple of Masters towards the end of the 80s. Great machines!

@mapesdhs597

Жыл бұрын

That sounds like an all too familiar experience. :D Did you have much of an issue getting access to them beyond what the prescribed work required? Alas at my school, the headmaster didn't like computers so it was always an uphill battle (he put the geography teacher in charge of them, who also didn't like tech), though some teachers ignored his directives and allowed students to access them outwith normal use anyway (I remember using the business studies teacher's Beeb one time, in his office, while he was teaching a class). One reason why I left school for uni at 17 was because sensible access had become so difficult, a distinct irony given the school had used many of my programs for teaching, including a chemistry database and a maths fractions tutorial for the remedial classes. Getting to uni was a surreal experience. Though studying comp sci, I quickly discovered the biology lab, an entire room full of Beebs, with pretty much nobody there, and anyone could use them. The main lab tech turned out to be an intriguing guy, he was one of the first people to write a save game editor for Beeb Elite. The contrast to school was palpable. As an 80s school kid, I guess it all depended on exactly which school one attended, the nature of the teachers, etc. The full spectrum of experience from dislike through ambivolence to ardent support and promotion. Perhaps some places had a supportive head teacher but the individual teachers were not so keen. There was only one classmate who had a Beeb at home though; most had Spectrums or C64s, if anything at all (most did not). I had an Electron, hence being able to write compatble programs. Decades later, I have a huge collection of Acorn machines, mainly Beebs, Electrons, Masters and Arcs, and one RISC PC. Hmm, acquisitional revenge/overcompensation perhaps. :D

@Gannett2011

Жыл бұрын

@@mapesdhs597 I was at a boarding school, and the computer room was open in the evenings, so we had a lot of extra time to use them. At our school it was the history teacher who taught computers!

@mapesdhs597

Жыл бұрын

@@Gannett2011 Excellent! And a fascinating contrast. I had a friend who went to boarding school, he lived in north London; he had a C64 but only had access to it when he was back home.

For the keyboard switches I've found Electrolube EML to be excellent. Spray copious amounts down the key stem and operate a few dozen times and even dead keys return to normal. DeOxit may work too but I'm not sure it's reducing agent is quite as strong as EML.

I can testify all the schools in England I went to in the 80s used this beast of a machine. They taught us to change lines of code to augment our experience, yes games were played on this machine using at least some of its vast attributes

its funny how you never hear about these online but for me this is the only retro system i had ever interacted with until recently thanks to them still being used in my school in the 2000s I remember in highschool physics we were using these to do like basic acceleration calculations and stuff and it had basic graphics to demonstrate the principals of the lesson. it was actually cool thinking about it in retrospect, that these old machines were still serving their original purpose that late

So good to see the Master again! My sixth form college (ages 16-18) had two rooms full of these in 1990.

About the BBC being a way to get kids learning about computers, the whole thing was wildly successful, it certainly got me interested in computers at the age of about nine and I never looked back. At the very least, I think it was part of the reason they 8-bits were so massive in the UK. We used this thing in school and we said, we want to do this at home, too, and the C64 and Spectrum came along just at the right time to capitalise.

As an electrical engineer, you nailed how select voltage power supplies work

This computer was amazing! The OS was super advanced and forward thinking

The networking was way ahead of its time. We had BBCs in Australian schools and the network at my school spanned two campuses with about fifty machines, about half masters and the rest model Bs. There were a number of shared hard drives (20MB I think). The networking had individual users with a log in. A group of friends and I had a constant challenge of finding and then hiding a "privileged user" from the teachers. I fondly remember the command "*PRIV". Most of the time, the only hacking was to get access to the games folder on one of the shared hard drives but one time I did hack into one of the teacher's folders and was able to get a copy of an upcoming exam paper. The teachers never found out about it but it seemed that most of the students in school knew and I was inundated with requests to hack more. I was totally scared that the teachers (and my parents) would find out about it, so that was the end of my hacking days. However, it is very nostalgic thinking about those days now in a fond way. Thanks, Adrian, for everything you do.

@bluewinds10

Жыл бұрын

Being in Australia, I'm, guessing this was in the 90's

@stephenwhite506

Жыл бұрын

@@bluewinds10It was 85-87. The school got model Bs in 85 and masters in 87. They were incredibly expensive. Students were allowed to fool around on the machines during lunch time. By 87 it was so popular that each lunch time the room was full. The teacher responsible for the machines then implemented a rule that you could only come in at lunch time if you programmed in Pascal. At home, most of my friends and I had a C64. Only one rich kid had a model B. We used to give him crap because it only had 32K and cost four times the price of a 64. It was a great time, and I learnt a lot that set me up for my programming career.

Adrian: It's freaking working! Keyboard: You sure about that?

My Brother and I were lucky enough to have a 512k Master to muck around with. Great machine to learn on, even ended up learning assembler. Fun Times! Fond memories of playing Repton, Exile, Nightmare, Bone Cruncher... for hours!

The reason they could get away with the thin cords on the UK variant is because there's (supposed to be) a fuse in the wall plug "sized appropriately for the load", in this case likely 3A which has red markings, the other common size is 13A/brown which is the legal maximum but 1A, 5A and 10A fuses also exist (these have black markings). The fuses are supposed to be sand-filled to extinguish any internal arcs if they blow. As a result the power cable can be fairly thin and still be safe! While the UK "fuse in plug" design is touted as a safety feature over other system the core reason this was done is that many UK outlets are on 30A or 32A "ring circuit" so without they couldn't use standard power cables (rated for 16/20A). It DOES have some safety benefits and their plug is probably the best out there, even if the benefits aren't nearly as big as many of it's proponents often claim. And yeah, as you note PSUs of this vintage tend to just need load on one rail, all the other rails (voltages) are based of fixed rations of that so as long as the "primary" rail has load it should be fine. Even today there's (cheap) PSUs with just regulation on one rail, though that regulation and switching is done via ICs and will run without load. This kind of "group regulation" tends to cause issues with "cross-regulation" but for a vintage computer it should be fine. Better modern PSUs either regulate each rails separately OR just create one or more 12V rail(s) and then any other voltage is done using DC/DC converters - not sure it's even possible to hit the required efficiency levels for "80 Plus" Platinum or Titanium certification without going the DC/DC route for minor rails.

It's great that you've got a Master now, probably the one of the finest 8-bit machines ever made! Keep the videos coming, I think you'll enjoy exploring just how much they can do, at the very least, put a gotek on it and get some software, and the Pi-tube is a must-have nowadays, nothing quite beats playing the co-pro edition of Elite! It's also worth exploring the programming side, BBC BASIC is probably the most powerful version of basic BASIC there is, with some great functionality, and an in-line assembler that makes machine code routines super-simple to implement. Check out the "advanced user guide" to have your mind blown by just how powerful this little beige box is! I'd suggest pulling all the key-caps (take a photo first!), then giving the switches a good blast with a IPA or contact cleaner, and working each key until it comes back to life, that usually does the trick. Although it has been for a long voyage inside a cardboard box, so maybe re-flowing the key=switch solder joints might be needed.

We had a single BBC machine at my primary school. I remember when I went up to high school we had a computer room full of rows of Acorn Archimedes machines. I can't remember a thing about those but I remember everything about using the old BBC.

brought me back to my youth, we had these at school when i was wee, was born in 81 to, was the firstcomputer that i got my hands on

First computer I ever used in the workplace, loved it so much I bought one, no longer have it sadly but still love it.

So there were some NTSC BBC Micros. (I don't know about Masters.) The problem is that the BBC was designed for the larger PAL video format, so most of the BBC Micros' video modes were 256 pixels high, which won't fit on NTSC. So, the NTSC BBC Micros had a tweaked ROM which used 240-pixel video modes. This ended up being 25 characters high rather than 32 for PAL. The end result of this is that hardly any software written for PAL BBCs would work on NTSC ones...

I bet whoever used this machine at the BBC back in the day would be blown away by how much computers run a modern TV studio (assuming they haven't worked in the industry or been retired for a while). We're building a new studio at work and pretty much everything runs off an Ethernet fabric network. There's no huge vision router with hundreds of video inputs and outputs, the network carries all the audio & video to/from the cameras, monitors, and everything else. It has two 400Gbps backbones, with switching capacity over 25Tbps (yes, that's terabits per-second) for each spine switch. The video streams are multicast, and the "video switching" of the streams is done in software (it's basically a software-defined network). Oh yeah, and the cameras are robotic and fully remote controlled entirely by software. The camera operator can sit it the control room and can move any of the cameras pretty much anywhere on set using a joystick. They can program their camera moves, and it will repeat the exact same move perfectly for take after take. For a single host news program, they don't even need camera operators. They just program the camera moves in the first recording, then as long as every broadcast sticks to the same format, no camera operator needed. They don't need a vision switcher or graphics operator, because the switching between the talent, graphics, and rolling clips is pre-programmed into the rundown. The lighting is all pre-programmed and also robotic, so no lighting director. You can basically run an entire live news show with 4 people, including the talent. Of course, if you're doing interviews or have multiple anchors or a weather presenter, or anything that might need manual camera switching, you'll probably need more crew than that. So yeah, things have definitely changed a lot in the relatively short time I've been in the industry, let alone since this computer would have been used at the BBC. Thankfully as a network engineer, my job is pretty safe. Software can't troubleshoot and fix a faulty network cable or dirty fibre!

My first computer was a BBC Model B and it helped me get my first job. This was providing some computer training to some students at an agricultural college. There was a Level 1 Econet network of BBC model Bs. Later, we added a couple of Masters and upgraded to a Level 2 Econet network that mimicked the ADFS hierarchical filing system the Master128 used. (Level 1 was quite limiting.). I never owned a Master128 but I added lots of accessories to my model B. A third party firm (Solinet) allowed me to use "sideways RAM" that could use images of the ROM application & utility chips. I wrote a service ROM image (called RAMBO) that mimicked the SWRAM commands that came with the Master. I even had a box from Watford Electronics that housed the M512 card, allowing me to run DRDOS & Gem through the Tube. I'd used my model B from 83 to 93 at which point I succumbed to the Acorn A5000 ARM machine. I still own these machines but haven't used them in a few years.

I think that keychain is one of those “no touch” thing for opening doors / pressing elevator buttons.

Great to see the Beeb getting some love from the US. My school here in the UK didn't have them (we had the RM 480Z and RM Nimbus series (z80 and 80186 based respectively) but I remember even seeing some in university science labs as late as 2001!

@kevywevvy8833

10 ай бұрын

we had the 480Z at school as well, the old black metal ones, I asked the teacher for the user manual so I could program the hi res graphics.

The 1Mhz bus ran at 1Mhz because a lot of peripheral chips still only ran at 1Mhz and the main CPU runs at 4Mhz. It was to simplify interfacing. The CPU actually slows down when it accesses addresses on the bus. The 1Mhz bus is also available on the cartridge slots but at 2Mhz.

I think we would definitely say "eek-o-net", rather than "echo-net".

@edgeeffect

Жыл бұрын

Yes... it's short for economical network, I think.

The early batteries used to be rechargeable and sat in the slot between the speaker and the cartridge slots. However they, and the charging circuit, were problematic, so they moved to the alkaline battery packs as a consumer item. That was a standard Acorn replacement part.

@kaitlyn__L

Жыл бұрын

I wonder who had the miserable job of connecting and heat shrinking those battery packs in the Acorn office all day 😅

I used to be tech working on BBC computers way back in the day. ARM has had several itterations. Back in the days of the Archimedes is meant Acorn Risc Machines, then dvanced Risc Machines, Econet itsEconomic Network, and as far as PAL to NTSC is concerned, if you have the parts it's a piece of cake. The biggest pain is finding an NTSC modulator. that can handle standard video signals. Unfortunately they are as rare as hens teeth and you "can" use the NTSC encoder from a Timex ZX81 from the US market, but it also needs some tweaks in he timings for the line rate etc. A friend of mine is a progrmmer and did this for a Dragon 32 but it drove him bonkers.

Many BBC micros were used in research laboratories in the UK because they are so easy to interface via the 1 MHz bus and a PIA chip, plus you could do all your data analysis and write your report all on the one machine. Its built-in BBC BASIC interpreter was superb, and included a 6502 assembler. The MOS was also very well done. The analogue input has a 12-bit ADC, which can be used for measuring voltages; however, its voltage reference is not very stable, so a common hack was to replace this with something better. This is possibly the best of any of the 8-bit machines of its era, and the BBC Master is the best of all. By the way, there was also a weird three-box solution called the Master Compact, which included a 3.5-inch floppy drive in the base unit.

Oh My! That's the computer of my childhood. I spent years using Acorn PC's including the BBC Model B and the Master with the additional Turbo 6502 Co-processor. That PSU cable gland would be called a Cable Grommet in the UK 😁

We had 2 BBC masters at my primary school. I loved them so much my parents got me an Acorn Electron. I used to know everything about that computer. I remember writing machine code to "race the beam" and change the video mode vertically. So It had different video modes on the left right and centre of the screen.

We had BBCs in my school for computer class (the Netherlands) but since we either had a ZX spectrum or a C64 at home already really never paid much attention what this machines had to offer other than some basic exercises we had to do. So looking forward to some of the follow up videos to see what I missed !!!

The cool thing is the Tube connector that was used when designing the ARM processor. Apparently it's quite a popular now.

I received a model B one Christmas and the following year a monitor and disk drive, it was the bees knees at the time, We thought my school would adopt the BBC as their official computer but instead got a Research Machines 380Z, I own that exact machine now and the twin external 8" floppy drives and one 5" drive and the 8 colour board that the computer club that I ran raised money for, the caretaker was having a clear out in 1995 and found my name on one of the books, being a small village everyone knew everyone and he contacted me to ask me about the machine and he ended up giving me it. I had the chance to buy a Viglen a few years ago but ended up passing on it, I still have my BBC but dare not start it up until it has been at least re-capped.

Network 23? i.e. Max Headroom? ;-) Don't know much about the Beebs... Looking forward to finish watching this vid. Thanx!

Econet is a really cool thing of the time. As you mentioned, the Econet is a network where you can connect all these BBC computers together. One Acorn BBC Master can a centralized fileserver with an harddisk where all the other computers can store data. You could also send text messages via a BASIC command from one computer to another. You can also print to the central computer.

@hjalfi

Жыл бұрын

My school had one! The Winchester hard drive had a squeaky bearing and shrieked loudly, all the time, and of course it was all hermetically sealed so it was unserviceable. We had to put it in a soundproof booth. Econet was a pretty capable system not dissimilar to TCP/IP, but of course back then nobody had heard of security. Login passwords were sent over the wire in the clear, and by default each computer exposed services which would allow you to read/write memory with no authorisation. A ten-line BASIC program would dump the video memory of someone else's machine so you could watch what they were doing.

@truckerallikatuk

Жыл бұрын

My school had econet, and it had an Apple IIe of all things to run the hard disk. Wonderful system.

@paul_boddie

Жыл бұрын

@@truckerallikatuk I remember a network of Beebs at my secondary school being run by an Apple II series machine. I am not sure it used Econet technologies, though, since there were alternative network systems available at the time, but I don't know what that particular system actually was. Some details would be rather interesting.

@dwayne_dibley

Жыл бұрын

*I am supervisor ah those were the days

@impablomations

Жыл бұрын

@@hjalfi We discovered you could 'hack' the network by mashing the Escape key when you turned it on as it connected to the network. It would bypass the login and you'd end up in the Winchesters root directory. This of course contained all the games the teacher let us play on special occasions.

Used light bulbs in the Telecom Industry for checking filter caps, that had developed high leaking currents, beyond acceptable levels. All filter caps had their own dedicated fusing, to protect from shorts on the DC Power Buss.

such nostalgia for me. My high school in San Diego, CA was completely Acorn in their computer lab and I was a big geek. I was one of about 5 students that would help the teacher keep them up and working. The echonet was a daisy chain network configuration, so some troubleshooting was involved regularly for bad connections or an occasional bad network daughter board. All of our Acorns had 3 selectable ROMs in them. One for basic, one for the Acorn word processor, and one for the Acorn spreadsheet. You could either type "basic", or the keyword for the other 2 roms at the asterick prompt or you could press and hold a key combination to auto boot to the desired one at power up. I believe that waiting for file system message was it trying to talk to the server over the network with the 10 or 20 meg hard drive in it, but that was back in the 80s, so my memory could be faulty.

Another cool video :D. The difference between a Master 128 and 512 is the 80186 fitted internally. The not a language is nothing to worry about as the battery has failed and cmos is scrabbled. *basic will get you into basic and a useable machine. There is plenty of guides on how to re-configure the cmos and it is easy to do. The tube processor can be any cpu, and the raspberry pi add-on emulates 6502, z80, 6809, 286 and other cpus, also run in ARM native mode. The 1MHz bus is used to connect hard drives and other peripherals, including midi controller and 8Mb of memory. The cartridge slots on the top is used to to populate 4 slots of the sidewise ram. All BBCs can handle 16 sidewise rom/ram slots in software. The varies manuals for the machine are easily obtainable. The econet can be changed for a ethernet card to allow some network access to modern machines, such as file transfer.

I'm pretty sure the analogue port at the back was for joystick control. I had a BBC Micro model B as a kid (32k), and we had the BBC Master at school, with laser disk :) I recently found an old BBC book, which probably came with my old machine... Unfortuntely, I no longer have the machine :( Isn't "DFS" for disk file system? It might be expecting a huge floppy disk (and disk drive) It might be that the basic ROM is not installed on there? I remember something like "Shift and break", or "Control and break" (one of those - it's a long time since the 80s) was the way of softbooting the system, where it would try to boot from floppy disk. The old cassette games on the BBC Basic seemed to often (but not always) require that you load them with chain "" or as me and my sister used to say: chain diddle diddle.

@snafu2350

Жыл бұрын

Ah, *CHAIN"" Fun memories from trying to load stuff from cassette (sometimes recorded from the TV series)! How I wished for a FDDD back then! :)) IIRC Shift-break auto-loaded stuff from FDD if available; it was the soft-break option. CTRL-break was the "hard" soft-break, which tried to reset everything to POST status, but even that wouldn't work occasionally (ISTR *FX124, would lock the machine until a full power off cleared it) The BBC BASIC ROM may indeed not be installed, esp if this was a systems control machine; fortunately that ROM image is now easily available for download

Acorn prototyped the ARM chip using this machine and its tube connector. It worked the first time they plugged it in, and then someone realised they’d forgotten to connect the prototype chip to the power, yet it was working anyway from the trickle of power the data connection gave it. That’s when they realised just how power efficient their new ARM design was!

Our computer studies teacher setup the econet on all our BBCs back in 1986. Unfortunatelty he left the user manual out one lunchtime and my friend and I went through listing all the commands. We spent ages messing around with it. Sending messages to screens and watching peoples reaction and stuff. We got so engrossed in what it could do we almost forgot to do our Computer studies exam project. Good times!

@AdriansDigitalBasement. That’s a Futaba Linear keyswitch, they have silver plated posts and a leaf spring and cam construction. They have an amazingly long life but by now most of them are beginning to age. I love them but find them hard to get. Treat them with kid gloves and there are tricks to dismantle and clean/repair then if you get desperate down the line.

Fun fact: the battery pack was expensive to replace. However, if you bought a three- or four-cell holder for the AA batteries, it was possible to replace the batteries with less expensive ones and maintain it yourself. I know because I used to replace the 4.5V packs for an easier maintenance schedule.

Love your videos and much love for BBC, being lucky enough to grow up in their golden era from release! I can;t belive that power strip almost screwed you...damn! :D

We used to have these in my middle school here in the UK! This computer is one of the reasons I'm in IT today still 35 years later!

4:55 it’s designed to use the earth pin to open the internal socket shutters for the live and neutral pins. That’s why the earth (top pin) is longer. It also has its own fuse that can be replaced. Newer UK plugs also have plastic shields around the base of the live and neutral pins so they can’t be shorted if partially inserted in the socket.

@OscarSommerbo

Жыл бұрын

I really think that the UK plugs are the best designed plugs in use. The only drawback is the chunky size, EU size "feels" better, but that is probably because I have been around them for my entire life. The less said about US plugs the better, except as a cautionary tale. Seriously, they seem to be designed to electrocute careless people.

@hjalfi

Жыл бұрын

@@OscarSommerbo You should see Australian ones. All the jank of the US plugs, at twice the voltage! But yeah, UK plugs are a marvel of overdesign. There are so many deliberately-designed-in safety features. (Did you know that one reason why there's an extra loop in the earth wire is so if you yank the wires out of the plug, live and neutral disconnect first and only _then_ the earth comes loose?)

@AcornElectron

Жыл бұрын

@@hjalfi I did but yes it is another one of the ingenious additions that the British Kite Mark used to denote! Add in variable strain relief and cable capture within the housing and I think we’re up to 2023 in safety terms. Of course, we DO get moulded plugs on some devices in the UK which is a bit more restrictive but still let you replace the 3/5/13 amp fuse and you can always just chop it off and wire up a new one.

@kaitlyn__L

Жыл бұрын

I don’t know why, but that mention of the ease of putting your own plug on made me hear “We really should get a plug on this turkey carver, Rodney” in my head. Haven’t thought about either OFAH or the pre-preinstalled plug days for at least a decade!

@hjalfi

Жыл бұрын

@@kaitlyn__L I remember the change from round pin to square pin! I think the round pin plugs may not, technically, be obsolete --- it's just they are 5A, 10A and 15A while the square pin ones are 13A. I think.

I like the way you know which cap is likely to go bad from the circuit topology and heat sources.

Me and my mate down the road both had BBC Micros as kids. Probably because we both had teacher parents. All we really wanted at the time was a Commodore 64 for the games. But now I’m so glad we had BBCs because I used to type out basic and assembly language from magazines which inspired my interest in computing and I think that was unique to the BBC Basic language. You could go into assembly to do some speedy graphical stuff right there in-between your basic code.

I have the BBC Micro B+ version - the one before this. I am running the SD card reader that plugs into the Disc Drive connector and has all the software it ever ran on a 128GB SD card. Mine came from a museum, I got two of them and so one for spares which I have needed. I have done the Power Supply Caps update, and its running well. I drag it out at Christmas time so I can show up my kids on Arcadians. I learned to write BASIC at school on one of these, my first paying job was a PC program for stock control at a local store, bought my first motorcycle cash. Happy Days

I grew up with these machines. This brings back good memories!

That this machine was at Broadcasting House is really quite something. I wonder it it ever made an appearance on the "telly" i.e. was filmed for broadcast. The famous hands that (may have) stroked that bust, old keyboard! ;D I was a pupil at the time these computers were (still) in schools--they were around well in the 90s and possibly further--so have the same fond memories as others do but surprisingly I haven't explored them much in emulation although I have dabbled a bit. What I'm saying that I sadly don't know where you can find much more than what a Google search will give. What I do know is that some of the educational software of the time is still under licence and so (I presume) impossible to get, sadly. I while ago I had a deep delve into this and found the original producers but I couldn't say now where or who that was unfortunately. This software was still in use in the late 90s, emulated from networked storage (CD perhaps?) on Windows for Workgroups PCs. At the time we took this for granted but that is pretty incredible now looking back. There was a very popular simulation of the battle of The Somme. Students could decide the plan of attack with every outcome deliberately being a failure. Children wouldn't understand this though and kept trying to win... There was also a music quiz board game that everyone memorised the answers to because they sure as heck didn't know any of them from their education! There were others too all accessed by 'desktop' shortcuts but those two were the ones that stick in my memory. One day I will do a deep dive into trying to find ROMs. If you want to play games then Bonecrusher is well worth checking out although I think that one had many ports at the time.

@markrobinson8237

Жыл бұрын

It's unlikely that it appeared on the telly (except as a prop maybe), because if it did it would have had a genlock card in it. I suppose it could have been removed, but I think various PCB tracks had to be cut to fit it, so the machine wouldn't work if it was removed.

@kaitlyn__L

Жыл бұрын

@@markrobinson8237 I was thinking about the Look Around You title sequence, although IIRC that’s a model B, hadn’t thought about a genlock being necessary but makes total sense.

Loved the old BBC, and the old BBC Micro Computer. Burned reefer.😁

I love the pure disdain for the broken power strip. I think that hurt Adrian to his core that something so fundamentally simple could have been the issue.

Analog was the Joystick / light pen port - and the punch out on the keyboard was for a voice ROM, the speech synthesizer addon wasn't popular, I believe it was a limited, fixed word one rather than a phonetic. There was quite a range of models, from the original Model A (16k), B (32k) - with an unofficial intermediate of A-32 upgraded with just the RAM. The B+ and B+128 and the Master, along with a host of aftermarket expansions, with Watford Electronics and Solidisk being among the most widely known (typically extra ROM space or sideways RAM)

@petergathercole4565

Жыл бұрын

The default Acorn speech ROMs (PhRoms) used samples recorded by a fairly famous BBC News presenter called Kenneth Kendell. They included whole words as well as individual sub-word sounds called phonims, but they were a pain to assemble into usable speech. A software publisher called Computer Concepts came up (or bought from the original developer) a much more versatile software only system that would attempt to speak typed text, run as "*speak" commands. This was available as a normal program, and also as a sideways ROM. This was really impressive as a program running on an 8-bit micro!

Awesome that you are doing something other than an Apple computer, I still think that there's not enough content on KZread about the Coleco Adam computer. It's a fascinating device with a interesting history.

I remember watching the BBC companion TV series every week with great interest and envy

At school we had a teletext adapter connected to the 1MHz bus on one of the machines, and you could download software that was transmitted on the BBC's 'ceefax' teletext service. Unfortunately, our television reception wasn't great, which usually meant it took much longer than it should have done to download anything.

You have no idea how stoked I am to see a BBC Micro in the basement (and the GOAT Beeb at that!). The Econet card is a nice surprise too! The only trouble with the Master is resisting the temptation to soup it up. There are many things you can do with a Master (and even a Model B for that matter) if you have enough spare Raspberry Pis lying around. 😁 Then there are things such as a multi-ROM switch, SD card storage, an upgraded video ULA... it can be a real rabbit hole. Ask me how I know...

@adriansdigitalbasement

Жыл бұрын

The Master appears to use a 6845 -- which I think is different than the ULA on the original Micro? Because of the 6845, the Master has nice razor sharp 80 column text. I can't recall if the original BBM Micro has 80 column text or not. But yes, I don't think I'll be adding the Pi stuff, at least not until I've played around with what the stock machine can do. The good thing is learning about this machine will help me understand the BBM Micro and the Electron too. :-)

@Retrospective1982

Жыл бұрын

I've dropped deep down that rabbit hole. Currently standing at 2 X RAM/ROM cartridges, Econet to Ethernet board, Original 512 80186 internal co-processor, 1MHz Pi SCSI board with a Pi Zero, Pi Tube board with a Pi 3A, Gotek floppy and finally a 5 1/4 floppy.

@hjalfi

Жыл бұрын

@@Retrospective1982 If you want to go even further, did you know the Master can read high density floppies? You just need some creative programming, because the data rate is so high that there's not enough time to service the NMI, read the byte, and then return before the next byte comes along. The solution is reentrant NMIs...

@geeempee

Жыл бұрын

@adriansdigitalbasement the original Beeb also used the 6845 and also a custom video ULA. The video ULA did extra things like colour pallette remapping and Teletext mode selection and most importantly clock division for 80 column modes. The 6845 just provides the CRT timing signals and memory address generation for the video. The original Beeb has 80 column modes.

I grew up on these. I have... _opinions_ on the design, which is in some ways great, and in some ways terrible --- that 128kB of RAM is split up into lots of little dedicated chunks, and you can't just map it all into memory for big bag 'o RAM games like you could with the C64. This means that you're kind of stuck with what kind of programs you can run on it. (There is, however, a version called the Turbo which has a complete second processor with its own 64kB of RAM internally, and the two work together as a multiprocessor system, which is frickin' awesome.) But the 65c02 processor is great; a bugfixed 6502 with some extra and very welcome instructions (inc a!); the disk hardware is _so_ fast, capable of reading a track into memory in a single revolution, quite unlike the C64! It even has a hierarchical file system. The star of the show is Acorn's MOS, the operating system, which is one of the best 8-bit operating systems around. Pluggable file systems, proper system calls, multiple utility ROMs which can get paged in and out automatically by the OS... it's a delight to work with. (The Agon Light ripped it off wholesale for their OS!). I have, BTW, just done a port of CP/M to these machines, among others...

We need to get Adrian a couple RISC-V mugs now...

The micro and master were released to accompany a BBC educational TV series back in the day. It also went nearly every school in the UK due to the 1980s "Computers for schools" campaigns.

I love listening to you work while I'm doing network or systems changes at work. Thank you for the time you invest for long form content.

@billfusionenterprise

Жыл бұрын

also good fro ASMR

I've always been in love with this computer. I've never had one, but used one in school. The keyboard was fantastic. the amount of tinkering that could be done was unreal. I remember being able to "lock" the machine to prevent it booting, then when the teacher came over, I'd press some magic key combination and have the machine mysteriously working again. The fact this machine probably belonged to the BBC fascinates me. I'd love to know what the machine was used for. They were probably used internally for a lot of things. I know they were used to control lighting grids in studios, also used for on-screen graphics for gameshows (and possibly to control the scoreboards / other studio elements via serial). I woulder if that EPROM could unlock any secrets about the machine's past? Looking forward to a part two!

At 41:00 it is the light bulb warming up not the power supply, bad terminology. The bulb is still passing current immediately once the power supply starts up. You just can't see it because the element is cold.👍 Also great job explaining the 240v to 120v mod. It is exactly as you described. If anyone wanted to know more detail here is how it physically works. When the mains is in the positive half of the wave (Hot is + and Neutral is -) one of the two capacitors is charged through one of the diodes and returning through the jumper link back to Neutral. Then when the voltage flips (Hot is - and Neutral is +) the other capacitor gets charged through the other diode in the opposite polarity. Turning the full bridge rectifier that it would be using at 240v into two half wave rectifiers with reverse polarity protection diodes across the capacitors. Hopefully this helps clarify it for anyone who was curious. Also the big switch that is on "dual voltage" supplies is just a switch making that same connection instead of a jumper.

Good information for 120v conversion as I begin my search for UK machines to add to my collection. Looking at getting an Acorn Electron as my first micro.