Oh man. What a walk down Memory Lane. My parents bought me one of these for Christmas when I was 12, and I used it to learn 6809 Assembly, and that has led to a 20+ year career in programming - I now write world-scalable cloud software. I remember reading the thick 6809 reference manual for hours, the "Z-Bug" plug-in cartridge debugger, and the cassette recorder you stored your data on. I remember learning to solder to upgrade the RAM from 16K to 64K (who will ever need more than that???). I remember taking on an extra paper route to earn money for the $200 (!) floppy drive. Probably the best thing my parents ever did for me was buy me a CoCo.

@jimb032

6 жыл бұрын

About my same story! I had the "Editor Assembler with ZBug pack" too, a COCO 2, and upgraded to the COCO3. Best gift I ever got!

@JarOfRats

6 жыл бұрын

I started with a 4k Timex-Sinclair 1000. It was a birthday present from my parents. It was best as a door stop. 4 failed within 2 weeks. We ended up returning it and my parents got me a 16k CoCo 1 for Christmas. That ended my allowance for a long time, since that thing cost a relative fortune at the time. I learned to make my soldering iron do the Triple Lindy when I upgraded the chicklet keyboard. The aftermarket ribbon cable was very thick and unwieldy and partially tore out of the keyboard's circuit board...so I had to solder a few tiny jumper wires. Scary.

@joepup8348

4 жыл бұрын

Good story! I loved the hobbyist industry that quickly sprang up around the Coco in the 80s. Companies like Spectrum Projects, one of my faves. Didn't get into Assembly then, but actually thinking of taking it up now for fun!

WIth a simple capacitive buffer, the DC level will drift depending on the content, but those converters can also be rather fussy, especially with 50Hz sources

@EEVblog

6 жыл бұрын

The problem was still there even without the AC coupling and using the recommended transistor buffer, so it's not that. The car rear view mirror was rock solid with AC coupling though but ultimately didn't look very good. So the ebay converter box is a bit flaky.

@vcr32

6 жыл бұрын

A lot of modern tv processing chips don't like the 240p signal that these older systems would often put out. (Since it was essentially a hack.) Perhaps that is the case here too?

@andygozzo72

6 жыл бұрын

most 'home' computers video signals did not conform totally to 'broadcast/official' standards, which modern tvs are designed for, some tvs are extremely picky, like mine...

@andygozzo72

6 жыл бұрын

many produced in particular a 'bodge' single frame sync pulse, instead of a correct pulse train, ,and some incorrect/missing 'back porch' level...

@simontay4851

6 жыл бұрын

Obviously in the 80s this would be connected to a CRT TV. CRT TVs are much less picky about the input signal. They'll just display what ever is input, pretty much.

I had a Coco 2 and I still have a Coco 3. Very cool machines in their time. They actually had a multitasking OS called OS-9 That was doing windowing more efficiently at 2Mhz than the PCs at 3.77Mhz. Ahh those were the days! When efficient coding and assembly were necessary skills to create software!

@JarOfRats

6 жыл бұрын

I had one a bit older than what's in this video. Mail-ordering a real keyboard was mandatory with those. I remember the horrific confines of 16k and the feeling of luxury when I upgraded the RAM to 64k. Then, inevitably running out again. Swapping subroutines from the disk drive became standard. I also remember swapping the ROM to RAM and modifying the Extended BASIC to suit my needs. I learned Assembler on that rig, too. LOVED the 6809e instruction set. I have emulators now...always toy with the idea of buying a vintage CoCo online.

LOL, you know you're old when you can remember going into the store and marvelling at them on the display stands.

Well I never clicked a video this fast, just love vintage computers!

Back in '81 we used to sell these like hot-cakes until the VIC-20 tapped the market. For a little while Tandy made a scaled-down CoCo called the MC-10 but I haven't seen one in years. As an assistant manager at the Toronto 645 Yonge St. store, they never paid me enough money to buy a C64 so I had to steal one... technically... Since my brother and I lived near the Commodore plant in Scarborough, we used to check the dumpster at night until we got enough parts to assemble our own working C64 (complete with floppy drive). As Charlie Bunker used to say, "those were the days".

@EEVblog

6 жыл бұрын

Great stuff!

@stargazer7644

6 жыл бұрын

The MC-10 was essentially a color version of a Timex Sinclair 1000.

@CliveChamberlain946

6 жыл бұрын

Our Canadian models had that "CoCo look" with the Chicklet keys. I think I opened one and saw a Motorola 68 series CPU (but not the mighty 6809).

@billpeiman8973

6 жыл бұрын

I remember that store: just north of Isabella St.

@CliveChamberlain946

6 жыл бұрын

Yup, just a hole-in-the-wall so close to Yonge & Bloor (proverbial arm-pit of Canada..) I always wanted to work at Paul Aire's store down in the Eaton Center. No matter how closely we kept vigil, we always had stuff stolen right out of our front display case on Christmas Eve. Elbow-to-elbow last minute shoppers, thieves and skin-heads.

One ROM is for Color Basic, the other is for Extended Color Basic.

@EEVblog

6 жыл бұрын

Oh, interesting, thanks.

@JarOfRats

6 жыл бұрын

Back then, Radio Shack would NOT sell you the Extended BASIC chip. You were required to bring your computer in and they'd ship it to the closest service center for installation (at an additional cost, of course). I think I was without mine for over a week. Mail order houses would happily sell you just the chip. The specialized service instructions were "take off lid, install chip in socket, replace lid".

@SteveJones172pilot

6 жыл бұрын

Or.. you took a cassette tape to your local Radioshack, and did a "CSAVEM" command to save the Extended basic rom to cassette, and took it home to burn your own EPROM.. Not that I'd know.. :-)

@Enigma758

6 жыл бұрын

I recall the articles which told you how to burn your own EPROM but left you on your own to somehow get a legal copy of the contents.

@dh2032

6 жыл бұрын

more info.

OMG someone got excited. Seriously funny

@coffee115

6 жыл бұрын

KungFu Master I laughed SO HARD AT THIS

@Gayestskijumpever

6 жыл бұрын

That genuinely made me laugh. Good old Aussie humour!

@tohopes

6 жыл бұрын

"No comment" after ... after... Geez, Dave. Never go full Aussie.

@JennyEverywhere

6 жыл бұрын

Well it IS retro computer pr0n...

@simontay4851

6 жыл бұрын

But what really likely happened is someone spilt water on the manual.

The screen looked a bit crisper than that on NTSC models back then, but usually that took tweaking of the various analog mystery knobs on the TV. PAL was *supposed* to be crisper (but get you fewer "accidental" colors) on contemporary hardware...

@simontay4851

6 жыл бұрын

PAL is slightly higher resolution.

@MarkEichin

6 жыл бұрын

Right, but the use of color burst in NTSC vs frequency lock in PAL made more of a difference (as with the Apple II you could get extra colors by drawing vertical lines one pixel apart on NTSC, on PAL you actually got the lines...)

@ZomB1986

6 жыл бұрын

C64 @ PAL monitor looked about the same. I even found a special program that could switch the framebuffer from 40 to 80 horizontal characters, which made text literally unreadable. Altohugh when you actually view it on a low-tech monitor instead of upscaled on a TFT, you notice the bad quality a lot less.

@JarOfRats

6 жыл бұрын

We used to use a small subroutine to make use of those "accidental colors". It was called Artifacting- the drawing of 2 lines to create a 3rd color. If I recall, the command was Paint x,y or something similar. You could fill areas with colored patterns and a couple extra colors. I used it to make a BASIC Missile Command.

@ZomB1986

6 жыл бұрын

en.wikipedia.org/wiki/Composite_artifact_colors

Dave, thanks as always for giving love to vintage computers. I hope you can do a video on the BBC Micro some day so I can hear you rave about its beautiful design. I'm gonna put my neck on the line and say I don't think any 80's home computer can really compare for build quality. Come on you Brits, back me up!

@captainsausages1205

6 жыл бұрын

Yeah, the issue 7 boards were pretty indestructible. Dave did an Acorn A3000 here, by the way: kzread.info/dash/bejne/poSlmbF_Y8nRk6g.html

@electronash

6 жыл бұрын

ForViewingOnly The Beeb was and still is an amazingly solid machine. Only common issue are the X2 mains filter caps releasing the magic smoke, but that's no big deal, just as long as you hold your breath. lol I'm hoping Dave and everyone on the EEVblog forum has at least seen "Micro Men"? (there's a good 720p version on KZread.)

@simontay4851

6 жыл бұрын

I was 6 in 1990 and my primary school had a BBC micro. Obviously at that age I didn't know how to use it.

@deanolium

6 жыл бұрын

How about compared to the Apple ][? Really, that is a very interesting design which isn't too far off the BBC, but with the ability to really modify its abilities via adding in more cards. It even had a built-in assembler in the early versions, so quite equivalent in many ways.

@ForViewingOnly

6 жыл бұрын

Yeah, I was thinking of the Apple II when I posted the original comment. Another beautiful and reliable design, but I'd probably put the BBC Micro ahead of it for design & build quality... maybe I'm a biased fanboy. But the Apple did have the BBC beat by 4 years though (1977 for the Apple compared to the Beeb's 1981). The Apple is the only other 8-bit home computer I can think of with a built-in switch mode PSU like the BBC.

Those ROMs are Color Basic 1.1 and Extended Color Basic 1.0. The second generation of the CoCo "one" came with Color Basic 1.1. Fun note: This was back before BIOS days so some smart assembly language programmers leveraged code in the ROMs by calling directly to the starting addresses of the routines. This created an incompatibility between the old and new ROMs with some specialized applications.

I love vintage computers. This was an excellent tear down video, I loved seeing what was under the hood, well done for your perseverance in trying to get a picture via HDMI.

My very first computer was a CoCo. My dad brought it home just before Christmas in 1980 if my memory serves me right. It was an earlier production variant, with the black keyboard surround, the top badge shifted over towards the left side, and another badge on top near the right edge to indicate how much RAM was installed. I was instantly hooked, and my earliest computer programming experience was learning BASIC from those same books! Yes, the keyboard was awful. I always lusted after the keyboard upgrades advertised in the CoCo magazines... and I finally got one of them earlier this year! :) Old analog TVs often do a better job of dealing with vintage home computers than modern TVs and dodgy composite video to HDMI adapters, but the screen did look pretty bad by today's standards. On a contemporary analog TV, the screen would have a softer blurriness vs. the blocky jagged edges that you often get when converting to a modern digital display. NTSC models could make use of color artifacts to get four colors in high resolution graphics modes. I don't recall whether the PAL models can pull the same trick. I used that CoCo up through 1986, when my folks got me a Commodore Amiga 1000 to take to college. Though I must admit that towards the later days, I used the CoCo less and my dad's Lisa more. I still have that CoCo, though it was missing and thought to be long gone for decades. We thought that my folks got rid of it along with the old Lisa, but then it turned up in a box when my folks moved a couple of years ago! I haven't turned on my original one again yet, but I do have a few others that I've acquired once I became very interested in retrocomputing: A couple of silver CoCo 1 computers, one of which kame with the HJL-57 keyboard upgrade that I wanted so much when I was younger, a CoCo 2, and a CoCo 3. My CoCo 2 is one of the later ones made in Korea, in which they used an upgraded video display generator chip that's capable of real lower case. That wasn't officially supported by Tandy/Radio Shack for compatibility reasons, but it's possible to enable the lower case mode if you know your way around a soldering iron. The CoCo 3 is quite a bit more advanced than the CoCo 1 and 2. It supports 80 column video and higher resolution graphics, and there was a matching RGB monitor for it. It could be upgraded to 512k (officially) or more (unofficially) RAM, which was bank-switched into the 64k address space. The RGB monitor offered good enough resolution for 80 column text, unlike a color TV, but it didn't reproduce the color artifacts that many games used. Thanks for making this cool tear-down video! When you posted that teaser picture of the enter key on Twitter, I immediately recognized it!

This was my very first computer! What wonderful memories learning all I could on this machine! Got me started in computing back in 1981, and I have been doing so ever since then!

You could also get the "Radio Shack Color Computer Technical Manual" which was a publication of Motorola for Radio Shack. It was a true technical manual (about 80 pages) with complete theory of operation of all the major circuits in the TRS-80 CoCo complete with schematics. The publication is still available online. This manual along with the "Assembly Language Cartridge for 6809" were pure gold for this (at the time) high school senior.

@EEVblog

6 жыл бұрын

Yes, I have this linked in the description.

Really nice video. I really liked that you had done all the homework on the chips beforehand so that when you pan the video to them you immediately say what they are instead of just guessing and then looking them up. Thumbs up! :D

The CoCo 2 was my introduction to computers, and the CoCo 3 was my first home computer. Had that computer for about 5 years. I did so much with that. Those were the days. When I saw this video pop up in my feed, I clicked on it so fast!

I remember being a kid when my dad brought home a Trash80 Model III. He paid a ton of cash extra to go from 32K to 64K of memory. Good times!

@johnpossum556

6 жыл бұрын

It was under $100.

Boy, I could go on for hours about this machine. I had one back in the day, and to answer a few questions, #1, yes, once you got the video straight, that's about how good it looked on a TV, mainly because you're compressing the composite signal into RF modulation to feed into your TV antenna input. If you ditched the shitty RCA cable they give you with the unit, and use a really high quality shielded one, and you had a TV that "liked" the signal from the CoCo (some rendered better than others), that's about the best you could do with RF modulation. The composite mods DEFINITELY improved the video by leaps and bounds, mainly eliminating the herring bone interference pattern you get with RF modulation. The 3rd version of the computer actually had 3 different type video outputs... RF modulation, composite out, and CoCo 3 monitor input on the bottom of the unit. The CoCo 3 monitor was a digital monitor, and a proper computer monitor for the CoCo. It had the absolute best display you could ask for along with true lower case characters, (no fancy decenders mind you), along with 40, 64 and 80 column characters. The 3rd version could display up to 16 colors from a palette of 64 colors. Aside from the the slightly improved video, the 3 was mostly identical to the 1 and 2. Depending on the age of the MC6847, there is a way to kick it into true lower case on the color computer 2, not sure if the late model CoCO 1's were capable of that or not. The design essentially came from a terminal that was made first. A company called agVision wanted a cheap terminal to sell to farmers, so they went to Motorola who basically handed them the design you see in the block diagram, and instead of BASIC in ROM there was a terminal program. agVison needed someone to design, manufacture and distribute the unit, so that's when the approached Tandy. Smart cookies at Radio Shack realized they could swap out the terminal program for BASIC and have a general purpose machine rather than a task specific computer terminal. The price wound up being the same, so the terminal was soon canceled, and the same terminal software was available as a cartridge. A 4 connector expansion interface enabled up to 4 cartridges at once, hence, a disk controller, proper RS232 port, etc could be connected and software selected at will. Believe it or not, there's a still thriving CoCo community out there to this day complete with people making new software.

Great stuff. I like that you put in the effort of experimenting with it.

Hi Dave, Sweet memories on this computer, I learned Assembler for M6809E with this machine, Still got the book to program it, hilarius

I used to have one of these, my first computer... and had a manual connect 300 baud modem. What fun! It seriously looked that bad on my TV. So much eye strain.

I had one of those. I was able to upgrade the memory to 64K from the original 4K and added a different keyboard similar to modern one. Although the computer was very limited, it is what held my attention, got me started and gave me the interest to pursue a career in programming. I still have one and every couple of years I dig it out to remind me of what it was like back in the day. Great Video! Thank you.

Still a better resolution then my phones thermal camera. It's such fun to watch you. Also love your forum because that seems to be the only thermal camera enthusiast community on the internet.

I still have one of those sitting out in my garage. :) I liked the 6809E, especially when I discovered its PCR (Program Counter Relative) instructions, which allowed you to make a program completely relocatable so you could load the program along with its data anywhere in memory and because the data access instructions were PCR, it could still find the data. I wrote a machine-code program which could be loaded anywhere convenient in RAM and then called from a BASIC program to write text onto the high resolution graphics screen. The only other way of doing that was to draw letters using the graphics commands, which was slow and cumbersome. I'd usually reserve 6 "pages" of RAM for the graphics screen because you needed 4 pages for the high-res screen and I could load my graphics routine and data into the other two pages. The routine printed the full ASCII and IBM extended character set and had all kinds of advanced functions, like cursor positioning and even the ability to redefine any character using a BASIC call. Want a custom character for a game? You could send it to the machine code routine and have it replace a character you wouldn't be using in the program, then just print the re-defined character. Unfortunately, this was right at the end of the "life" of the CoCo and the IBM PC was taking over in popularity, so I never bothered to send the program to anyone. I probably still have it on a tape somewhere out in that garage, though.

i had a CoCo3 when I was a kid and used it for many years. still have it! and there is an active community of coco fans that are still tinkering, making hardware, etc :)

@ThroughYourWindow

6 жыл бұрын

Yep - facebook.com/groups/2359462640/ Hold on to the Coco 3, getting harder to get your hands on at a decent price.

@BrightBlueJim

6 жыл бұрын

The CoCo was and still is one of the most hackable machines out there. But then, I guess that was true of most of the 8-bit computers.

Thanks once again for a very informative video !

Well this brings back memories. I learned assembly on a Coco II in the 80s. They had a lot of software including an assembly language development cartridge called EDTASM ("editor-assembler"). They also had an entire office suite called "VisiCalc", which I probably still have. I helped a small engineering firm write code on it for a system to test diesel engines during manufacture on the assembly line at the 20 acre, Jamestown NY Cummins engine plant. It was the arduino of the time (sort of). We mounted the CoCo II motherboard in a big Square-D box and fitted the proper relays and drivers with 7-segment displays. We used 6821's everywhere for IO. Cummins was pleased and used it on their assembly line. Little did Cummins know a Coco II was driving their engine test rig! I did the composite video mod on my own machine and other mods as well, and then bread-boarded many various self-made projects including a digital sound sampler (stored audio in static RAM), digital light dimmers, graphic drawing programs... all written in assembly on EDTASM. The graphics were better (clearer) than the CoCo in this video, and it had a pretty good implementation of BASIC which was actually written by Microsoft. Wikipedia says Color BASIC was actually designed by Bill Gates. The 6809E (E = external clock) ran at 2 MHz. Spent many hours learning what would now become my profession on the CoCo II.

@BrightBlueJim

6 жыл бұрын

"Arduino of the time". That's what I keep telling people - Arduino is nothing new; all of the 8-bit home computers were highly hackable. It's just that a whole generation grew up with nothing but 32-bit computers that were much, much less friendly, so when the Arduino guys came up with a "new" DIY 8-bit platform, it was the greatest idea of all time. Sort of.

@RussTanner

6 жыл бұрын

Exactly. Processors like the 6800 and 6809 were very easy to work with, 100% static, and the family of chips, like the 6821, were also very simple. You could have IO up and running in less than an hour. The only catch was address decoding logic for connecting other chips to the address bus. Simple if you have a little experience. Nevertheless, it's amazing what we did with a 2 MHz processor back in the day. One thing I remember is boxes of cassettes. Using EDTASM, I had to store all my code on cassette tapes because the EDTASM cartridge occupied the slot the optional disk drive used, so you could not use them together. Never had a problem though. Cassette storage was surprisingly reliable.

Dave you just took me back to my childhood when I first introduced to BASIC programming on a TRS-80 at my elementary school! :-)

Power regulator using a TO3... that's really old school!

@silentbloodyslayer98

6 жыл бұрын

rarbi.art i was going to say the same, just like the apple I

I had one as a kid. My dad and I upgraded it, and did the composite video mod as well. We even built an interface cartridge and used it in the lab with an A/D converter!

Cool Stuff! TRS-80 also came out in 1980 my parents had one. I still have the first pocket TRS-80 computer and it looks and functions like new. this was the first time i learned to write code, i was 10-11 yrs old. I never saw this color version back then other than at the radio shack stores.

Am I the only one that finds stuff that was made before I was born fascinating? Thanks for the vid!

This was my first computer. My parents bought it for me Christmas 1980. I later upgraded to a CoCo 2 with "multi-pak interface", floppy drives, RS-232 pak, speech/sound pak, etc., and finally a CoCo 3 running Microware OS-9, a pretty amazing OS for the day running on the 6809.

Brings back tons of very good memories on the Coco. My very first computer. Got it with the stock 4k and then upgraded to 16k, which took a week, since there was no next day delivery, had to wait for next weeks truck from Tandy in Forth Worth to bring it. Spent hundreds, if not thousands of hours on that little jewel, before moving up to the Atari 800.

Had one of these when I was in grade school. Brings back memories. Spent many hours keying in a Frogger type game from the CoCo magazine. :)

This is my first computer and covered all those manuals then. Traded it in for the coco 3 + modem for 80 column 256 colour which luckily made the peak of 8 bit computing was amazing. Now I picked up coco 2 (soft round keys) and installed the composite circuit and get wavy lines.

boy does that bring back memories...i had the coco2...CLOAD...wow have things come far

I got relegated to art class in 9th grade, but didn't take me a lot of arguing to get my counselor to switch me to computer class. This was the first computer I laid my hands on and I've been pretty much hooked on it ever since. God bless those early pioneers; the world would not be the same without them.

My father got the TRS-80 MC-10. It is a really small computer, very cute. It was simpler version of the ordinary TRS-80 but with a very modern design. It was not a sucses but we had a lot of fun with it. I still have it somewhere.

That's exactly how it look, and we were amazed by it too!

Ahh, the memories. Got the CoCo 2 16K Extended Basic model for my birthday in '84 (sent it off to get it upgraded to 64K the following year), and couldn't have been happier! Text and graphic adventure games were the best, plus some clone games. Rainbow Magazine out of Kentucky had a monthly magazine dedicated to programming this machine, each month having a theme (business, music, games, utilities, etc.). Had a tape drive for about a year and a half, then dropped the bank for a disk drive (about $239). When you're exposed to today's technology and look back, it was primitive, but back in the day it was cool as hell.

You crack me up. I used to own a late 80s model radio shack built similar to what you have.

Seeing this video has me wanting to head out to our barn and dig out the working CoCo 2 that I have stashed there.

My first computer was a CoCo 2 bought in November 1983 with 16k Extended Color Basic for $150 or so. Over the years I added a printer and floppy disk drive. I used it as terminal for packet radio from late 1987 until the summer of 1988 when I bought a PC XT clone. With the Coco 2 I used an office suite word processor to write our local radio club's newsletter. The most ambitious thing I did with it was upgrade the RAM to 64k myself. I never took the plunge into OS-9, though. In the '90s gave it to a friend in Oklahoma and he passed away some years later. It's probably rotting away in the Garfield County, OK landfill. :-(

I had one. Model 1, 2 and 3. I learned on that at about 9 years old. Had a friend, we teached each other from reading the magazines, the basic programming language, and moved up from there. Local user groups, help me to learn to burn eeProm on it, and modifying the hardware. Definately learned more from those computers, landed a software developer job out of high school.

That was about right, from what I remember, concerning the display. Remember we were looking at it on a regular color TV. The display never was really sharp. I played around with one of these "Trash 80's" in the store at the mall. Ended up getting an Apple //e, then a Macintosh IIci, then a 6400. Ended up with a G3 and then a G4. Those were the days.

This pc got me into a 15 years of IT. Remembering using tape recorders to load and unload progs. Memories!

With the off-the-shelf parts and the datasheet-like construction, this is only one step up from home-building it yourself

When I was 13 I mowed lawns all summer long (pre kickstarter) to save up for one of these puppies. Was my first love. Recently picked one up from eBay and now use it to run a Spectral Analyzer in my studio (and play games when procrastinating). Good times!

Memory Lane for me. Started with a Co-Co and progressed thru the Co-Co-2 and 3. Still have that exact set of manuals.

I programmed a science fair project on a Coco 2. This little computer is suitably powerful enough even today to be useful for teaching BASIC programming. Oddly enough, the monochrome 256x192 mode is the basis for RLE images.

My Coco2 has (not had, has) a monochrome composite out and it's crystal clear even 30 years later. Under OS9 it runs 80x40 with real lower case and it's wonderful.

This was my first computer as a kid. (I was around 7 or 8)... I remember my dad brought it home and that was my first experience with coding. I would write all kinds of programs in basic. The model we got was a 16k version.. I remember my dad eventually upgraded it to 32k and then 64k by piggy-backing the chips together. The cassette player was always the weak link. That sound! And it would only work some of the time. When they came out with a 5.25 in floppy for it, it was so much better... Two biggest quirks... make sure you popped open the floppy door to pull the heads off the media before turning the computer on or off or you'll destroy the floppy. The most annoying thing was also a great feature. If you shift-backspace, it would delete the whole line. There was nothing worse than typing in a huge long program line out of RAINBOW magazine only to accidentally hit shift backspace. TO THIS DAY, I still catch myself thinking about releasing the shift key before I hit backspace.

One of the best things about the CoCo was the operating system, which was OS-9 by Microware, one of the first 8-bit UNIX-like operating systems. OS-9 was also a very popular industrial/commercial embedded operating system, especially on Motorola 68K VME systems. Many engineers using OS-9 at work had a CoCo at home to use as a (very limited) learning and practice tool.

@mheermance

6 жыл бұрын

Bob Cunningham Nitros-9 is an free open source reverse engineer of OS-9. It's fun to mess around with and a bunch of retro games are available for it.

@jimb032

6 жыл бұрын

That's the epitome of an ignorant comment. Sounds like it comes from someone knowing absolutely nothing about computers. It was and still is in many ways the backbone of the Internet.

@darkwinter6028

6 жыл бұрын

Vendicar Decarian - Got a smartphone? UNIX. (iPhone or Android - they both have a UNIX-like core). WiFi router? UNIX. (usually a variant of Linux). Smart TV? Ditto...

@JarOfRats

6 жыл бұрын

OS-9 was never standard on the CoCo. It was an optional add-on. The standard OS was the very simple BIOS underpinnings with a Microsoft Basic (or Extended Basic) interpreter overlay.

@johnpossum556

6 жыл бұрын

@James Kerns Jr: Obviously he's trolling this thread. Martin Heermance: Thanks for sharing that! It is amazing what I don't know existed until some one posts it. might tempt me to take those computers out of storage some day. Getting it from this HW to that HW could be an interesting challenge.

This brings back fond memories. I modded the daylights out of mine. Added lower case, new standard size keyboard, as mine was a version 1 with 16k only I modded it for 64k, added the expansion module, got a floppy drive controller that also held 4 EPROM's so I could modify the OS and burn new EPROM's. One of the last things I did with it was to add a 32 MB hard drive. Thanks for posting this video.

I was in 7th grade in '79-'80 and 8th grade in '80-'81. At the time, I lusted for the TRS-80 Model III, but couldn't conceive of affording one. I considered the CoCo a toy. A friend of mine bought one of the last 4K CoCos on clearance. He generally only used the machine when I visited him. I ended up using it more than he did! He had a habit of buying things and then quickly becoming bored with them. He offered to sell me the CoCo, a tape recorder, joysticks, etc. all for a pretty reasonable price. The Model III was a pipe dream. I decided that a CoCo was far better than no computer at all, so I bought it from him. After several months, I outgrew the 4K RAM and standard BASIC. I had a very good relationship with the manager at my local Radio Shack store. I took my machine to him and ordered the 16K RAM upgrade with Extended BASIC. Rather than make me wait for several weeks with no computer while mine was being upgraded, he sold me (for the price of the upgrades) a brand new machine from his inventory that already had the specs I wanted. He said he was then going to send my old 4K machine away to be fully upgraded to 32K, etc. and he was going to buy that machine for himself. This was pretty cool at the time, and later turned out to be quite fortuitous. After a year or so of living with the horrible TV video quality (yes, Dave, it *was* just as bad then, too!), I bought a cute little 9" monochrome green (composite video) CRT monitor and modified my CoCo with one of those same Darlington circuits you found. The image was beautifully crisp! The text screen was still 32 characters wide by 16 lines, with fake (inverse video) "lowercase" letters, but it was *much* easier to stare at for long programming sessions. I wasn't much into graphics or games. I liked learning about 6809 assembly language, so a crisp monochrome text display was a big win for me. (As Dave mentioned in the video, using the Darlington buffer circuit permitted continued simultaneous use of the RF modulator with a color TV. So I had both hooked up. For crisp text, I looked at my monochrome monitor. For color and graphics, I looked at the TV.) Somewhere along the way, I acquired a floppy drive. This was a *huge* improvement over the cassette tape! Eventually, I discovered magazine articles explaining how to swap out the 16K RAM chips in favor of 64K RAM chips, along with the associated circuit modifications (cut a couple of traces, solder a couple of wires here and there, take advantage of an unused NAND or NOR gate in one of the quad-gate chips). Voila! 64K bytes of RAM! (This is where it turned out to be fortuitous that my Radio Shack manager had upgraded me to a brand new machine a couple of years prior. The newer rev PCB required far fewer invasive modifications to upgrade to 64K than the older rev PCB would have required.) Over the next couple of years, I added the OS-9 Level I operating system. I continued hacking on this machine until I graduated from high school in the spring of 1985. I started college in the fall of 1985. Sometime around there, I bought a spiffy new CoCo 3! I eventually upgraded it to 512K RAM, the OS-9 Level II operating system, and a third-party *hard drive* system! The hard drive and associated controller set me back around $1,000 US. It was all very cool! Unfortunately, college left me little time to play with the CoCo 3... :-( The computing resources at the university sucked me in and I found myself using things like TOPS-20 on several DECSYSTEM-20 machines, some VAX/VMS, and mostly BSD Unix. In a few years, I was a fully-addicted Unix hacker. By the mid 1990s, Linux had come along, making an affordable personal Unix-like system a reality. I still have my CoCo I and Coco 3, but the other peripherals (floppy drives, hard drive) and software (all on 5.25" floppy disks) are hopelessly lost or damaged. I have a crazy dream of writing my own 6809 emulator that will run on Linux, on a modern mainstream Intel machine. I know that several such emulators already exist, but I dream of writing my own from scratch, just because... My dream also involves going well beyond the CoCo architecture to design an (emulated) machine with a 24-bit physical address space, a modern MMU, separate user and kernel modes, etc. I also want to build a real physical "lights and switches" front panel and interface it to my emulated 6809 computer. None of this will have any practical purpose... It will just be a project to do "because"... Someday. Maybe... Walt

My dad bought one of these for our family back in the early 80's. I remember playing their version of Space Invaders from the cartridge, and I learned how you program in basic on it. IIR, the cursor was called a "turtle" for some reason? Anyhow, awesome vid, and thanks for the nostalgia! And no, I remember it being quite crisp and clear on the Tandy CRT that we got with the computer. Cheers!

My first computer was the 4K model. Very soon replaced with the 64k Model. It was so fun and exciting!

I had one of these. I also had the CoCo2 and 3. I ran OS-9.

Wow, does this bring back memories. I learned to program on one of these. Couldn't afford one of my own, but I hopped on my bicycle every afternoon one summer, and pedaled five miles to the nearest Radio Shack, where the indulgent staff would let me stand at the display for hours on end writing little programs to make neat patterns on the screen. And yes, the display was always that bad. Although, by the standards of the day, it didn't stand out. I don't know about PAL, but in the NTSC world at that time, I think inexpensive TVs didn't even have comb filters, so they couldn't resolve much better than this anyway.

My parents came home with the 16K Coco in 82. My mom thought it was going to be another piece of wasted money. Then we fought over who could use the TV. Cassette tape drive for storage, a hand full of cartridges for game... Then a couple of years later we got the Coco 3. What an upgrade that was. And yes, that's how it looked.

Absolutely fascinating! I had a coco2 in 1982-ish? I think tandy/radioshack was selling both models for quite a while.. which is kinda crazy considering the first macs came out in 1984 i guess? You also solved a question I had as a 10 year old kid! My coco 2 had 16k of RAM, and I saw that radioshack sold those ram chips separately, but never had the nerve to open up my coco2 to see where/how to add ram to it! Seeing the socketed chips in your video made it clear to me! (35 years later)! Thanks for this vid!

I was 12 years old when I was given this computer for Christmas. I learned to program and wrote my own paint program with it. I upgraded it to 32k by soldering memory chips onto it. I went on to write code for engineering applications and eventually became the manager of engineering software support for a large company. Never got a college degree, I learned from this computer and later an Amiga. Who would have thought a Christmas present would give me a long successful career? 😀

I’ve done it all on the coco. Mine was vintage 1982 with 16 k and I upgraded it to 64k and replaced the keyboard with an expensive after market typewriter style one. I also disabled the Nmi Pin connection in the cartridge slot so games and otther applications couldn’t autostart without me selecting a switch. This allowed me to copy any cartridge based application to cassette and reload it in a different section of ram. I did lots of mods to the computer. I used a connector for direct composite video and sound. I used this computer so much I wore it completely out. I did all the os9 stuff as well. Once i discovered how to access the address and data buss on the connector. I would use peek and poke to send data to memory mapped devices under program control. This computer was my first venture into physical programing. Turning something on or off under program control was amazing back then. The joystick ports were another place to recieve input from the physical environment. With a CDS cell connected you could determine light intensity to somewhat of a degree.

Nice flashback. I had that trash 80 when I was 8 yrs old. And that book! I remember programming Lemonade Stall and saving onto cassette.

Yes. What you see on that LCD is what we got on the TV mostly. Not terribly readable but it worked for the time. :)

Thanks Dave! This was my first computer. Those basic books were awesome manuals to learn by. We also had a subscription to the users magazine "Hot Coco". We had a 64K Coco with fancy dual floppy cartridge attachment, and I spent many nights writing games on it in my youth; And in case you didn't know: I invented Disk Caching. : D We also had hacked in a speaker with amp and volume switch to keep from annoying the parents too much with late night sessions.

Awesome demonstration. Tandy Corporation, Motorola and National Semiconductor collaborated to create the Coco, so thats why its almost all Motorola chips. Either your model had an 64K upgrade kit or Tandy upgraded it so it'd compete against the C64. And dont go knocking on Radio Shack. They might have been a failure outside the USA, but in the USA they sold a lot of computers in the 80's.

@JarOfRats

6 жыл бұрын

Originally, CoCos had 4k RAM standard with 16k an option. The next method to go from 16k to 32k was piggybacking a 2nd set of 16k chips and using some jumper wires. Very kludgey. Next, they made motherboards that were 64k ready, but they'd use "half-bad" 4164 64k chips to get you the promised 32k. By then, the word was out that the CoCo could do the "full" 64k RAM. Probably a good year and a half went by from us modding our CoCos to 64k to Radio Shack acknowledging this and officially offering it in the newer models. If I recall correctly, they NEVER officially acknowledged the original CoCo being capable of 64k. I remember being a teen, going into the local Radio Shack and getting into arguments with the Dude Behind the Counter over whether my CoCo was 64k.

My dad bought me a TRS-89 with the extended color basic in 1986. Back then, I think he paid $75. For my family, that was a major investment back then. It got me started in tech. Wish there were makers around to teach me how to interface to electronics.

They did give you the pin outs for all the built in ports in the manual. That's pretty cool.

I learned BASIC (and Extended BASIC) on my Dad's CoCo (16KB) which he bought from Radio Shack in Miami in 1981. Used it for 4-5 years - probably more than he did. It really did look that bad. I probably ruined my eyes using it. 8 Colours at low res - claimed 64x32 but it was faking it by using special 2x2 "matrix" characters in the 32x16 character display. The extended graphics were only available via Extended Basic, but as the resolution went up, the available colours went down. And no text when displaying "high" res graphics. You should try to hooking up a cassette player/recorder to hear how it saves your programs. Those Joystk ports are for potentiometer joysticks - I still have some of the 2D pots that came from them. For whatever reason, my Dad bought spares which we never used. The most advanced thing I did was a 6809E assembler program that would capture sound samples from one joystk port and play them back in a loop to the TV -- this was several years before sound cards. I plugged an amplifier output directly into the joystk port and did a binary chop algorithm using the Joystick comparator and DAC. The 800kHz machine code speed was enough to capture voice but the 16K filled up very quickly - only short phrases could be recorded. The assembler was EDTASM+ which came on a ROM cartridge.

@igmusicandflying

6 жыл бұрын

I still have my EDTASM on cartridge AND floppy. :) I had the original Coco 1 with "32K" (really 64k) and got the floppy as a high school graduation present. I killed it trying to set it up as a 16k computer not realizing the jumpers changed the power from 5v to 12v. Doh! Young and dumb. :) By that time I replaced it with a Coco 2 which I still have stored. Somebody made a character generator for PMODE 4 ("high" res) that hooked into the BASIC interpreter, so you could run the system in that resolution while working, which gave you mixed case more characters on the display (53x80? IIRC). The later editions could show the lowercase characters on the green screen. I loved that computer.

The Coco was my very first computer back in 1981. I still have a functioning coco-1 and a coco-2. (As functioning as a coco can be now days lol) I remember I ran a BBS on the coco-1 with a big 5MB hard drive!

This was my first 'real' computer. I bought it second hand for $500 with a disc drive and about 150 discs, plus thousands of computer magazines. Mine was cream with wider keys I think, I don't remember my keyboard looking like that, but I'm thinking back 30ish years, I got it in about 1990 I think. I had a brand new Commodore 64 2nd gen, but I had nothing with it, so it got sold and I kept the Tandy. I remember hours sitting there typing out programs from the back of the magazines, then playing the game as long as I possibly could before it was time for the news and Mum wanted to watch the news. Good times. I think back then I actually did more with computers than I do now with all the technology.

I had a COCO for several years, being a tech I did a lots of upgrades to it. First was a cherry keyboard mod, ( I saw one of the early prototypes and it had a regular keyboard on it, later I heard they change it because they wanted hold down the production costs), added 5 programmable function keys, more memory, expansion bay 3 more cartridge slots , 2 ea. 360K Floppy drives, 300 baud modem and a C-itoh printer. I learned a lot about computers and Basic language working with the Color Computer.

I had one of these. I had the 16K version. (There was 8K, 16K & 32K available at the time.) You plugged in a cassette machine to save programs. The games were simplistic, even for the time. Yes - those are the colors, it`s not your hookup. That`s exactly how I remember it looking. I had mine for years. I don`t remember exactly how long. I never upgraded it but I did use it a lot when I had it. I had a couple of the game cartridges (I remember that I discovered a glitch in the football game that allowed me to score a touchdown every time I got the ball). I used some of the programs & had fun altering them. I remember the "music" sound was about the same quality as the color. Thanks for the trip down memory lane.

I had a CoCo 2 with what's referred to as a "melted" keyboard. It was my first experience with programming. I was about 13 or 14 years old and I inherited it from a family friend somewhere in the mid 90s so it was already significantly out of date when I got ahold of it. I didn't get any peripherals with it and that includes the cassette recorder so any programs I wrote were always lost when I powered it off. There were entire weeks on end where I left the thing turned on while I worked on something only to have it eventually lost. That same family friend gave me all sorts of 80s computers including a classic IBM PC AT. Eventually I was able to inherit more modern systems as friends upgraded to the latest and greatest. I finally built my first contemporary system when I was 18, but that CoCo 2 was the first time I ever programmed anything. I learned BASIC entirely on my own and eventually self taught myself VB on some of those later computers I owned. Since then I've programmed in at least a dozen other languages and it's all thanks to that CoCo 2.

First computer I ever programmed on was the original (B&W) TRS 80 - Was like magic. I was about 10 at the time. One of the kids parents at my primary school donated a few to the school (or his company did) (Franklin D Roosevelt primary school - South Africa). First computer I ever saw was at a kids house - think it was a home built one - no idea what it was, but I remember being memorized at the letters showing up the screen when I pressed the keys. I was hooked. Then spent what seemed like years doing paper rounds at 6am to save up to buy a ZX81 (though i suspect my mum put in most of the cash!) .. The rest is history.... :-)

These were incredibly useful machines. We ran a freight brokerage business on this for several years. Modifying a pair of 360K DS drives with a couple of cut traces, diodes and jumpers you could split them into 4 single sided drives that were compatible with the CoCo's disk controller - WOW!! A whopping 1.2M of data, with proper relational database software like ProColor File, was more than enough for our needs. The 32 character, no lowercase display was frequently circumvented with graphic text drivers that supported various word processors, spreadsheets and terminal emulators. Add a Hayes modem and a serial/parallel converter to hook up a decent printer and Bob's your uncle! That chiclet keyboard had to go though, You could order the CoCo2 replacement keyboards later, but my initial solution was to hard-wire a surplus Data General keyboard for the CoCo matrix.

I'd love to get my hands on one of these guys. My first computer (inherited from my dad when I was around 8 or so) is a Tandy 1000HX. Still have it, and I've developed a bit of a soft spot for Tandy as a result.

The shift-0 lower-case mode was useful because you could attach a *printer* that did lower case. (Don't underestimate the value of getting kids more interested in writing papers at school by having them do it on a computer, speaking as a kid at the time :-)

@johnpossum556

6 жыл бұрын

I had the DMP-100 I think it was. Did school reports on it. No true descenders and the thing was so loud I had to wire a telephone cable into a extra long printer extension and put it in the linen closet just to keep the house sane. The thing was like a jack hammer!

@simontay4851

6 жыл бұрын

The old dot matrix printers were very loud.

My first computer was a TRS-80 CoCo 2! I even hacked mine a bit. Had the floppy drive hacked for double sided use. Even learned and used OS-9 (similar to Unix) on the Coco 2. Even though the HiRes (256x192) mode only had 2 colors, you could get 4 colors (as 128x192, but more useful than the hardware produced colors) through artifacting. The VDG could power up on either the rising or falling edge of the clock, so colors could change each time you ran the games. Most CoCo games would start up with a title screen and invited the user to press the reset button until the colors were correct.

Brother thanks for this...OMG...the memories...I had this..all the manuels...and I saved up for the Cassette Player... Oddly enough...I used to get "Programming Books" from RADIOSHACK to make games...However...What I didn't know is that the TAPES used to record the programming needed to be "GOLD or SILVER" top of the line cassettes... I didn't know this..and bought cheap tapes and unfortunately when I'd spend 3-4 programming and Back it up...Nothing backed up...So heart breaking....buuuut...Oddly enough...my career sort've started from this computer...When the computer finally died..my desk became my drawing table....As time moved on...I became a "MOTION DESIGNER"...both talents mixed into one.... So cool..so awesome...I wish I could smell that RadioShack smell again...LOL cheers

Well I have a lot of bt878 cards that could tap the composite at least. Wonder how the power supply compared to the Apple 2.

My first computer. Peek & Poke to turn the Hi-Res screen on. The one had came with 4K of memory...4!..how much more did you need?

Had a coco2, my second computer. My first was a Tandy MC-10, basically the same computer without extended color basic or a card slot. There were a few coco style clones. Clones in the sense that they used the Motorola reference design, the Tano Dragon was the most well known but there were others.

Not sure about specific issues between pal and ntsc. But my Coco looks fine with an rca to coax cable in my modern 32" 1080p Samsung TV. Text is quite crisp, but it's really sensitive to interference

Look pages! Thats my favorite part of a book besides the cover and binding!

I just picked this up from Craigslist and need to find some docs/reviews to see what I can do with it...

One of my first loves. I used one for about 5 years. I had a Floppy drive and printer, so I used it as a school computer when I went to DeVry. OMG, I am such a nerd, LOL

And yes, that's basically the way it looked back in the day, crazy blinking cursor and all - but I think that monitor is doing some weird downsampling which is making those dark borders around the cursor and between coloured areas. I don't remember those.

Nice video Dave. I used all of the Coco's in the series and still have a Coco 2 & a Coco 3. There is still a large following of the machine with a large number of new hardware add-ons. Like SD card support for mass storage and many sound additions. Some people have even taken it to the point of redoing the hardware in FPGA's to add new features.

My first was a 16K Chicklet-keyboard but I still have the 2 or 3 follow-on 64K machines and all the documentation and a couple boxes of Rainbow magazine and Ciarcia's Circuit Celler. Back from the days of being able to understand everything inside the machine. Graphics, Disk contollers...you could fidget with the number of cylinders and sectors on the disk. You could understand it all and goof around with it.

I'm in love with the coco

Oh, the memories! I *think* I started out with 4k, had it expanded to 16k, and then got a third-party 64k conversion. I wrote my own ROM-to-RAM utility so I could hack the "OS". I found a listing somewhere that fully documented exactly what the OS was doing.

OMG. I haven't seen those books in decades! So many RAMs.

Blast from the past. I used to have a TRS-80 home computer in the 80's. Along with a VIC-20, ORIC1, and the good old Spectrum !.

@dj_paultuk7052

6 жыл бұрын

Just remembered, the TRS-80 also was able to run games made for the Dragon32. I think the two were clones of each other.

This is the one that started it all for me. Learning Basic language, buying program books, entering and running a program, then turn it off and start over. Using a little cassette deck to try to store programs, but often failed. I don't remember getting many of the cartridges though? Spent many teen age hours with this (fine?) machine. 🤦‍♂️

The CLS command accepted two arguments. CLS 3,7 From there on you can see why you had the green row of text at the top of the screen (due to CR / LF function). Excellent vid! I had a CO-CO2 in the mid 80's. Wow those were exciting times HAHA!

AT 8:22 you can see that there are extra pads around the bypass caps probably to support different brands.