I would imagine the memory upgrade is probably working correctly and the reason you're only seeing around 60k is because the rest of the memory is most likely bank switched and can only be seen by applications written to use it. You could always look and see if there's some sort of memory test for other CP/M machines that can test higher than the 64k limit. (Probably would require modifying memory addresses in the source of the application to work with the Kaypro's memory layout since there wasn't a lot of standardization amongst CP/M machines)

@johncate9541

2 жыл бұрын

That was my thought as well. Bank-switching was done by all sorts of software in those days. It was what kept the Apple II alive for as long as it was. And this Kaypro was never designed to be used with more RAM than it shipped with. Everyone who used CP/M heavily customized it to their own system. I doubt it would even know to count past 64K even if it could detect the homebrew upgrade card.

@paulstubbs7678

Жыл бұрын

The Z80 can only address 64K, it only has 16 address lines, so anything beyond 64K is a kludge. If they copied another machines above 64K designs, then you could hopefully use their software to control it, otherwise your on your own to write your own code to drive your board. You would probably have to hack most CPM software to use it, as that code uses the standard 8080/Z80 instruction set, that only does 64K

You know, I've seen more of the back of my head on your channel than I have in the rest of my life. That's probably a metaphor for something. I want to see that Kaypro at the next VCF as part of "ActionRetro's cursed computer collection"

In future: you can remove the entire drive sled by removing four screws on the bottom of the chassis. That way, you won't have to remove the logic board to futz with drives.

@hicknopunk

2 жыл бұрын

Yes

@garthhowe297

2 жыл бұрын

Fantastic...I have one arriving next week, and this info will save me time.

Thoughts: -If the card ever worked at all (a good chance as the previous owner was smart enough to hack in a HDD) those burned wires and caps may well point to a fried IC or several on the board too - happily they look to be socketed and are probably available today. -Fried wires suggest a short at some point, one assumes temporary as the computer boots. Best look at that rat's nest very carefully for any sign that something has come loose or is in danger of touching something it shouldn't once more. -The codes on the IC's will give an excellent indication as to what the board is actually for. If I had to make a wild guess it's RAM for an additional RAM disc and that "Initialise?" question on boot is to run a 'driver' for the board - it does nothing because the board does nothing, either being broken or requiring specific commands to address it. Given how few IC's there are, and the fact that the computer both works at all and doesn't report any extra RAM I'd be surprised if it's a system memory upgrade but you never know - remember 8it CPU's can only address 64k without bank switching hardware and the reported system RAM would seem about right for a 64K CP/M machine that's running a basic system and a few 'drivers'. -A quick google should turn up a treasure trove of CP/M programs, including system diagnostics which may give you a further clue - be advised, while CP/M was pretty much the first 'universal' OS that really only applies to software running on the OS - any 'fancy' hardware will need 'drivers' and storage formats were generally specific to specific machines - if not a Kaypro disc image it probably won't load when transferred to a floppy. Your 'modem' may come in handy as often once you've sidestepped proprietary storage formats via a terminal emulator you can resave to your own discs. -As an aside you should be able to find some Kaypro utilities discs to allow this machine to read disc formats for selected other CP/M machines. Failing that the Commodore C=128's CP/M of all things has such utilities should you have access to one of those! -I'd be willing to bet that upgrade will have been a DIY project published in an electronics magazine rather than something the previous owner designed. So a bit of googling for DIY Kaypro upgrades may give you a clue... possibly for the HDD hack too... and maybe some DIY projects of your own. I hope that helps a bit.

@KerfusVoTV

2 жыл бұрын

Loong looong maaaaaaaaaaaaaaaaaaaaaaaaaaaaaan

@medes5597

Жыл бұрын

Wasn't kaypros big gimmick that it could read literally any disk format? That's why it was so popular with business people?

@JeffreyPiatt

Жыл бұрын

No there gimmick was being portable and being built like tanks. What killed them was sticking with the Z-80 for too long and not moving fast enough to IBM compatible. Basically the Compaq Portable killed them off.

4:02 This confirms the terrifying click is what I thought it was. It's hard to tell if you haven't seen it in person because on the video it just sounds like the switch being flicked two times.

The initialize question upon boot is asking if you want to initialize the RAM Disk. It would make sense that the RAM was hacked to increase it's size if a RAM disk was regularly being used in CPM

Definitely enjoy non-Apple videos alongside the Apple shenaningans. The Z-80 CPU in the Kaypro can only directly access 64K of RAM, like most 8-bit processors. So if the added circuit board is a memory expansion board of some sort, the memory will almost certainly only be switched into the processor's address space a few kilobytes at a time. This likely would have been used as a RAM disk, or expanded memory that only specially written programs could have used. If used as a RAM disk, it would require a driver to be loaded from the hard drive. You might look around on the drive and see if there's any plausible program. A RAM disk would have made the memory show up as a drive letter. Could the 'Initialize' message at boot be from a RAM disk driver asking if you want to initialize (format) the RAM disk? In this case, I would expect that there should be an extra drive letter hanging out in there that would show an empty directory after boot.

@ulrichkalber9039

2 жыл бұрын

so try to change to d: e: etc. ?

@dougmccomber

2 жыл бұрын

No doubt that is what “initialize” is referring to. You nailed it!

The memory above the 64k that the Z80 addresses is paged. There were various hardware hacks in magazines at the time. The 8088 from intel put a paging system on the cpu chip as part of an upgraded 8080 and clone of parts the Z80. MSDOS was originally an upgraded CPM clone that handled the paging transparently to the user. The Kaypro 10 used a Western Digital floppy/hard drive controller board instead of control chips on the main board as on the Kaypro II.

those 192.168 IP addresses are local IP addresses and only apply to your specific local network, they're useless to anyone who isn't on your wifi so no need to worry about them much

@SectorfiveYT

Жыл бұрын

Yeah I was thinking that too, he might not be that tech savvy to understand the difference between local and a public ip address, but life and different intrests take us to different pathes in life so we don't all learn the same things or are interested in them.

CP/M (at least on many machines) doesn’t detect memory automatically. You need to use MOVCPM and SYSGEN to regenerate the boot disk configured for the correct amount of memory. I don’t see MOVCPM in your directory listings so maybe Kaypro did away with that somehow (or didn’t anticipate a need for a different size CP/M).

@bobdole57

2 жыл бұрын

I believe all z80 Kaypros were sold in a 64k configuration.

@martindejong3974

2 жыл бұрын

@@bobdole57 Meaning they had 64K ram inside, NOT that they could support a TPA (transient program area) of 64K. Most of them had "holes" in the upper memory to support stuff like "video ram", and perhaps a keyboard matrix, although this more likely were I/O mapped not memory mapped. AFAIK no CP/M machine used virtual memory, although some supported swapping out the video RAM to enlarge the TPA. Perhaps this is what the patch board did? you said the previous user replaced the RAM chips inside with larger (capacity) versions? so what chips did he used?Normally many 64K systems of that time would use four banks of eight 4116 (16K bit per chip) RAM's for a full 64K, but a Kaypro would probably already use these chips, or perhaps they used just eight 4164 chips for 64K RAM.

@bobdole57

2 жыл бұрын

@@martindejong3974 I was just trying to say a given model will always have the same memory map and you don't need to reconfigure cpm if you are using the master disk that came with it. As opposed to say an s100 machine which could have 8k to 64k with memory cards

@editorjuno

2 жыл бұрын

Kaypro's implementation of MOVCPM was notoriously broken, so perhaps they wisely left it out of their later software bundles. IIRC, it relocated the CCP and BDOS segments correctly, but failed to do so for the BIOS and therefore a boot disk created with it would not work.

Oh yes, more vintage computer shenanigans please! Mac or not.

Great video, and I'm also one who loves the non Apple stuff, as I don't think stuff like this Kaypro get spotlighted enough in the retro community. 👍

"So Be It" lol. If only it could say....."So let it be Written, So let it be done!" All computers need a little Yul Brynner Flavor to them 😄

Hey man I’ve got a pitch for you NetBSD has ports for 68k macs and nextstep machines and also window managers that look like both in its repo Might make a fun video

These Kaypro videos are why I subscribed. I have a Kaypro 10 I am learning about. It has a very interesting musical history as a programmer for the Synergy synthesizer used by Wendy Carlos of Tron, The Shining, and A Clockwork Orange fame. This is wonderful content. I look forward to more.

This was great, would love to see more Kaypro stuff in the future - and any CP/M in general. I got into computers a little late for CP/M so this is fascinating and new to me!

Yes! More shenanigans please! Very interesting series. . .

The Kaypro you booted first runs a modified CP/M. There is a file "ZCPR" there. That stands for "Z Command Processor Replacement". Also known as the Z-System, this was a custom extension for CP/M that added lots of quality of life features. The "Initialize?" prompt is there to format a RAM disk on bootup.

Loved this, I have a 4 arriving next week, so all info is helpful

Most CP/M software was written to assume no more than 64K. I would suggest you check what’s in your hard drive and then google to see what can recognize more memory, and then try running it. That will hopefully tell you if the bank switching is functioning. As someone else mentioned, if the caps and wire are fried, check/change the chips too.

Man I wanted a Kaypro sooooo bad back in the day. It was going to be the foundation of my CP/M software empire. Sigh......

Excellent video and work!! Apple and non Apple videos are fun! Kaypro is really neat!! Thanks for sharing

I also have a KayPro 2 and a KayPro 4 in my collection - cool to see someone else with the same pairing! Love the video - please keep 'em coming!

This is such a cool custom mod. I would personally love to see you reverse-engineer the modification and make a new modern PCB with it, not only to preserve the original modification; not only to create the definitive final form of the original designer's vision -- but also to allow others to perform this modification as well. Doing so would also improve the reliability of the modification and maybe even allow for more functions to be added. As an additional point-of-thought: perhaps the initialization command has something to do with the expansion board. Perhaps it requires one to initialize after first boot, then press "RESET" for the machine to detect the RAM upgrade on subsequent boots, prompting the relocation of the "RESET" button for greater convenience. I know you already tried it, but I think it's a combination of both this and another potential failure on the machine itself.

I am old enough to remember how 2400 bps felt! This is pretty awesome though. Just connect to your local Linux workstation and run links (or lynx for gopher support) and read Wikipedia, perfection right there my dude.

@borgheses

Жыл бұрын

i am 42 and connected for the first time at 2400bps on an 8088

I like these modified machines so much more than perfect stock ones, this one has a history. I tend to look for handhelds and consoles that have had screen mods or old modchips, it's just fun because it's mods you can't even get anymore.

been loving these videos! 🥰

I do like these old computer shenanigans your up to and would like to see more. And have you made a specific vid on those mod games or what ya call em?

I grew up using a Kaypro 2. I love seeing videos about the tech I was too young to understand back then! It's also fitting that I watched the 2 videos about the kaypro today, as there was one "featured" in the second episode of stranger things season 4 that came out today. you'd be hard pressed to recognize it if you weren't looking for it though, as it was shown having a 2 color screen, and actual non ascii graphics. but if you pause at the right time you can see "kay" at the top left of the keyboard.

I don't think that the Kaypro will ever report more than 64K. The Z80 has a 16-bit address bus and only takes 2 bytes for addresses - it can't "see" more than 64K at a time and would require some bank switching scheme to handle more. BTW, I think, this custom board may be about a RAM-disk. Mind that the (modified) OS reports "RAMDRIVE" at boot, just before the prompt "INITIALIZE?" comes up, which is probably asking for whether to initilize this "RAM drive" or not. (Is there / has there been any battery connection for backup?) It could even be that this somehow buffers/shadows the hardware floppy drive, which may be causing the latter to appear not to be working properly, but I do not suppose this to be actually the case. Anyway, a RAM disk would make much more sense for a heavy duty machine than a non-standard RAM expansion, which could be used only by some specially made software. (Bank switching would probably require some common RAM space, in order to work seemlessly. You could look for a respective wiring scheme regarding the address bus, to verify.) Standard software, on the other hand, that requires more than the full 64K complement would probably use segment overlays loaded from disk and would benefit from a RAM disk out of the box. Edit: I 'd suggest to look up this "INITIALIZE" prompt in ROM and what this triggers. This will probably tell you what that board is all about.

Does "Initialize (Y/N)" create the ramdisk maybe?

0:52 - My Amiga: “I died. Why was I resurrected after a decade?” Me: “Because I wasn't alive when you were on the market and I *want* you. I won't throw you off of a table like the last guy who had you, I promise.”

I Like that you exploring BBS with a Modern Wi-Fi could have been exciting. 😇👍🏻💙

The extra ram might be what it being used for the ramdisk during every boot, I find it hard to imagine a scenario where you'd wanna take memory away from a 64k stack for a ramdisk when you have a fixed disk present.

@hicknopunk

2 жыл бұрын

My mac+ with 1 meg, I would use up to 380k as a ramdisk for system files even though I had a 400 meg hdd. It really made things faster/better when dual tasking music works and hypercard.

@dungeonseeker3087

2 жыл бұрын

@@hicknopunk Sure, you can take 380k from a 1mb stack, it gives you a useable and useful space and 620k left for the system. Taking anything out of 64k though has the opposite affect, you cant take any meaningful amount of space without also leaving the system with nothing.

@hicknopunk

2 жыл бұрын

@@dungeonseeker3087 I was a small child when I used the Kaypro 2 we had, so I don't really know what is a critical amount of ram for that cpm.

@dungeonseeker3087

2 жыл бұрын

@@hicknopunk Fair enough, TBH neither do I. I just don't see how taking anything out of 64k is worth it when you have a 40mb fixed disc to use. If I had to guess (though it is a guess) I'd say the ramdisk was probably to store programs while running them since it would be faster than doing so from a spinning drive. I guess the question is just how big is a typical app for the kaypro?

@hicknopunk

2 жыл бұрын

@@dungeonseeker3087 hmmmm, yeah. I am not sure. I would arbitrarily guess the os would take about...8k of ram. The video hardware seems to have 10k of total ram. Hopefully games only take about 40k to load. Again, I am utterly guessing.

Regarding the missing characters when using the serial link, that is usually an indication of an issue with flow control.

Looking forward to a video on repairing that floppy drive. I’ve got the same model Kaypro and both drives are “cursed” and need fixing.

Regarding the memory, the maxim memory visible to most CP/M versions is usually 64K minus some small amount for the OS kernel, since the Z80 CPU can only address a 64k memory space, and most versions of CP/M do not support memory beyond that amount. To see additional memory, you either need to run CP/M version 3.0 or later, or address the additional memory as a RAM disk.

That IP is local not public. Unless someone is one your wifi it would be useless for anyone to know

I might have relocated reset buttons before. I used to hate working on laptops because there wasn't a reset button. ;) That's one thing I like my old iBook for. You need a bent paperclip to push its reset button, but at least you don't have to hold it down for _x_ seconds.

I have four kaypros. My favorite is the 4+88 which can run cp/m, msdos and cp/m86 as it has a co-power 88 board factory fitted by kaypro. I have an original kaypro 2 with full height single sided drives, a new 2, and the fours. As an interesting aside, the commodore c128 cp/m hardware was designed to be able to run kaypro cp/m applications with little to no alteration. The c128 runs them at about half the speed of a kaypro though.

With those mods, I'd design a custom PCB to make it way nicer and hopefully keep it working for longer.

I'm also in the group that doesn't mind non apple shenanigans. Not that I dislike the apple shenanigans, but the variety is nice.

CP/M problem was that every CP/M machine has it own format, even on different models of the same company machines. The Kaypro 2's disk format is different from the Kaypro 4, thus disks formatted on the Kaypro 2 are unreadable on the Kaypro 4 and vice versa. This is despite that the CP/M software was compatible to all Z80 based machines across the board. If all CP/M machines were using the same disk format like the IBM PCs and their compatibles, CP/M machines would have the the standard and not the IBM PCs.

These videos are grand! There's unfortunately only so much to explore in PowerMac-land.

LOOOVE IT!!!!

That's not duck tape, it's gaffer tape, and you're lucky it left so little of the usual white powdery mess it is known for. It's usually much, much worse after this much time.

@kaitlyn__L

Жыл бұрын

Gaffer tape is the generic name for Duck brand tape. Or so my brother told me after he worked as a roadie for the Water Buoys.

@mal2ksc

Жыл бұрын

@@kaitlyn__L Your brother is in error, but you are right that Duck is a brand, not just one specific type of tape. The silvery, rubbery, and not very tough tape (but very sticky) is what's usually associated with Duck, I think it was their original product. It is far inferior to gaffer tape except that gaffer tape is not completely watertight or airtight since it has no rubbery coating.

oh man i remember the days of trying to solder stuff on wire-wrap board. That was FUN......

10:28 Perfect spot for a sponsor plug and i'd've been disapointed had you not put it there given the perfboard discovery at 10:10

Could also be a disk doubler circuit. Original Kaypros were SSSD with different drive and disk doubler you can get DSDD disks. Old Kaypro 2 user myself

Seeing under the tape is such a cool payoff

Make sure the modem and term are set for proper handshaking either software flow control or hardware flow control.

Yeah, I posted something that I found about the original owner of your Kaypro on your discord server, but people weren't too welcoming... I think I was misunderstood. Well, anyway, thanks for your videos, I really like them!

Wow… that thing is a genuine artifact grade item IRL

Let's hope the Kaypro's curse doesn't spead online lol

they are bypass caps, they don't do anything that would effect the operation of the memory card!

this is my favorite machine on the channel

I would love to see a video of making pcb for that homemade addon card

Something about briefly putting hte floppy on the keyboard only for the floppy to slide down cracked me up. I have a visceral memories of that exact thing happening many times as a child.

Well, I know very little about CP/M, but does it have an equivalent to config.sys where you can look for files being loaded in and try to spot something that looks like a memory driver or ramdisk driver? Does the HDD contain any files that could suggest such drivers? Well, that is the extent of my knowledge, great video, and fun to see it on the internet!

@editorjuno

2 жыл бұрын

No. MS-DOS's (eventual) implementation of device drivers in the form of .SYS files was a big advance in that respect. Any additional code for hard drive access would required modifying the vendor-specific BIOS segment of CP/M.

I will be getting a Kaypro soon.

But what if the RAM amount is a tad less, because the HDD systems needs a little bit of space to kickstart its bootloader?

@editorjuno

2 жыл бұрын

Bullseye. These young'uns don't know nuthin'! :-)

More non-Mac.stuff in the future would be great!

Hey man, nice baud

Wow, way cool !!

I believe that's not a memory upgrade, it's a RAM Disk. That is why it is asking if you want to initialize it on boot. How does CP/M handle that? As another "drive"?

8 bit CP/M systems can only ever see 64K of RAM as system memory. Systems with more RAM than that used bank switching to take a "bank" of the expansion RAM at a time (typically between 4K and 16K) and "switch" it into part of the 64K memory space. The bank of memory selected would commonly be set using an OUT instruction to a register mapped to an I/O port of the Z80. This was too complicated for CP/M programs to deal with and there weren't standard BDOS calls to make it easy. However the bank switching scheme kind of fit how drives operate with sectors so CP/M treated ram expansion as disks. On my Coleco ADAM which was about the same vintage as the Kaypro 4 you could get a 64K RAM expansion and when you booted CP/M with one installed a drive M: would become available automatically. On the Kaypro it appears to ask you to initialize it manually on boot. On the ADAM the command "STAT M:" would report how much RAM disk was free. The Kaypro probably does the same thing if that home made board is indeed expansion RAM, though it may use a different letter like D: (the next available letter after the floppy) or R: for RAM? Anyways maybe press Y to initialize then try different drive letters to see if they appear to work as RAM disks! I usually copied programs onto M: because they loaded WAY faster from there, and RAM disks would retain contents across warm boots (though cold boots and powering off erased them) so it was like a primitive form of task switching. Fun fact: the Coleco ADAM is based on the Colecovision video game system so it has a game cartridge slot. Besides Colecovision games Coleco was planning to make cartridge versions of CP/M programs like Wordstar but they discontinued the ADAM and went bankrupt before that happened. However if a cartridge was present ADAM CP/M could dump its contents into the RAM disk on boot, so you could "rip" game cartridges to floppy disks (5 to 10 games fit on one floppy), and some homebrew cartridges of CP/M programs have been made too and they load super fast! RAM disks can be fun!

I remember my first modem. It was a 300/75 baud speed monster. Yep, that's 75 baud upload speed.

@hicknopunk

2 жыл бұрын

The first one I bought with my own $$ was a 1200 baud download. No idea what the upload was.

@editorjuno

2 жыл бұрын

The Kaypro 4/84 has a built-in 300 baud modem.

Did you buy that TheOldNet WIFI modem or build it? Apparently there is only one open node on port 6502!

I assumed you were somewhere around PA / NJ. How else would you have a South Fellini shirt of North Philly!

Mate I had a 2400baud modem, always dreamt of have 56k one back in the day!!

@markvickroy6725

Жыл бұрын

I still remember getting my first 14.4k

If you want, i can happily make a new one of those upgrade boards using Sprint Layout :)

Copying that disk I loved the Twilight Zone rotating black & white cone/ bullseye pattern. Now in some true TZ craziness it happens I'm re-watching the original show and was smack-dab in the intro right then with it too showing nearly the same pattern... Rod Serling, is that you??? 😂

It seems kind of self evident to me, but CP/M isn't going to magically find the extra memory, it's not programed for that. You likely need custom programs that will try to address that extra memory if you want to use it. You should test the chips though to make sure. Also the spinning drive is a good sign, means the belts are good. So it's probably just "broken" because the read heads are dirty. Clean them off with some IPA and call it good.

I’d imagine a decent logic analyzer would show what that memory expansion is doing if anything at all. I’d imagine anything over 640k would only be addressable to only applications aware of it since cpm is very similar to dos.

@editorjuno

2 жыл бұрын

Try 64k. It takes a 16-bit CPU to directly access more than that.

Is the expansion just for the RAM Disk?

Cool AF. Speaking of HTML, I was watching Stranger Things SE4E7 last night and there is a scene where they are trying to find the 'GPS' location of Eleven. One of the actresses (yeah I said actress - triggger warning) was using an old PC to connect with a modem to another node. When it connects the response is in HTML format. In 1986. Righty-ho then.

21:30 I am near certain the UART in the kaypro is capable of 2400 baud. It's been a long time, but I am pretty sure the early ones (this computer was made in 83 or 84) are all capable of 9600 baud. If 2400 were too fast, nothing would work. What is likely happening is the buffer is filling faster than can be displayed. Try a different terminal program. Or see if you can increase the buffer size. Also, don't rule out the buffer of the adapter you are using.

A Z80 cannot address more than 64K memory. The extra memory can be used for example a ramdisk. I have a Bondwell 14 with 128K of memory. (63k ramdisk) Was a Bondwell 12 (64k) but i have put the 128k myself... + a rom disk yep a romdisk. Some cp/m utils i have put in eprom.

Ductape held better than computer itself - to recycling center it goes.

that 192.168.x.x IP is for reserved local LAN use only, it would never work on the forward facing internet via your WAN! Sheesh...

Maybe fellow KZreadr The Tech Timetraveller can give you some hints with the breadboard. He appears to love playing around with computers that require hand soldered futzing.

yea i like when its not just apple machines. the older and weirder the better :)

So if it boots _off of_ that hacked-in hard disk, then what does it boot FROM?

You absolutely could not walk a letter faster than 300 baud. I know you said it for comic effect, but I don't think you realize what a breakthrough that was. Whereas before, you had get dressed, get in a car or take a bus to the place with the computer, fill out a form, wait for some clerk to get you what you needed and pay a fee and then drive or take a bus home. AFTER modems, you could access it yourself in your underwear from your bedroom , even if only at 300 baud. It FEELS slow, but is WAY faster than driving or the bus.

luggable!! the word is luggable!!

Great!

The new season of stranger things, Murray is using a kaypro trace a phone call.

I was surprised you didn't call the event #CPMay, for all things CP/M.

Can't wait for JuliMac.

@okona1up

2 жыл бұрын

Wouldn't that be Marchintosh? (-:

Kursed Kaypro 2: Internet Boogaloo

Make a new pcb memory board for the kaypro

Why not connect this device to a Raspberry Pi running a Linux Getty Terminal, and then you can run Lynx, or Alpine in a screen instance?

I think those wires could use some HOT-GLUE... a whole bunch of it.

If you're using flux when desoldering capacitors, doesn't it mean that they're now... flux capacitors? 🤔

@TheRetroRoadshow

Жыл бұрын

"When this baby hits 8.8MHz, you're going to see some serious shit!"

YESSS MOAARRR PA Tubers! :)

Give Adrians Basement a shout!

I was waiting to see ROBCO industries on the screen.

Sound like something in the wheelhouse of Adrian’s Digital Basement

It’s a 192 IP address so doesn’t matter if you change it or not. That is the private network IP

i just like how pretty you recorded this video