Wanted: CP/M system

[commodorejohn]

I'm wondering if anyone here has a CP/M system they're willing to let go for something less than eBay price-driver sums of money. Specifically, I'm interested in getting a system that was designed to run CP/M, not one of the assorted home computers that were coerced into doing so with varying degrees of kludgery (i.e. no Apple II expansion card, Commodore 128, TRS-80, etc.) It doesn't necessarily have to be an S-100 system, though that would be cool. Things I'd be looking for:

• 64KB of RAM (more would be cool, but it's not that important.)
• 2+ MHz z80 CPU, or at least the ability to upgrade to one with a reasonable amount of effort.
• 5.25" or 3.5" floppy controller (drives would be nice, but if it's the standard card-edge connector seen in older PCs or the header-pin connector used nowadays, I can supply my own.)
• At least one standard (DB25 or DE9) serial port. (Two if it uses a terminal for I/O.)
• A hard disk isn't necessary, but I wouldn't complain if one were included

Unless it's a system with a built-in or proprietary monitor, I shouldn't need one, as I've got composite and monochrome monitors and a serial terminal on hand, and a CRT would just add to the shipping.

I honestly have no idea what a fair price for such a system would be, since the pricing on eBay is so ridiculous for these kinds of machines, so make me what you feel is a reasonable offer.

 

[ahm]

You might have enjoyed this Sony SMC-70. http://search.ebay.com/140453685372

Andy

 

[GADFRAN]

Check out Kaypros - various models - some even have HD - many CP/M - different versions.

Cost - free, shipping, local pickup, etc.

Search this site and do a post - many available + lot of help on this site to make sure it works !

Good luck !

Please keep us posted as to your results for our Kaypro Knowledge Base on this site.

Frank

 

[Chuck(G)]

Remember that CP/M-86 was offered for the IBM PC as well.

It depends upon what you're after. If you're trying to get the CP/M "experience", then CP/M-86 is a quick and dirty way to get it. If you have CP/M-80 code that you need to run, there are scads of systems out there, all different (like the the twisty passages) and facilities vary according to year. For example, the Amstrad PCW was a fairly late CP/M 3.0-based system wth memory-mapped graphics (the system actually has no text mode). Earlier systems are text-only and not all are memory-mapped.

Storage can vary from a 90K single-density floppy to systems with hard drives. Communications (e.g. serial ports) can vary from none to rather elaborate multi-port setups. Some CP/M systems even used multiple CPUs. There was even some primitive networking on some.

 

[commodorejohn]

Check out Kaypros - various models - some even have HD - many CP/M - different versions.

Cost - free, shipping, local pickup, etc.

That would definitely be one option; actually, there was a Kaypro II on eBay that I just missed bidding on that ended up going for ~$50 + S/H - rather astonishing when most of the Kaypros there are priced at $400+! Ah well. Still, while that would work, I'd kind of enjoy having a desktop machine rather than a luggable.

It depends upon what you're after. If you're trying to get the CP/M "experience", then CP/M-86 is a quick and dirty way to get it. If you have CP/M-80 code that you need to run, there are scads of systems out there, all different (like the the twisty passages) and facilities vary according to year.

True. For the record, what I'm after here is less the operating-system "experience," as I can set up SIMH's Altair emulator quite easily for that purpose. I'm more looking for an interesting older work/business micro from the late '70s-mid '80s to tinker with. I'm not really looking for a graphical system, although I don't have a particular aversion to using one. Storage-wise, I'd like to be able to use higher-capacity disks (360KB 5.25" or up,) since I have a boatload of them sitting around waiting to be put to use.

 

[Chuck(G)]

I'm more looking for an interesting older work/business micro from the late '70s-mid '80s to tinker with. I'm not really looking for a graphical system, although I don't have a particular aversion to using one. Storage-wise, I'd like to be able to use higher-capacity disks (360KB 5.25" or up,) since I have a boatload of them sitting around waiting to be put to use.

Well, there was business and then there was business. I'd consider the Kaypros, Osbornes, etc. to be "personal" and not business computers.

An 8-bit business computer to me would be a Molecular Supermicro 64 - 64 Z80A CPUs. To be sure, there were single-CPU systems aimed at the business customer, such as the Televideo TS-8xx series (some of them could network). Altos intended its boxes as business systems and certainly Bill Godbout's Compupro line was aimed in that direction. Likewise for the Xerox 820 line.

While CP/M was prevalent, there were many other operating systems with significantly more capabilities. There were also CP/M systems in embedded applications, such as CNC.

 

[commodorejohn]

Okay then, rather than "business" we'll just say something like I outlined in the initial post, a CP/M-oriented Z80-based personal computer along the lines of the Kaypros or later S-100 systems. (64 Z80s? Really? Good lord.)

 

[Lord Moz]

Any particular reason you are excluding the C128?

It was designed to run CP/M, and is likely one of, if not the most advanced(latest graphics/sound anyway, no concurrent multi-cpu stuff,etc) CP/M system made. Nearly full compatibility with Kaypro software & several other popular systems, plus several additional features. Commodore made a 3.5" drive for it, and 3rd parties made HDs & plenty of other addons. It has fairly well developed graphics & sound capabilities, perhaps the best of any CP/M system. Many of these features were not used much, but could be fun to explore & develop new software for. The C128D is my preferred machine, as it is much easier to work with its detached keyboard & stacked monitor (I run mine on a Tandy CM-11 CGA monitor).

Just wondering why you were specifically excluding one of my favorite CP/M machines (the other being the Kaypro 10)
__
Trevor

 

[Chuck(G)]

Trev, the problem is that the C128 was never marketed as a serious CP/M machine--it was just mentioned in passing, it seems.

The biggest liability is that it runs the Z80 at about half-speed (2MHz) because of memory contention with the video chip. This, in 1983, when not only the IBM PC made its appearance, but also when everyone else with a Z80 box was running it at 4MHz. The other problem was that you needed a 1571 external drive.

And most people who bought the C128 considered it to be a souped-up C64. I have C128 CP/M floppies in my library, but I'm not aware of any business that considered the C128 to be a serious CP/M system.

A shame, because there was some clever engineering there.

The Apple II could be equipped with a card to run CP/M also. But that's not why people bought the machine.

 

[NobodyIsHere]

Hi! You could build your own Z80 CP/M computer with the N8VEM home brew computing project. They are inexpensive and fun to build. There are three SBCs you can choose from; the SBC V2 (Z80), SBC-188 (80C188), and 6809 (CUBIX). All of the SBCs have more than 64K RAM -- the SBC V2 has 512KB.

With the ECB backplane (in redesign at the moment), you can add DiskIO for various floppy drives and IDE hard drives. The SBC includes serial, parallel, RTC, etc but if you want more there is a Zilog Peripherals board that adds DART dual serial, dual PIO (quad parallel), and CTC for timer/RTC. There are several ways to add video such as the VDU for plain composite text, PropIO for VGA compatible text, and SCG for sprites/color graphics and sound (TMS9918, AY-3-8910).

In addition there are several other boards you can make easily to do various other things. The N8VEM project is most ECB centered although we are nearing the release of a completely open/free (as in speech) S-100 system which has similar capability.

What's nice is it makes the hobby enjoyable to make your own system while keeping the costs low. The system can be built up incrementally to avoid the large costs up front. I have all the PCBs on hand so you just build them yourself. There are instructions on the wiki or you can ask the other builders on the mailing list. Good luck with your search!

Thanks and have a nice day!

Andrew Lynch

 

[Lord Moz]

Yea, I'm aware of the issue with the Z80 having to wait for the video. I remember reading that there had been some evidence that Commodore had tried to implement a "fast" mode where they could turn off the video chip and "unchain" the Z80, but they couldn't get it to work. Is that something that will never be possible, or maybe something that could be figured out, 25 years later?

And I guess I figured most people with a C128 would have a 1751, but I notice from CommodoreJohn's signature that he doesn't. If one acquires the C128D, that problem at least is solved I just JiffyDos'd mine

Anyway, I know its CP/M capability wasn't ever really marketed much, but the machines they chose to emulate were very popular, so finding software to run is pretty easy.
I need to get mine working with my 1581 though. Then I'd have tons more space and my only CP/M system with 3.5" disks

Ok... off to PT for me, then to sleep again... spent all night putting insulation above the garage Moving empty boxes from my eBay acquisititions took most of the time lol
__
Trevor

 

[kb2syd]

And the TRS-80 models 4 and 4p were great CP/M machines. So were the models II and 12. I like CP/M on the 4p.

 

[commodorejohn]

Any particular reason you are excluding the C128?

ChuckG said it already, but the big problem with CP/M on the 128 is that it's limited by the Z80 (and the 80-column VDC) being rather awkwardly kludged onto the design at the behest of Commodore management (designer Bil Herd has written an extensive and hilarious article about the travails involved.) 2MHz is a respectable clock speed for the 6502, but not the Z80. (There's also the problem of the supplied BIOS for 128 CP/M being incredibly slow, but third parties have remedied that.)

I need to get mine working with my 1581 though. Then I'd have tons more space and my only CP/M system with 3.5" disks

There's a 1581 disk image for CP/M you can get, and Bo Zimmerman's Commodore FTP archive has the improved BIOS and ZP/M, a generally improved version of 128 CP/M. Takes a bit of work to get it on a disk, but it definitely improves the experience.

Hi! You could build your own Z80 CP/M computer with the N8VEM home brew computing project. They are inexpensive and fun to build.

Yeah, I've considered this before and may do so in the future, but that's not really what I'm looking for here; at the moment I'm more interested in finding an old-school system rather than building a new one.

 

[Chuck(G)]

Andrew's got a great suggestion if you want to "roll your own". The TRS-80 systems (except for the Model I (ROM address issues) were all capable of running CP/M and disk images are widely available and, especially the Model II and 16 were serious business machines.

If shipping is an issue, any of the big boxes, such as the TRS-80 are going to be a problem. Another possibility are some of the single-board systems, such as the Ampro, where all you need to do is add a power supply, drives and a terminal.

There were also plug-in boards for the IBM PC for the sole purpose of running CP/M.

The choices are many...

 

[glitch]

Keep watching on eBay for a Kaypro II. I picked mine up for $16.something, excluding shipping. They're not that rare, and if you wait long enough, you're likely to find one for a very reasonable price. I like mine, and still use it to process text and write 8080 Assembly programs. You'll enjoy having double-sided drives if you can find one configured with them, though!

 

[billdeg]

And the TRS-80 models 4 and 4p were great CP/M machines. So were the models II and 12. I like CP/M on the 4p.

That was going to be my suggestion as well. A Model 4 is perfect for what you seem to be looking to do.
bd

 

[NobodyIsHere]

There were also plug-in boards for the IBM PC for the sole purpose of running CP/M.

Hi Chuck, speaking of which, have you ever seen a CP/M distribution for the Xedex Baby Blue CP/M Z80 board for the IBM PC? That would be a good choice if someone wanted to reuse an old PC. I have a Baby Blue board but the software lets you run CP/M applications but not CP/M itself. Seems odd to me.

Thanks and have a nice day!

Andrew Lynch

 

[Chuck(G)]

Hi Chuck, speaking of which, have you ever seen a CP/M distribution for the Xedex Baby Blue CP/M Z80 board for the IBM PC? That would be a good choice if someone wanted to reuse an old PC. I have a Baby Blue board but the software lets you run CP/M applications but not CP/M itself. Seems odd to me.

Hi Andrew,

No, sorry, I don't have anything for the Baby Blue.

But it's not odd at all, if you consider the attitude at the time (1980s). CP/M boxes were still being sold in parallel with the 5150, so it's not as if they were scarce. Most of the major CP/M software producers brought out PC versions of their leading products, but for those people moving to he PC, there was the problem of what to do about legacy applications that weren't available in DOS versions. Consider that many small businesses used CP/M systems for general business applications (AR, AP, GL, payroll, inventory) and had invested in training for them. What customers wanted was a way to run their old applications on the new PC hardware--and if the applications could be seamlessly integrated into a PC DOS environment, so much the better. CP/M itself held veritually no interest to the customer.

I have a good friend who (at last check) uses MicroPro Datastar to manage his contact list--on Windows XP. Datastar, to the best of my knowledge, was not a success in the 8 bit world and MicroPro never bothered to 'port it to the DOS world.

From the vendor's standpoint, MS-DOS was very close to CP/M in terms of interface, so it made little sense to license CP/M.

 

[Pound33]

I have an old Molecular Supermicro 8 that I bought new and now need to get rid of, and would like to see it go to a good home rather than to that great 80s office in the sky. 10 MB Winchester hard disk, 8" floppy drive. Still have the terminal, serial printer, and original software on 8" floppy disks (what are the chances that the floppys still work?). Last time I tried to fire it up it wouldn't start. If anyone is interested, please let me know. Dumb as it sounds, the thing has some sentimental value to me.

 

[Klee]

I have an old Molecular Supermicro 8 that I bought new and now need to get rid of, and would like to see it go to a good home rather than to that great 80s office in the sky. 10 MB Winchester hard disk, 8" floppy drive. Still have the terminal, serial printer, and original software on 8" floppy disks (what are the chances that the floppys still work?). Last time I tried to fire it up it wouldn't start. If anyone is interested, please let me know. Dumb as it sounds, the thing has some sentimental value to me.

Location?