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What is the best CP/M machine and why?

JonB

JonB

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I seem to be getting very interested in CP/M and I'm wondering which is the best retro computer to run it on.

My parameters for "best" are performance, interfaces, hard drive availability, floppy size, keyboard quality, screen quality and graphical capability (not too important that one!)

I have a few already: TRS80 Model 4, amstrad 6128 and 8512, Tatung Einstein and Memotech MTX512. Of these, only the TRS 80 and the Memotech have hard drives (both implemented with modern flash memory).

None of them seem to fit the bill (although I do like the Model4).

What should I look out for, and why?
 
I'd be interested to know why you don't think the Model 4 fits the bill? Or is it that you just want a few more choices.

The Epson QX-10 is a lovely CP/M machine, although I'm not sure if hard drive implementation is easy.

Tez
 
If it weren't for the lack of RS-232 port, I'd say Commodore 128DCR.

The Coleco ADAM is an oft-overlooked option, and it's my favorite, if only because I can also play ColecoVision games on it too. ;) You do need a few bits and bobs to make it more palatable as out of the box it only does 32/40 column modes. You can add a serial port card and run a workalike called TDOS on it. Again lacks serial port out of the box.

I had an Epson QX-10 and I think it was the nicest in terms of form factor.
 
I've not used too many CP/M machines, but to my knowledge CP/M itself is mainly text-based. In other words anything that uses graphics has to have been custom-made for the machine.

I've only used the Tiki-100, a sort-of Z80 hybrid between a home-computer and a desktop. It's not really running official CP/M, but rather a clone equivalent to 56K CP/M version 2.2. It's more customizable than the official CP/M in terms of disk-formats and terminal emulation, but otherwise the software interfaces are just the same (letting most CP/M software run on the machine). What's great is that you could also get a x86 card for the machine, adding support for CP/M-86 "CMD" programs.

The CPU is a 4MHz with 1 waitstate on M1, and otherwise waitstates on video RAM access. There is 64K of RAM, up to 16K of ROM (bank-switched), 32K of video RAM (bank-switched as well), 3 graphics modes (256/512/1024 pixel x256 lines bitmap @ 4/2/1 bits per pixel respectively), 256-color palette selection, hardware vertical repositioning (can be used for scroll-effects), Analog out, digital out (limited palette), composite out and RF out. All 50Hz-PAL of course. AY-3-8912 Soundchip, Western Digital FD1797 Floppy controller, Parallel port with auxilliary cirquits for a casette connection (run by a Z80-PIO), dual serial-port (Z80-DART), a timer (Z80-CTC) and a keyboard with full n-rollover.

There was a few addons. As mentioned, a card with a 6MHz 8088 and up to 512K RAM was available and a HDD controller (WD1010-on-a-card) at least supporting half-height equivalents of the ST-412. I've only seen a single of these machine with HDD though, so that one is really hard to come by. Other additions were two different analog/digital I/O interfaces, a video-sync expansion, and a light-pen interface.

It's a very capable machine; sort-of like an Amstrad CPC 664 on crack. Only problem was that it really didn't catch on outside the educational sector due to inconvenient circumstances. The machine was designed from specifications set forth by the national educational departement, and they demanded CP/M compatibility. On release, it was clear that x86 and PC-compatibility was the future in business computing, and the Tiki-100 was simply to big and clunky to compete as a home computer. Needles to say, not much non-educational software was made, and only a fraction of that really took advantage of what the hardware could deliver.

But as a CP/M "text-only" machine it's very good. Using the different terminal-emulators and floppy-configurations gives it great compatibility, and the keyboard is rather comfortable as well. With the addition of the x86 card you can run CP/M and CP/M-86 programs seamlessly from the same command-line interpereter, and if you ever wanted to CP/M in 40x12 text using a font somewhat similar to Comic Sans, then I believe no other vintage machine gives you that option.

PS. The OS and its tools is in Norwegian.
 
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May seem boring but you could theoretically get an IBM 5150 or 5160 and run cpm-86. Then at least you have dos also and all the nice compatibility and cheapness of the x86 market.
 
Get a DEC Rainbow. Excellent build quality, super sharp smooth scrolling video (with color support), large capacity disk drives, and the best keyboard ever.

Rick
 
barythrin said:
May seem boring but you could theoretically get an IBM 5150 or 5160 and run cpm-86. Then at least you have dos also and all the nice compatibility and cheapness of the x86 market.
Click to expand...

Yup, you can run CP/M-86 with all of the graphic goodness of the PC interface (if desired), or Concurrent CP/M or MP/M-86 if you want to get fancy. If you've got a 5160, you can run CP/M-80 if you use a V20 CPU and the appropriate emulation package.

Or you can just run the whole shebang on whatever modern platform you have using virtualization software, like VirtualBox.

CP/M-80 suffers from the fragmentation of the 8-bit world, so you have some very basic command-line applications that will run on anything, and then the rest, which, if they aren't preconfigured for your particular hardware, will drive you nuts trying to get them to work.

There was a pretty good set of applications published for PC CP/M-86, including some applications that are also present in MS-DOS versions.
 
JonB said:
I seem to be getting very interested in CP/M and I'm wondering which is the best retro computer to run it on.

My parameters for "best" are performance, interfaces, hard drive availability, floppy size, keyboard quality, screen quality and graphical capability (not too important that one!)

I have a few already: TRS80 Model 4, amstrad 6128 and 8512, Tatung Einstein and Memotech MTX512. Of these, only the TRS 80 and the Memotech have hard drives (both implemented with modern flash memory).

None of them seem to fit the bill (although I do like the Model4).

What should I look out for, and why?
Click to expand...

Since all your machines use the Z80, I will assume you are interested in CP/M 80.
I think you already have one of the best machines, the pcw 8512, this machine was designed for "professional" users, there are a lot of them about, add-ons and CP/M software for it much easier to find than for older, more obscure systems.
I am not keen on the "rounded" look of the monitor and prefer the 9512 or pcw 10.

You may be able to find the 8Mhz accelerator that was developed for that range of systems, the HxC floppy emulator is almost as good as a hard drive, which of course were also available for the range, if you want larger floppy disks then you can fit 8" drives :) or 720/800k 3"/3.5" drives.
 
And high-resolution color graphics too, eh? :) Really, the OP didn't give us much to go on. What's the intended use? Some people play around with CP/M and get rather bored.
 
Workhorse CP/M:
Xerox 820s were good CP/M workhorses for me. Not fancy but solid.
I built systems around 3 motherboards from the Xerox factory surplus store.
I used them for:
. . . word processing,
. . . programming in Z80 assembly and BASIC,
. . . playing CP/M games,
. . . accessing BBSs over modem,
. . . running my BBS on one of them.
Floppy capacity was initially poor. I made a small PROM hack to take it from SSSD-40track to DSSD 80 track, quadrupling my floppy storage.
I wrote a BBS Diplomacy game (Avalon Hill) in Z80 assembly language and wrote a lot of cryptanalysis tools.

More Capable Workhorse CP/M:
The Ampro Little Board was a better system with more storage capacity on floppies. It ran CP/M 2.2 with ZCPR3; Ampro went a little crazy trying to make ZCPR3 menu applications. I just used these Ampros for writing and assembling firmware.

CP/M Disappointment:
I bought an SB-180 from Micromint in '86. It had CP/M 2.2 with ZCPR3... but I found it unremarkable and tedious. It only ran Non-Banked CP/M so the rest of the 256KB of memory just made a small RamDisk. I expected the SB-180 to be more useful, but I just ported my BBS to it.

My Best CP/M System:
My favorite CP/M system was the Japanese import, Mountainside Computers LTD, "Lat-1". It used CP/M Plus with ZCPR3 and EGA graphics... that was a very nice CP/M system. You could run Banked or Non-Banked versions; I used the rest of the 512KB DRam as a RamDisk. I used a Wyse 50 terminal as the console and had a Princeton color monitor hooked up for the EGA. I did a lot of astronomy programming for its graphics capability... took the Yale 9000 star chart database and condensed it to a useable form for displaying star maps.
 
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Ferguson BigBoard II
This is/was a versatile DIY board with lot of I/O capabilities (FDC, SASI, 2xserial, par in/out).
For upgrading it has an STD bus connector.
Best implementation is done with the VarBios from Twente Digital (Netherlands) and ZCPR 2.
Here is an picture of it.

Frank
 
Thanks for the replies so far!

The TRS80 M4 is a pretty good CP/M machine but I think it suffers due to the low quality keyboard. However, as you may know I also have a proper Wyse 120 terminal which is easy to configure as the console, and of course there is the "El Cheapo" IDE adapter as well as FreHD (which I haven't got round to trying yet). The M4 also has a good range of I/O ports.

I should have said that I want to stick to the Z80 based machines, and the most important things for me are the keyboard, screen and hard drive availability. Model 4 has easy HDD options but the screen & keyboard are not great. I want to use it for assembly programming and general tinkering, and I want it to be quick (relatively speaking). Emulation is out, because I want to use the real hardware.

For example: the Philips P2000C has a twin CPU design (one for applications & OS, the other to handle I/O like the Superbrain) and there is an optional board to support MS-DOS (there was one of these on eBay last week but I didn't bid enough). It's also got some graphics capabilities that you program via escape sequences (it seems to have an internal terminal board) as well as a built in SASI HDD interface with boot support baked into the ROM. It has a small green screen which looks very clear and a separate low profile keyboard (not sure how it feels). It's a luggable machine in the same form factor as a Kaypro.

I'm looking at a Kaypro 10 on eBay right now but I'm not sure the hard drive is working. And I have a Superbrain QD coming at some point which I committed to buy because I'd always wanted one. What do people think of these?

There are also the Amstrads, of which I have several, but they are poorly equipped for I/O, hard drives are rare and the screen & keyboard are poor. They also have those horrid 3" disks which make transferring data a total pain. I could fit 3/5" drives to one but I don't want to damage it.

Cheers

JonB
 
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Kaypros are solid CP/M systems, not super fast and not really expandable though. Big benefit is their rugged, industrial design -- plus, they fold up and can be stowed out of the way when you're done! Also common and cheap. I've only ever had/used Kaypro II systems, the biggest limitation there is floppy density.

The SuperBrain is supposed to be a decent machine -- I've wanted one for a while, but never have spare cash when they show up. Kermit was written on the SuperBrain.

With a bunch of S100 hardware around, my "best" CP/M system is of course a stack of S100 boards. Mostly I like playing around with S100 hardware, plus you get to use whatever terminal you like with it, including a PC running terminal emulator software. It's probably the most flexible option, but also the least likely to "just work," unless you find a turnkey system like the CompuPro 8/16.
 
JonB said:
There are also the Amstrads, of which I have several, but they are poorly equipped for I/O, hard drives are rare and the screen & keyboard are poor. They also have those horrid 3" disks which make transferring data a total pain. I could fit 3/5" drives to one but I don't want to damage it.
Click to expand...

The Amstrad Z80 systems are an interesting bunch! They can have a standard 720K floppy added in addition to the Amdek drive. That big 50-pin Centronics connector on the back has pretty much the entire Z80 pinout, plus some extra Amstrad specific lines. One of my "maybe eventually" projects is to build a S100 card cage to go with the Amstrad. That would make it a really awesome little CP/M box!
 
glitch said:
Kaypros are solid CP/M systems, not super fast and not really expandable though. Big benefit is their rugged, industrial design -- plus, they fold up and can be stowed out of the way when you're done! Also common and cheap. I've only ever had/used Kaypro II systems, the biggest limitation there is floppy density...
Click to expand...

Kaypros are solid CP/M systems
Agreed. Nice reliable system in its day. We had about 4 in the lab at ECA back in the mid 80s hooked up to a receiver to monitor our local clients' radio packet communications. If they had a problem we could access it from the lab immediately.

Kaypro IIs were also tough. I had ECA send me one when I was assigned to Phoenix for a few months. It survived the air freight on its own. It was a very capable system and it allowed me to work on my other project during the slow periods at that site.
 
There were a few fairly spectacular CP/M Z80 boxes from Japanese sellers such as Fujitsu and NEC. Multi-CPU, lots of memory, etc.

I started losing track when the "super" Z80 CPUs, such as the 64180 came out, but I wouldn't be surprised if there wasn't some choice hardware using those.

But you still haven't said what you'd like to do--and that complicates matters. For example, I have an Amstrad "Joyce" word processor, but it has 512K of RAM and high-resolution graphics. Swap the awful 3.0" CF2 floppies for 3.5: 720K ones (you could probably even use 1.44M floppies with a bit of patching) and you really have a nice floppy-based system that runs CP/M plus. Yet, it wasn't that long ago, that you could have one of these for the asking--I think that they're still considered as landfill.

There were lots of Z80-based CP/M computers--many of which you've never heard of.
 
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