CP/M and MS DOS on A8

[high voltage]

Anyone ever used that ATR 8000 from SWP? Did it work properly? Could you really run CP/M software successfully? I only ever managed CP/M on my C-128, just about bearable.

And MS DOS? Wow, a PC for $500? I would have bought that straight away.

 

[erazmus]

The ATR-8000 successfully runs CP/M on any A8. You will need a 360k 5.25" floppy drive to plug in to the ATR-8000 in order to do this. The A8 drives aren't visible to CP/M, but the ATR-8000 drives are visible to the A8.

 

As for MS DOS compatibility, I think this was provided by a plug-in board for the ATR-8000. I'e only ever heard mention of it, but never seen one in real life.

[ricortes]

I'll apologize up front. Usually my memory is pretty good but things that strike me as not important enough to warrant dedicating brain cells to go into volatile.

 

As erazmus says, you needed the ATR-8000<$600> plus the co-power 88 board for another $400. You were looking at $1000 w/o monitor or keyboard<more later> for a floppy based MS DOS and CP/M system. To do anything resembling a power user, you also needed a hard drive. IIRC: Hard drive interface was something like 8500 or ATR8500 but I could be thinking of a later generation ATR. I think Ben Phoeland<spelling?> owned one of the HD interfaces but dropped out of the Atari scene decades ago.

 

I'm thinking back to some of the junk I owned back then and the ATR just wasn't competitive. I owned a Sanyo MBC 550 that I picked up with a software bundle for ~$225. They were a byproduct of the Heathkit type kits that came with a 'teach yourself computers' course. Another one I had was an Epson I bought new for $599 that came sans monitor but with a CGA built in. I guess what I am trying to say is I am taking your comment as a bit of intentional on your part, humor. The ATR8000 doesn't even include a floppy drive, cables, or drive enclosure! You would be lucky to get away with a $2000 investment to make a workable MS DOS system. Software bundle that came with my Sanyo was Wordstar, Calcstar, and I think a database program.

 

Everything CP/M expects an 80 column screen. The work around everyone Atari took was using a graphics 8 screen with 3 bit wide FONT. This was workable when the world was a slower 300 BAUD but took a severe head blow when things sped up. This made Atari<=>CP/M a terrible match or at least obsolete right out of the gate. I am one of the believers who say the original MS DOS was just a copy of CP/M for the 8080 that was just disassembled and rewritten for the 8088, so naturally the same hold true.

 

There are a few ATR's floating around. I have one and a few other long time Atari users have them too. I probably have this wrong but I think a lot of the CP/M disks floating around have a disk format translation error. The ATR has no trouble understanding single and double density Atari disks but on a double density Atari disk, the first 3 sectors are only 128 bytes in length. I believe the copies in circulation were made by copying CP/M disks to an Atari disk drive which truncated the first 3 sectors. Steve Sheppard supplied me with copies of CP/M disks years ago but it was right at the start of another one of my relationships with a computer hating girlfriend! She actually smashed two chairs I was sitting on while using my computer! Took me a while to win her over but now she spends as much time as me on computers so I am just starting to get my head out of the sand.

 

The good: Early versions of Sparta DOS came with a program to turn on an ATR8000 in CP/M mode. There was also OMNIVIEW which three claims to fame were built in 80 column, 800 OS B compatibility, and built in ATR8000 terminal mode. I vaguely recall there was some odd sequence to get everything up on OMNIVIEW, something like multiple resets with holding down various keys and eventually you would get something like "BOOT?" prompt on your Atari screen. I think allowable responses were something like A or B for the CP/M drive nomenclature. Anyway, you don't have to find the $30 AUTOTERM program in the ad above to get to that stage.

 

On using an ATR8000 as an Atari disk drive, mostly positive with some serious nags. On my system I have an old SCSI drive enclosure with 4 drives. Mine are a 3.5" 720kb, two 5.25" 360kb, and a 5.25" quad density drive switchable between 360kb and 720kb. Just over two megs of floppy which IMHO is still a pretty decent system for just about anything you would want to do. I've heard there are even options for running 5.25" 1.2 meg floppies to simulate 8" 1.1 meg floppies but I never investigated it. I've used my ATR8000 with both the printer and RS232 interface w/o problems. Given a choice between buy an ATR8000 or an Atari 850 interface, you would IMO be better off with a naked ATR8000.

 

The nags: System was really set up by SWP to use MyDOS and 8" drives. 8" drives were weird beasts! They got their disk rotation speed from a ~synchronous AC motor and belt drive that ran continuously. This meant they needed a head load solenoid to lift the r/w head off the drive whenever it wasn't doing any actual reading or writing. To speed up Sparta DOS the delay for head load timing was dropped from some versions. SDX will work with an ATR8000 but every time you access the disk drive you get moans and groans as it times out. This put me between a rock and a hard place since I loved both my SDX and my quad density drive in my ATR8000. My quad density 5.25" drives still used the head load solenoid just like the old 8" drives! The serial I/O in an ATR is bit banged! NO UART! Everyone loves the high speed I/O of drives like USDoubler or Happy. Once you go high speed, it is hard to go back. It would take a major rewrite of the ATR8000 BIOS or some major hacking to install a UART to get the speed beyond its current 19,200 BAUD.

 

I've softened a bit on my CP/M position. Technically I have three systems if you include the ATR8000 w/o working CP/M disks and a H89 that was wired as a terminal but still has the CP/M motherboard in it but no CP/M disks. If you wanted to learn Pascal, Z80/8080 ML programming, or just take a trip down memory lane on real hardware vs. emulation, CP/M has a lot of tools you could use. It will be a tortuous path but I will make an effort to get an old MS DOS system set up so I can do some sector editing and refresh my DEBUG sector editing skills.

[erazmus]

Excellent write-up ricortes. Another solution for A8 CP/M is running it on an Indus GT drive with a memory expansion. I have the drive, but no expansion card, so I've never tried it. Here's a page with disk images and schematics for a memory card

 

http://trub.atari8.info/index.php?ref=cpm_en

[+Stephen]

I run CP/M on my system with the Indus GT drive. I have a few dozen disk images, it's cool to read some source code with comments from 1978.

[erazmus]

Stephen - Best. Avatar. Ever.

[ACML]

I ran CP/M through my 800 via a 64K ATR8000 back in the mid 80's. I used the Omniview 80 OS to view text on an NTSC monitor. I actually used it quite a bit in college. I used Wordstar and EnerGraphics to complete my senior wind tunnel project. Couldn't see the graphs until they were printed to my Mannesmann Tally dot matrix printer. It was a text only thing. I occasionally think about acquiring another ATR8000, but quickly come to my senses. If I really want to relive CP/M, I'll use an emulator. It is very hard to find an ATR8000 that are known to work. Any purchase on Ebay is a leap of faith that this 30+ year old computer still works. I owed two in the 80's and the build quality was not exceptional. Atariwriter and Syncalc made the argument for CP/M pretty weak. The 8-bit Atari now had better apps than CP/M. Gary Kildall (creator of CP/M) was a pioneer for sure, right up there with Wozniak and Ed Roberts and Gates. MSDOS and Apple DOS have their roots in CP/M. IBM could have easily chosen CP/M as the standard. Glad I was exposed to it, but have no really reason to revisit that path. Enjoy!

Edited August 12, 2013 by ACML

[Caterpiggle]

Hello erazmus,

 

I do have ATR8000 machine and I have not been using it yet. I will let you know when I might set-up in 1 day. Will give try if it is works ? I do have Co-power 88 sticker outside ATR8000. I do have Indus GT drive but no expansion. So will it work on my ATR800 for reading any MS-DOS format 360 K ?

[+Stephen]

Stephen - Best. Avatar. Ever.

Thanks - it displays beautifully on my 130XE. I used Rasta Convertor to create it - check that thread if you want the XEX.

[+wood_jl]

ricortes and ACML:

 

You both told me everything I ever wanted to know, in a couple of posts. BRAVO!!!!!

[Subby]

I had my ATR-8000 on display at VCFSE, mostly just to show an Atari 800 "running" CP/M.

To do anything other than show off you need an 80 column card. On my composite Amdek monitor you could almost read the software driven 80 columns. Almost.

One of these days I do want to get it's 8" drive repaired.

[+Stephen]

Here's a video of CP/M running WordStar via my Indus GT.

http://www.youtube.com/watch?v=Z21kW0uQOyE

[Subby]

Oh, I like that Stephen. How is it doing 80 columns? (sorry, I have no sound ATM so if you explained it I couldn't hear it)

[Caterpiggle]

Hello Stephen,

 

Please read above with my username there. I do have my own Indus GT drive but no expansion card installed. So how it will work on my ATR8000 with Co-Power 88 ? Please explain to me about my Indus GT available with card installed ?

[+Stephen]

Oh, I like that Stephen. How is it doing 80 columns? (sorry, I have no sound ATM so if you explained it I couldn't hear it)

The term program which communicates with the drive, uses a software 80 column driver. SDX can do this in software as well, or even better, in hardware if you have a VBXE.