The List!

From: Susan M Johnson <sjohnson_at_GAS.UUG.Arizona.EDU>
Date: Fri May 2 18:36:03 1997

On Thu, 1 May 1997, Bill Whitson wrote:

> Hi all.
>
> After getting your numerous recommendations on the last
> version ;) I updated the List of Classic Computers. It
> now includes 83 more machines and notes as to CPU, base
> RAM, Primary OS,
>
>
> ==================================================================
> MANUFACTURER
> MODEL CPU RAM OS TYPE YR
> ==================================================================
> Zenith Data Systems-----------------------------------------------
> Z-89 Z80 48K ?? MICRO 79
> Z-90 Z80 64K ?? MICRO 81
> Z-100 8088 w/8085 192K ?? MICRO 82

To add to his list, fill in blanks:
                        
   Z-89 CP/M
   Z-90 CP/M
   Z-100 192K/768K CP/M & Z-DOS

  Heath Corporation-------------------------------------------------
   H-89 Z80 48K CP/M Micro 79
   H-90 (?)
   H-100 8088 w/8085 192K/ CP/M & Z-DOS Micro 81
                                        768K

  The Heath Corp. computers (Heathkit) actually preceded the Zenith
computers, although they are basically the same computer: the Heath
version is the kit form, and the Zenith version is the factory assembled
form. Heath originally designed them, then Zenith acquired Heath. I
think the H/Z-100 was the first they worked together on.

  The Heath/Zenith H/Z-100 is a dual-operating system computer, running
both CP/M and Z-DOS (Zenith DOS), then later Zenith-modified MS-DOS. The
CP/M runs on the 8085, and the MS-DOS/Z-DOS boots up on the 8085, then
switches to running on the 8088. Other OS available were CCP/M, CP/M-86,
MMP/M (very brief), and I think that there was also a version of Xenix
available, although I'm not positive about that. Seems to me it was also
possible to get the Pick OS, but again, my memory is hazy as to that. At
any rate, neither was the main OS if they were available.

  Once the 41256 RAM chip became available, the H/Z-100 had a maximum of
motherboard RAM of 768K (became available from Heath/Zenith in 1985, I
think). It's capable of addressing 16 Meg if someone wanted to put it in,
although they would have to write their own software to manage it.
 
  Currently, the H/Z-100 can run 8", 5 1/4" (40 & 96 tpi), and 3 1/2" (96
& 135 tpi) floppy disk drives; MFM hard drives (also RLL, although not
common), tape drives, and SCSI drives. CD-ROM drives are also possible.

  It was designed to run both 8- and 16-bit software, so people who had a
big investment in 8-bit software running under CP/M would be more willing
to buy a new computer. That dual OS design sold the military on the
computer, and Zenith made a bundle on military contracts for it.
  
  Original operating speed was 5 Mhz; Heath/Zenith later upped that to 8
MHz. A common modification allows it to run at either 8 or 10 MHz.
Someone has also managed to get it running at 33 MHz.

  However, it is not PC-compatible due to the S-100 buss design and the
video. You can run a great deal of PC software on it, although
the code may need patching in order to do so.

  Hope this adds to your computer list & provides interesting information.

                                Susan
Received on Fri May 02 1997 - 18:36:03 BST