Re: Past Blast - "Wonder Woman 1984" - Corp Guy Using PET

On 4/3/25 2:42 PM, rbowman wrote:

On Thu, 3 Apr 2025 06:26:16 -0400, c186282 wrote:
 

    Also always wanted a good S-100 system ... but could not afford one
    way back then. THINK they hung on all the way to the 68k chips, but
    after that the bus was too slow. NOW I can't afford a working re-sell

 The rumor back then was the S-100 bus came from someone finding a great
deal on milsurp edge connectors. There were a number of alternatives.
 https://en.wikipedia.org/wiki/STD_Bus

   I can believe it ... hey, why use EXPENSIVE custom
   edge connectors ?  :-)

Despite the name, the STD bus wasn't a standard. Sprague Electric had a
severe case of NIH so I designed a bus for them that used a Z80 processor,
memory cards, and I/O cards. You could get away with a lot with 3.57 MHz.
It was fun and they were willing to pay for the project but a COTS
solution would have made more sense.

   Sounds like you went further into custom electronics
   than I ever did. However, back in the day, DIY was
   much more common and NEEDED.
   I'll have to check ... I think S-100 was solid up to
   four or five MHz. The Z80s were the most common CPU
   but I'd seen them with lots of others. The main reason
   to stick with S-100 was all the ready-made periph cards
   back in the days when the CPU board did NOT have built-
   in everything. Had to have a sep serial board, sep
   printer card(s), sep drive interface card(s) .....
   indeed I think on some even the CPU was not all on
   one board.
   According to one source, Cromeco sold a 16.7 MHz 68020
   board for S-100 ... but that'd be pushing things.
   Alas the biggest problem was that the use of those
   100 lines tended to 'evolve' over time, which could
   increase incompatibility issues.
   Anyway, I'd be happy with a Cromeco Z80 with a floppy
   and serial board and maybe 128kb. Good solid CP/M
   system blast from the past. Yes, you can buy TINY
   Z80 SBCs now, even seen kits ... but that's not as
   fun or impressive  :-)
   Hey, the earlier versions of Turbo Pascal came
   with a CP/M variant ... don't remember if that
   was just CP/M-86 or actually for Z80s.