Collectables? - test-drb@ccmp.vtda.org

13 Nov 2005

...

Subject: Re: Collectables?
   From: "Chuck Guzis" <cclist at sydex.com>
   Date: Sat, 12 Nov 2005 19:40:32 -0800
     To: cctalk at classiccmp.org

On 11/12/2005 at 10:10 PM Allison wrote:

 Original topic: I'd like to get that
Polymorphic to build a small system.

I'm thinking Cpro CPUZ, Cpro Disk1A, Interfacer-II and Ram22. That will
build a z80, floppy interfaced, 256k with enough parallel IO to do an 
IDE.  
It's yours as a bare board for USD $10 and with 6 nice new gold-plated
connectors $20.  Shipping extra.  I seem to recall that Polymophic tied the
data in and data out together on their boards, but the MB doesn't show
that. 
6??? I thought it was four slots.  It's a deal, I'll get you you off line.

...
 I used to have the IMSAI floppy disk system too, but
that wasn't engineered
nearly as well as the CPU box.  One small power supply for each Calcomp
floppy with some blinkin LED's on a small front panel.  I retired the IMSAI
FDC and Calcomps (the stepper motors eventually both shorted out).
Replaced the drives with Siemens double-sided units and used Don Tarbell's
FDC.  Much improvement.  I used that setup until I retired the system.  The
MITS 4K DRAM boards got replaced with some SSM SRAM (lots of 2102's)
boards.  The CPU was a Z80 board of uncertain vintage.

I suppose the whole mess could be replaced with a Rabbit CPU and a one-chip
FDC. 
Yep but not near as fun or noisy.

...
  On a related
note I've been doing some 1802 coding and that 1977 NS*
box is still running Avocets 1802 assembler under cp/m.  Still kicking
after 27+ years. 
The 1802 was barely capable as a CPU.  The only redeeming thing was that it
was static CMOS and could be run down to a DC clock rate.  But that was
true of the IM6100, too, wasn't it? 
Yes the CMOS 6100 and 6120 wer static.  The 1802 still has a following.
It's a bizzare part, dumber than an 8048, almost one step down from
a PDP8 but none the less useful and people are still using it!  Its 
attractive feature was romless with simple front pannel could be 
built until I did it with and 8035 and fewer parts. The DMA was nice
but hard to use and killed CPU bandwidth.  Yet I have three working
flavors of it and the first was an ELF built off the PE article when 
it appeared.

Come to think of it in the homebrew computer hobby the Z80, 6502, 1802,
and maybe the 6809 are the top players to this day.

...
 Were there any hobbyist systems built around the
Fairchild 9440 almost-Nova
chip? 
Oh, the microFlame.  Never saw a hobbiest system of one.  I think the only 
customers that ever saw one were military contractors. Tried to buy one 
and got blown of by the fairchild rep.  I do have a die in lucite 
paperweight for that effort from one of their promotions.

Allison