Intercept Jr. Schematics - test-drb@ccmp.vtda.org

17 Apr 2009

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Subject: Re: Intercept Jr. Schematics
   From: "bfranchuk at jetnet.ab.ca" <bfranchuk at jetnet.ab.ca>
   Date: Thu, 16 Apr 2009 17:56:37 -0600
     To: General Discussion: On-Topic and Off-Topic Posts <cctalk at
classiccmp.org>

Vincent Slyngstad wrote:
  From: Ethan Dicks:
 Sent: Thursday, April 16, 2009 3:20 PM

 On Thu, Apr 16, 2009 at 6:01 PM, bfranchuk wrote:
  PS Did some other early computer have the
ability
 to run the 6100 cpu as well as 8 bit cpu's? 
 Are you thinking of the CP/M board in a DECmate II?  
 It might be what be what Ben was thinking of, but the DMII is actually 
 based on the 6120 CPU, not the 6100. 
No.  I think I read about it in kilabuad, rather than a early BYTE.
I think they supported a 8080, 6502 and 6100 as add on cards.
Remember this was the time hardware tended to vanish overnight
as well as your $$$. 
The DECmateII was 6120 cpu (PDP-8A similar) and there was an Z80 based APU
that ran CP/M and there was also for the DMIII both Z80 APU and also 
an 8088 based APU that ran CP/M-86 and DOS.

Since I have a few DMIIIs I know for sure about the Z80 APU and I've used the 
DMII Z80 APU to run CP/M.

General the DMIII is a smaller form factor DMII with a few minor adds
and tweeks.

The 6120 is a 6100 with Integrated 6102 MEDIC (timer, DMA, EMA) and 
some minor micro cycle tweaks and process improvements to make it a 
bit faster.  If you have a 6100 and 6102 it's 99.4% the same as 6120.
I have systems based on both. Generally wahn I want to play on raw iron
the PDP-8 (or 61xx) archecture satisfies me for shear simplicity.

The Digital Group system could have a 8080, Z80, 6502 and 6800 CPU but
didn't do the 12bit 6120.  The 12bit width of 6100/6120 was odd to many 
systems.

Allison