Speaking of multiple processors...

[Allison]

>
>Subject: Re: Speaking of multiple processors...
>   From: M H Stein <dm561 at torfree.net>
>   Date: Fri, 16 Nov 2007 14:30:25 -0500
>     To: "'cctalk at classiccmp.org'" <cctalk at classiccmp.org>
>
>---------Original Messages:
>Date: Fri, 16 Nov 2007 08:57:12 -0500
>From: Allison <ajp166 at bellatlantic.net>
>Subject: Re: Speaking of multiple processors...
>
>>   From: M H Stein <dm561 at torfree.net>
>>   Date: Thu, 15 Nov 2007 11:29:05 -0500
>
>>Cromemco also had Z80s on their I/O processor boards, and when the later 680x0
>>CPU boards dropped the Z80 you could still run your Z80 programs on the I/O card.
>>
>>mike
>
>This is not uncommon.
>
>H89 had two, one for the terminal and the other was the processor for
>the computer.
>
>My NS*Horizon had two when I added the Teletek HDC(hard disk) as that 
>has a local z80.  When I added a smart FDC of my own design and later
>smart printer spooler and other IO with local cpu the nuber fo cpus grew.
>
>The Compupro system can easily have three, ZPB, Their mux board and 
>any of the hard disk controllers.  I have one that has 68000, 8085 and
>Z80 (maincpu, mux and Disk3).
>
>It's something that isn't unusual as it would seem.
>
>Allison
>
>----------Reply:
>Well, I didn't say or imply that dual-CPUs like Cromemco's DPU and XPU or 
>intelligent I/O co-processors like their IOP and Octart were uncommon; in 
>fact I was just adding Cromemco to the list under discussion which ranged 
>from CDC big iron down to C-64s, and both C-64s and Cromemcos could
>easily have 4 or 5 CPUs talking to each other one way or another.

They were not alone doing that.


>But now that you mention it, I did think what Cromemco did when their XXU 
>68010/20 CPU board finally dropped the Z80 _was_ a little unusual; although
>the Z80 was gone from the processor board, your Z-80 CDOS or CP/M 
>application could still use the Z80 on the existing I/O board when it wasn't
>handling I/O traffic. Did anyone else run *application* programs like a word
>processor or spreadsheet (as opposed to applications like the C-64's disk
>utilities) on an I/O co-processor board?

I guess it could.  Never messed with Cromemco but they had nice hardware.


>And that's not quite the same either as e.g. an Apple or the SuperPet, which 
>effectively just used the main system as console and memory for an *added* 
>co-processor.
>
>Admittedly, at some point the distinctions do get a little blurred.

Way fuzzy. 

Allison

>m