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... 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.

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?

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.

m