bit slice chips (was Re: Harris H800 Computer)

I built a 32-bit micro-engine for a project that was eventually going to be an IBM 360-line CPU. I pieced the 360, not because it was the greatest design, but it was VERY well laid-out and would be easy to write efficient microcode for. I used the 2903 with 2910 controller. I was able to get it to run at 8 MHz, with 3-address operations running at 6 MHz. But, the project got bogged down, as at a certain point, I realized HOW MUCH more work lay ahead of me to get a working system. I had to add 2 more features to the micro-engine - a 256-way branch from the op-code, and some OR gates to OR in the register address fields. Then, I had to build a system bus and memory interface. (I was going to make the I/O architecture much more like a PDP-11 than the 360 channel architecture.) Then, I had to design a general-purpose peripheral controller. I had a VERY rough sketch for about a 20-chip micro-machine using (probably) 3 byte-wide EPROMS for instructions) that would hopefully run at 4 MHz. Then, I had to build a SCSI controller (I already had a SASI disk on my S-100 system), a serial mux and a tape controller. Finally, I had to write at least a primitive OS and figure out how to come up with compilers for it. Had I known that UNIX-360 existed, I might have tried to make some kind of port of that. But, obviously, YEARS of work would have been needed to make it usable. See http://pico-systems.com/stories/1982.html for some pics and description of it. Jon