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Sure, but if memory serves me correctly, many early workstations used a microprocessor with an external MMU. It is misleading in the sense that it is not part o
by II2II 4y ago
Sure, but if memory serves me correctly, many early workstations used a microprocessor with an external MMU. It is misleading in the sense that it is not part of the Z80, but it is in the character of the times. (And MMUs are not the only CPU feature that was originally external. The FPU is an example that more people will be familiar with since it was an upgrade path available on many personal computers.)
- jandrese 4y agoI don't think MMUs were common on machines that ran on a Z80 however.
- NegativeLatency 4y agoFor example a Programmable MMU was an optional add on for the Macintosh II (which wasn’t a z80 but serves to illustrate the time when they began to become available to home computers)
- DonHopkins 4y agoThe home-brew pager (MMU) of the MIT-MC PDP-10 KL10 was appropriately called "KL-UDGE". (KL was the prefix of the PDP-10 model). https://en.wikipedia.org/wiki/Kludge https://en.wikipedia.org/wiki/Kludge It's on display at the Paul G. Allen Living Computer Museum. https://sites.google.com/site/mthompsonorg/Home/pdp-10/pdp-10-serial-numbers https://sites.google.com/site/mthompsonorg/Home/pdp-10/pdp-1... https://donhopkins.com/home/catalog/images/mc-console.jpg https://donhopkins.com/home/catalog/images/mc-console.jpg Lars Brinkhoff has taken photos of the KL-UDGE blinken lights panel and naked wire wrap boards: https://twitter.com/larsbrinkhoff/status/1128601896619524097 https://twitter.com/larsbrinkhoff/status/1128601896619524097 >Photo 6/7: KL-UDGE lights panel >Photo 7/7: KL-UDGE boards. Real-time time of day clock?
- wk_end 4y agoWas on display. The LCM closed due to COVID and there's no indication that it's coming back, sadly.
- 300bps 4y agoThe Commodore 128 had an 8502 CPU, a Z-80 CPU and an 8722 MMU. Was a pretty popular machine - sold 5.7 units worldwide. But probably only a tiny fraction actually used the CP/M mode that used the Z80.
- jandrese 4y agoWow, I had no idea there was basically a second computer hiding inside of the C128. No wonder it cost so much.
- anticensor 4y agoDid you mean 5.7M?
- philistine 4y agoI don't know what's more concerning. The fact they only sold 5.7 units, or the fact someone managed to only buy .7 of a Commodore 128.
- otto2 4y agoThe sixth unit had CP/M disabled, so accountants wrote it down as 0.7 units.