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Comment by zh3 | Hacker News Reader

800MIPS? Not off an 11/70, for sure - much, much slower than that. 11/23's were as fast (or faster, depending on options and application) and they were maybe a single MIP or so (still got a couple of PDP11's kicking about, every so often I fire them up just to check my hearing).

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From memory.

(The original) VAX 11/780 was a 1 MIPS machine. 32 Bit.

pdp 11 was a slower machine. plus it was 16 bit. slow clock, a relatively cheap o'scope could be used to snoop the buses.

The original PDP-11/70 was 0.7 vax mips. So it was 70% as fast as a Vax 11/780. I believe (from memory) the Vax 11/780 could do ~1757 dhrystone 2.1 mips so a PDP-11/70 would be about 1230 dhrystone mips. https://wiki.cdot.senecacollege.ca/wiki/Dhrystone_howto

Indeed, back in the day we bolted QBus backplanes to the side of DIN41612 backplanes and wire-wrapped across to a bunch of boards each with 100+ TTL chips on them (the 5V PSUs were something like 120A). The bus clocked at around a MHz, hence loosely the instruction rate (and back then, the addressed memory or peripheral needed to ack the bus cycle or there'd be a bus fault).

50 cent ESP-8266 would make excellent PDP-11. Except much too much memory. And 20 times too fast.

https://www.espressif.com/en/news/news/ESP32-Powered_PDP-11

..."just to check my hearing"

I got a good laugh out of that....

Yes. Looks like I slipped a few decimal points.

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