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The specific variant that it was compatible with was still relevant, sold and manufactured design at the time of the introduction (ca. 1985? maybe a bit earlier
by p_l 5y ago
The specific variant that it was compatible with was still relevant, sold and manufactured design at the time of the introduction (ca. 1985? maybe a bit earlier). It was a very capable CPU for its weight class, and actually more packed than Digital's offering at the time - most LSI-11 at the time required two separate chips minimum, and didn't have 1801VM3's later "MCU" variants.
The reason for it was that it wasn't designed as PDP-11 clone - it was own design, which at the last moment got modified to run LSI-11 instruction set and support QBus, due to orders from on-high to standardize on PDP-11 compatibles in the segment it was made for.
- guenthert 5y agoWasn't it originally meant to be used my the armed forces? I think the '85 introduction to the general market was only after the original users considered it not competitive anymore.
- p_l 5y agoNope. It was originally meant to power industrial machinery, and in fact some very early chips that used the in-house instruction set were made and ended up AFAIK in some fabrication machines (lathes, mills, etc). Afterwards it was a welcome upgrade for PDP-11 based lines, including military spec models, where reliability was more important than pure speed.