>>>
So, has anyone come across a good
online resource which compares vintage CPU
instruction sets? It'd be useful to see what 'core' instructions* were most
common back in the day and use that as a basis for my own homebrew
effort;...
* My hands-on knowledge is pretty much limited to Z80, 6502, 68000 and x86,
and it'd be nice to go a little further back in time - but hopefully without
having to download and digest many different databooks!
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It sounds like what you really require is information on vintage computer
_architectures_ (probably from the programmers view).
The classic text on the subject is, luckily, available online from a rather
unexpected address:
http://research.microsoft.com/en-us/um/people/gbell/Computer_Structures__Rea
dings_and_Examples/contents.html
[Computer Structures: Readings & Examples, by Gordon Bell]
As personal thoughts on the subject and going backwards in time I'd think of
looking-at and comparing the following.
The two pre-micro classics, nay extremes, of CISC:
*IBM system 360/370/... [Multi-GP-register - store organisation with a
sprinkling of store-store operarions]
*DEC VAX (and its simpler predecessor, the PDP-11) [address-modes-R-us]
The RISC before there ws RISC:
*CDC6600
The classic 36-bit architectures
*IBM709/7090/7094 [single accumulator/few index registers]
*GE6xx/Multics/Honeywell L66 [similar architecture, taken to its limits, and
(in later models) even more address modes than a VAX]
Traditional mini-computer
*PDP-8
*PDP-11
any of hundreds of 16 or 18 bit accumulator-store designs ... they tend to
be very similar - like PDP9 or CDC1700 or EAL640 or ...
"Weirdos"
*Burroughs B5500 [stack structured]
*IBM 1620 [pure store-store organisation]
*IBM 650 [and the effect of having program memory on a drum]
Other cases of interest
*Ferranti Atlas [virtual memory before IBM invented tomorrow]
*FP6000 became ICT1900 [multi-register - store but simpler and less general
than the '360 ... and 24 bits]
*MU5/ICL2900 [designed for block-structured high-level-languagues - pity
ICL's main market was
for people who used COBOL]
Andy