From: Warren Toomey <wkt@cs.adfa.edu.au>
Message-Id: <200005100150.LAA90764@henry.cs.adfa.edu.au>
Subject: Re: Help: PDP-11 instruction classification
In-Reply-To: <85og6g18xo.fsf@junk.nocrew.org> from lars brinkhoff at "May 9, 2000  9:25:55 am"
To: lars@nocrew.org (lars brinkhoff)
Date: Wed, 10 May 2000 11:50:31 +1000 (EST)
Cc: pups@minnie.cs.adfa.edu.au (Unix Heritage Society)
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In article by lars brinkhoff:
> So far, this is the classification I've come up with:
> 
>   BASIC: the basic instruction set.
>   CIS: commercial instruction set (opcodes 0x7d00..0x7eff).
>   EIS45: 11/45 extended instruction set: MUL, DIV, ASH, ASHC, SPL.
>   EIS40: 11/40 extended instruction set: EIS45 + SOB, XOR, MARK, SXT, RTT.
>   FIS: FADD, FSUB, FMUL, and FDIV (opcodes 0x7a00..0x7bff).
>   FPU: LDF, STF, LDCFF', STCFF', CMPF, LDEXP, STEXP, LDCIF, STCFI, MULF,
>        MODF, ADDF, SUBF, and DIVF (opcodes 0xf000..0xffff).
> 
> Would this be correct?
> 
> FIS and CIS isn't imlemented in Supnik's simulator, and I haven't
> found any documentation.  Does anyone know more about those?  Why
> is there both an FADD and an ADDF instruction?

I've got some details on FADD, FSUB, FMUL, and FDIV. I could fax you the
relevant details from the processor handbook, and/or give you source code
from my Apout simulator.

FADD is instruction 07500x, ADDF is 1720xx. They are different.

I don't know enough about the CIS extensions. Can you name some of the
opcode names, so that I can look in the handbooks I have here: 04, 05, 10, 15,
20, 34, 35, 40, 45, 55, 60, 70.

	Warren