Date: Sat, 20 Feb 1999 12:54:34 +0300
From: "Stas Pereverzev" 
To: MISC
Subject: Re: nFORTH v2.3
Content-Type: text/plain;
	charset="koi8-r"
Content-Transfer-Encoding: 7bit

>Comments, folks?


You need only five instructions, not 16. They are:

ALU:
1. nand
2. shr

RAM:
3. store ( addr n -- )
4. lit   ( -- n )

CONTROL:
5. ncret  \ JUMP to addr in N, if carry flag isn't set in T,
          \ also drop both T and N


Also, if PC is memory variable (or can be addressed as memory variable)
we can awoid "ncret" instruction:
In that case we sholud use NCSTORE instead STORE:
ncstore (addr n flag -- )

ncstore (addr n 0 ) - same as store,
ncstore (PC n -1 )  - same as ncret

We need only 2 bits per instruction in that case.

That all folks ;-)

Stas.