Talk:SDS Sigma series
|WikiProject Computing / Hardware||(Rated C-class)|
I suspect the instruction format was the same for all 32-bit Sigmas, but hesitated to say so without checking the manuals. — Preceding unsigned comment added by Peter Flass (talk • contribs) 06:46, 22 January 2012 (UTC)
- OK, I checked the Sigma 5/6/7/8/9 manuals at bitsavers.org. The general format just has a 17-bit address field; the different interpretation depending on the high-order bit of that field is specific to the Sigma 9 in if "real extended addressing", which is a mode that allows non-virtual access to more than 128K words of physical memory, is in effect.
- The manuals also describe a different format for immediate instructions, so I left this as just describing memory-reference instructions. Guy Harris (talk) 02:24, 23 January 2012 (UTC)
"At the time the only competition for the Sigma 7 was the IBM 360."