On 4/10/24 10:20, Jon Elson via cctalk wrote: > OK, never worked on one, I did actually see one in a tour once. So, > there's a lot I don't know about the /20. Thanks for the correction.
In point of fact, given the constraints posed by the small register file and lack of instructions, the primary way to do math on the 2020 was the SS decimal instructions. At least there you had multiply and divide instructions. That sort of figures, given that the object of the 2020 was to replace a lot of the 1401 gear. That's one of the reasons that many don't consider it to be proper member of S/360. In the 1970s, I recall that the USAF Logistics Command was running their old 7080 COBOL-with-Autocoder patches on S/370 gear. When visiting AFLC at Wright-Paterson then, I do recall seeing at least 2 7080s still functioning. It was explained to me that very few of those GSA programmers knew how much of the old system really functioned, so emulation was a logical step. Wasn't the California DMV in a similar situation for years? --Chuck
