On Tue, 18 Mar 2014 11:00:14 -0500, Paul Gilmartin wrote: >On Tue, 18 Mar 2014 09:56:17 -0500, Tom Marchant wrote: > >>... The s/360 >>model 67 supported 32-bit addressing, while s/370 was limited to 24-bit >>addressing >>until XA in 1982 or 1983 began to support 31-bit addressing, not 32-bit like >>the >>model 67. >> >How did the 67 deal with legacy code's use of the sign bit to terminate >parameter lists? Did it also have a 31-bit mode? But I suppose most >such code was written for 24-bit addressing.
Legacy code would have been code written to run under OS/360 or DOS/360, neither of which had any support for 32-bit addressing. The model 67 was designed to run TSS, IIRC. Where I worked, at Wayne State University in Detroit, we had a duplex (two processor) model 67 that was partitioned to run MVT on one processor and the Michigan Terminal System on the other processor. MTS was fairly popular. It was written at the University of Michigan and I think that there were about a dozen sites that ran it. WSU ran MTS until about the mid-1990s. I don't remember if MTS supported bimodal addressing. -- Tom Marchant The model 65 could be configured to run as a model 67, with virtual memory and 32-bit addressing or as a model 65 without those feature. The MVT half ran in model 65 mode. I believe that 31-bit mode was designed into XA so that the mode bit could be kept with the address. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
