On 9 December 2013 19:14, J R <[email protected]> wrote: > - The first word of the TCB proper, ie. +0 is TCBRBP, but this offset is > "fixed by architecture"!
I think a number of these comments on doubtful sounding fields came about only because of the microcoded assists that arrived in the days of MVS/SE. More recently, SIE and all its baggage may also provoke this comment. Clearly fields like the old and new PSWs in low storage have been "fixed by architecture" <forever> but the architecture knew nothing of TCBs or RBs on System 360 or early 370s > Back in the early '70s, when I first noticed the IKJTCB macro, I speculated > that TSO was the first component to > "macroize" the DSECT, and hence gave it the IKJ prefix. I never found out > the truth but it is possible that, up until that > time, offsets fixed by architecture were hard-coded rather than named. That's my conjecture also. What we need is some source code from an OS/360 version before 20.x, which is when TSO became available. But of course some core of TSO may well have been in even earlier OS versions; it seems most unlikely that TSO sprang fully formed and ready to ship (FSVO "ready") from SDD in 1971 or so. Someone must have that old round tape in the attic somewhere. I know I did... Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
