On Sat, 2026-02-07 at 14:25 -0600, Jay Jaeger via cctalk wrote: > > Initially, on the 360s, you could push buttons on the console, and > > have one > > or more 14xx series machines if you had enough memory. perhaps > > with 370s > > too. > > Don't know about that one way or the other - if there were a button, > I > suppose it would have been an IML button of some sort to load the > microcode assist.
On a 360/30 with 1401 microcode that I used in 1967, one would first load the small "Compatible Initialization Deck" (about fifty cards). Then set the microcode address to 1402 (1401?) to load from cards, of 1729 (I'm confident I remember this correctly) to load from tape, then push the IPL button. I don't remember what microcode addresses one would use to run it as a 360 because the only 360 program I ever used was SORT --- which was much faster than 1401 SORT 7 because the 240x tape drives could (and did) do read reverse — but I ran 360 SORT only once or twice. The 360/30 was a temporary stopgap because the company was converting all its Autocoder programs to COBOL in anticipation of replacing the 1401s with Burroughs 2500s, not 360s. So I mostly did 1401 COBOL compiles followed by Autocoder assemblies. They didn't use 360 COBOL because some processing centers still had real 1401s. They'd already tried Honeywell 200s using using Liberator and Easycoder and weren't satisfied. The processor was OK but the unit-record peripherals, especially the drum printer, were crap.
