a 2540 card read/punch was normally addressed as 00C/00D, a 1401 class printer as 00F. if you had multiples, they were typically 01C/01D and 00E.
I heard, but never saw that if you didn't like the next operator, you taped over the tabs that stop the cards on a 2501 card reader and the cards would to shooting across the room. Early on, there was a TOS as well as DOS that would run from one tape drive. I tried to get a copy, but as just an operator, unable to. i wonder if any copies exist. we briefly had a 3rd party drive for 1311 disks, which was cool because it had binary lights to show what track the head was on. We also had a 3rd party extra 32k memory expansion for a model 30. they pulled that and upgraded to a model 40 to get the bigger memory. The memory was needed for sort tables when sorting checks (it was a bank). <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free.www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Sun, Feb 8, 2026 at 9:19 AM Paul Koning via cctalk <[email protected]> wrote: > > > > On Feb 7, 2026, at 3:57 PM, Donald Whittemore via cctalk < > [email protected]> wrote: > > > > My Dad was a 360 operator, as was I. I will swear he set the load unit > as 00C and hit load. In the card reader was something labeled CID. > Compatibility Initialization Deck. Was less than 1/2 inch of cards. I > believe it put the Mod 30 (or 40) into pure 1401 mode. No 360 code running. > > You can certainly IPL off the card reader, though I've never done it. I > did see the 360 model 44 "emulator" deck, which is loaded that way using > the "Emulator IPL" button, into a separate block of memory invisible during > normal execution. It's vaguely like Alpha PALcode, I guess. > > That deck was a standard IBM 360 object program file, with the channel > program on the first card loading all the pieces to the right places. > > No idea what this CID was. It could be simply a "bare metal" ordinary 360 > program, or a 360 program combined with helper microcode. > > paul > > -- --Carey
