rschuh wrote:
The smaller systems, the 360-20 and 360-30 had a 1401 emulator mode. It was=
  a h/w or mc based feature. I don't know whether larger machines had it. Th=
ere was also a 1410 emulator mode on the -40. I do not know of any 1401 sup=
port that ran under DOS, but my DOS experience is miniscule.=20

360/30 had 1401 microcode emulation ... actually 360/30 front panel switch that
selected 360 microcode "emulation" (since 360 was implemented as microcode on
360/30) and 1401 microcode "emulation"

recent stories in ibm-main mailing list about univ. getting 360/30 to replace
1401 (in staged processs of replacing 709/1401 combo with 360/67 which was 
to run with tss/360). IBM Mainframe: 50 Years of Big Iron 
Innovation Book on Poughkeepsie

709 ran ibsys, tape->tape, a lot of fortran student jobs. 1401 was front-end 
handling card reader-> tape & tape->printer/punch for the 709 ... with tapes 
manually moved from 1401 tapes and 709 tapes.

Even tho the 1401 "MPIO" program ran perfectly fine on 360/30 in 1401 emulation
mode (switch to emulation mode and boot MPIO from 2504 reader, effectively same 
if running real 1401) ... I got a student job to re-implement it in 360 ...
I got to design my own monitor, interrupt handling, device drivers, storage 
console interface, etc. Eventually was 2000 card program with assembler
directive that would either generate a "stand-alone" program or
version that ran under os/360. Stand-alone version took approx. 30
minutes to assemble ... version that would run under os/360 took
nearly an hour to assemble since it took approx. five minutes
elapsed time per DCB macro.

The univ. eventually got a 360/67 ... but since tss/360 wasn't ready, it
spent nearly all its time running os/360 as 360/65. 360/65 (and 360/67)
had 709x microcode emulation support (as opposed to 1401 emulation available
on lower-end 360s).

Last week of January 1968, three people from the science center ... some
past posts

came out to the univ. to install (virtual machine) cp67. at the time, cp67 
really up to the univ. os/360 production workload ... but I got to play with
it quite a bit on weekends. some discussion detailed in these posts: Book on Poughkeepsie Book on Poughkeepsie

misc. other recent related posts in ibm-main mailing list thread IBM Mainframe: 50 Years of Big Iron 
Innovation Book on Poughkeepsie Book on Poughkeepsie

360/30 functional characteristics has reference to 1401/1440/1460 compatibiilty
feature (GA24-3255)

1401 simulator for os/360 contributed program:

it might not have been all the difficult to port above to CMS???

1401/1440/1460 Emulator Programs (under dos/360)

360/65 functional characteristics
360/67 functional characteristics

lists optional feature: 709/7040/7044/7090/7094/7094II Compatibility

single processor 360/67 was nearly identical to single processor 360/65 except
with addition to virtual address translation hardware.

40+yrs virtualization experience (since Jan68), online at home since Mar1970

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