On 8/19/20, Clem Cole <clemc(a)ccc.com> wrote:
small update ... see below..
On Wed, Aug 19, 2020 at 1:39 PM Paul Winalski <paul.winalski(a)gmail.com>
In the IBM System/360 world, the first machine
with Dynamic Address
Translation (DAT, the hardware that implements virtual->physical
address transiation via page tables) was the S/360 model 67.
Called the Data Address Translator (DAT) box. I still have my 'TILT' deck
which is an IPL program that used diagnose instructions to spell TILT in
the lights on the DAT box and ring the console bell, which on a 360 was a
BTW: the 67 had 8 32 bit TLB entries, built out of ECL flip-flops.
The various OS/VS variants for S/370 were way late. IBM was forced to
release the models 155 and 165 before OS/VS was available. The
decided to take the opportunity to stick it to the third-party leasing
companies. The S/370 models 155 and 165 were released without DAT
boxes. The third-party leasers gobbled them up. The third S/370, the
model 145, had to be released with the DAT hardware and microcode
because the IBM 1400 emulator needed it. Then OS/VS was finally
ready. For the model 145 DAT support just worked. For the 155 and
165, a DAT box could be added to turn them into the 155-II and 165-II.
If you leased your machine from IBM, you got the upgrade for free. If
you had bought the machine, you had to pay through the nose to get a
IBM OS to use it was CP/67, the virtual machine forerunner of VM/370.
Careful, TSS used it first actually and shipped before CP/67 - but it had a
number of issues.
CMU would work to fix them and Michigan would start and rewrite, creating
MTS (which was not an IBM product but TSS was and shipped into the early
I forgot all about TSS.
I just did a review of a book that I'll find out
when it supposed to hit
the streets by some tech historians in the UK. I reviewed the chapter
where CTSS begets, Multics and TSS, beget UNIX and MTS respectfully.
Basically the name of the chapter is the rise of idea of timesharing.
[No worries, the DEC world is in the book also, but follows a different
thread - this is looking at the fight at IBM and GE between commercial
batch and timesharing].
GECOS was GE's commercial batch OS, IIRC. Dartmouth Time-Sharing
System (DTSS) ran on the GE 635.