From mboxrd@z Thu Jan 1 00:00:00 1970 From: paul.winalski at gmail.com (Paul Winalski) Date: Wed, 19 Aug 2020 18:09:29 -0400 Subject: [COFF] [TUHS] Memory management in Dennis Ritchie's C Compiler In-Reply-To: References: <20200817192715.22D9518C09E@mercury.lcs.mit.edu> <20200817193050.GC11413@mcvoy.com> Message-ID: On 8/19/20, Clem Cole wrote: > small update ... see below.. > > On Wed, Aug 19, 2020 at 1:39 PM Paul Winalski > wrote: > >> 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 > fire alarm. > > 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 DAT box. >> The only >> 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 > 1980s). 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. -Paul W.