From coff at tuhs.org Wed Apr 1 13:20:47 2026 From: coff at tuhs.org (Warren Toomey via COFF) Date: Wed, 1 Apr 2026 13:20:47 +1000 Subject: [COFF] Problems with TUHS and COFF mailing lists Message-ID: Hi all, I'm back from a 3 1/2 week overseas holiday. Of course, partway through the trip the TUHS server "minnie" decided to hit 0% free disk space. I was able to clean things out remotely using a tablet and Bluetooth keyboard. However, since then I've had a few e-mails saying that submissions to TUHS and COFF have gone to /dev/null. I haven't deduced the issue yet. So, if in the next few weeks you post to TUHS or COFF and you don't see your posting, please e-mail with as much details as you can provide; a copy of the logs from your mail server would be wonderful! Thanks, Warren From coff at tuhs.org Sat Apr 4 23:41:35 2026 From: coff at tuhs.org (Douglas McIlroy via COFF) Date: Sat, 4 Apr 2026 09:41:35 -0400 Subject: [COFF] GE-635 GECOS? Message-ID: Clem wrote > Check out > https://www.multicians.org/ge635.html > From what I can tell GCOS has been lost to time The Multicians timeline shows Bell Labs joining the project after GE was chosen as the vendor. This may be the date of some formal agreement. However, the Labs was in on the final confirmation of GE. IBM had been ruled out over the issue of virtual memory. GE was happy to offer a VM variant of the 635. In contrast, IBM's chief architect, Gene Amdahl, adamantly maintained that VM was unacceptably inefficient. When it became clear that GE was winning, IBM revealed Gerrit Blaauw's 360 model 67 with VM, which had been kept under wraps. The option was considered, but found to offer no advantage from a programming standpoint. Nevertheless, time-sharing on the IBM machine made it into the field well before Multics; MTS, the Michigan Terminal System, went live in 1967. the same year that GE delivered the 645. A completely unsung project at Bell Labs during the Multics era was Joel Sturman's GUTS, GE User Time Sharing on the 635. Joel built this without any specific kernel support. I'm sorry I don't know more about it, in particular how it did scheduling. Way off topic, but apropos of the 360 vs contemporary 36-bit machines, a member of the design team for the Apollo mission once told me that it was fortunate they were using IBM 700/7000 equipment rather than the new-fangled 360s. 36-bit floating-point precision was just enough to calculate trajectories to the moon without resorting to slow software double precision. The 32-bit floating point of the 360 would have forced the slow alternative. I suspect also that hex rounding would have exacerbated the difference. Doug