From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave@horsfall.org (Dave Horsfall) Date: Sun, 27 Jul 2014 15:49:47 +1000 (EST) Subject: [TUHS] First Unix that could run on a PDP-11 with QBUS In-Reply-To: <20140727032639.46B6718C0DE@mercury.lcs.mit.edu> References: <20140727032639.46B6718C0DE@mercury.lcs.mit.edu> Message-ID: On Sat, 26 Jul 2014, Noel Chiappa wrote: > That may or may not be true; let me explain. The 11/23 is almost > indistinguishable, in programming terms, from an 11/40. There is only > one very minor difference (which UNIX would care about) that I know of - > the 11/23 does not have a hardware switch register. I recall that there were other differences as well, but only minor. In my paper in AUUGN titled "Unix on the LSI-11/23" it will reveal all about porting V6 to the thing. I vaguely remember that the LTC had to be disabled during the boot process, for example, with an external switch. Then again, I could be thinking of some other weird box to which I'd ported V6. As far as I know, it was the first such port in Australia (if there were others then I never heard about them). -- Dave