From mboxrd@z Thu Jan 1 00:00:00 1970 From: jnc@mercury.lcs.mit.edu (Noel Chiappa) Date: Thu, 15 May 2014 16:56:59 -0400 (EDT) Subject: [TUHS] Unix on an 11/23 (Was: Work I've done with a PDP-11 simulator) Message-ID: <20140515205659.1FED918C0C0@mercury.lcs.mit.edu> > From: SPC > I'll keep a reference of this message and try it as soon as possible... No rush! Take your time... > the disruptive fact (in terms of time) here is to put up-to-date both > the PDP-11/23-PLUS and RL02. My apologies, I just now noticed that you have an 11/23-PLUS (it is slightly different from a plain 11/23). I am not very familiar with the 11/23-PLUS (I never worked with one), but from documentation I just dug out, it seems that they normally come with the MMU chip, so we don't need to worry about that. However, the FPP is not standard, so that is still an issue for bringing up Unix. In fact, there are two different FPP options for the 11/23-PLUS (and, actually, for the 11/23 as well): one is the KEF-11AA chip which goes on the CPU card (on the 11/23-PLUS, in the middle large DIP holder), and the other is something called the FPF-11 card, which is basically hardware floating point (the KEF-11A is just microcode), for people who are doing serious number crunching. It's a quad-size card which has a cable with a DIP header on the end which plugs into the same DIP holder on the CPU card as the KEF-11A. They look the same to software; one is just faster than the other. Anyway, if you don't have either one, we'll have to produce a new Unix load for you (not a big problem, if it is needed). Noel