From terry@spcvxb.spc.edu Wed Aug 17 06:38:58 PDT 1994 Article: 2765 of vmsnet.pdp-11 Newsgroups: vmsnet.pdp-11,alt.sys.pdp11 Path: nntp-server.caltech.edu!netline-fddi.jpl.nasa.gov!elroy.jpl.nasa.gov!swrinde!gatech!europa.eng.gtefsd.com!MathWorks.Com!solaris.cc.vt.edu!spcuna!spcvxb!terry From: terry@spcvxb.spc.edu (Terry Kennedy, Operations Mgr.) Subject: Re: PDP-11/73 Cabling Questions Nntp-Posting-Host: spcvxa.spc.edu References: <32peitINNp95@umbc8.umbc.edu> <32qtl9INN2sm@umbc8.umbc.edu> Sender: news@spcuna.spc.edu (Network News) Organization: St. Peter's College, US Date: Wed, 17 Aug 1994 04:25:24 GMT Message-ID: <1994Aug17.002524.1@spcvxb.spc.edu> Lines: 44 Xref: nntp-server.caltech.edu vmsnet.pdp-11:2765 alt.sys.pdp11:264 In article <32qtl9INN2sm@umbc8.umbc.edu>, rdavis4@umbc.edu (davis robert) writes: > The CPU is an M8190 AB (KDJ11-BB); according to the field service listing > of modules that was posted here, this is a J11 CPU, 15 MHz, with 2 boot > and diagnostoc ROMs and FPJ11 compatibility (warm floating point but will > accept an FPA). What is "warm floating point"? It means that the base processor chip (the J11) knows how to do floating point math, but isn't very good at it 8-). For floating-point-intensive uses, it's recommended that you add the FPJ11 floating point accelerator. > Im guessing that since this CPU runs at 15 MHz and not 18 MHz that it > is not an 11/83 or higher. This is confusing, so bear with me. There are 4 basic board families that implement Q-bus CPU's with the J11. They are the KDJ11-A (11/73, dual card intended for OEM's), KDJ11-B (11/73 [see - I told you it was confusing!] and 11/83, where both are a quad card but the '73 runs at 15MHz and has no factory FPA and the '83 runs at 18MHz and comes with an FPA), KDJ11-C/D (11/53, in various forms. The only common ones are the .5 and 1.5MB on-board memory 15MHz units, although there is an 18MHz flavor with S-box handles for the DECserver 500/550), and KDJ11-E (11/93, 2 or 4MB on-board memory, FPA). As you can see, there are two different versions called the 11/73. You have the one that uses the same base card as the 11/83. Further confusing the issue are the large number of bugs in the CPU and FPA chips in early releases of the boards, causing you to find "11/83" boards in the field that have no FPA. > The memory board used is an M7751 CF. What is the difference between > this and the CA option type board (listed as 4MB 22-bit parity/CSR MOS > RAM)? Are they they the same thing? Normally the second letter of the suffix indicates a model variant, but on memory boards it indicates the vendor of the RAM chips on the board. In this case, -CA means "no vendor specified" - it's the spec for the module, and -CF means the board was built with Hitachi chips. > Also, does anyone know anything about an M3107 board (for serial ports)? > This isn't listed in the field guide to modules. Yes. It's a DHQ11. Terry Kennedy Operations Manager, Academic Computing terry@spcvxa.spc.edu St. Peter's College, Jersey City, NJ USA +1 201 915 9381 (voice) +1 201 435-3662 (FAX)