test-drb

test-drb@ccmp.vtda.org

101090 discussions

by lists＠loomcom.com

I don't suppose anyone has a copy of the CDC 9429 floppy drive maintenance manual they'd be willing to scan for me? I have reason to believe that the CDC 9428 and 9429 are identical except that the 9429 is jumpered for 80 tracks and the 9428 is jumpered for 40 tracks... but I'm not 100% sure. I do have a copy of the 9428 maintenance manual, thanks to Bitsavers, but having the 9429 manual would put my mind at ease lest I follow the alignment procedures from the 9428 manual and screw something up. -Seth -- Seth Morabito seth at loomcom.com

9 years, 9 months

Decmate 2 error codes

by pdaguytom＠gmail.com

Just picked up a Decmate 2 and have managed to get a monitor, keyboard and boot disk (I think) setup for it, but when I attempt to boot it, I'm getting alternating error codes 17 and 19(on different boot attempts). I've searched and found some of the startup error codes but not these particular ones. Anyone know where I could find such a list? Thanks, Tom

9 years, 9 months

Facit 4070 to PC interface

by chd＠chdickman.com

Has anyone ever worked up a PC parallel port to Facit 4070 paper tape punch interface? I found one on a Swedish website. The punch parallel input looks like it is TTL compatible, but I can't find anything in the documentation that describes the input voltage specifications. Chuck

9 years, 9 months

CMU-CS-78-104

by aek＠bitsavers.org

Came across this in some stuff I got last week and thought it was pretty interesting http://bitsavers.org/pdf/cmu/cs-tr/CMU-CS-78-104_Impact_of_Implementation_D…

9 years, 9 months

HP breakup... Website & ftp being trashed ... save what you can

by swiftgriggs＠gmail.com

If you care, you might want to check out: ftp://ftp.hp.com:/pub/alphaserver/firmware I'm always updating firmware on older alphas and I've noticed this site has undergone some changes lately. I've also noticed that HP's web sites have been absolutely trashed for a couple of years now. However, now many alpha related searches return 0 results on most of their portals. When you do find something, it's often a dead link. Many of the Tru64 pages are all a broken link, broken CSS, shambles. Anyhow, my trust in HP is at an all-time-low (more than I even knew was possible after I got my whopping $26 dollar settlement for them ripping folks off on ink cartridges and getting class-action-sued for it). Unsurprisingly, they can't even run a website anymore, and even the FTP site seems to be feeling the shake up (directories moving around, things obviously undergoing some major changes). So, you might want to grab whatever you need off the post-Fiorina walking corpse of HP before they go full zombie and eat their own brains and lose everything. There are patches, firmware etc... many things their management would probably remove if they were literate enough to know they still had them online in an undamaged form (folks so often forget about FTP). -Swift

9 years, 9 months

PDP-11/05 microcode dump?

by jnc＠mercury.lcs.mit.edu

> From: Mattis Lind > I'll check all PROM chips on both board sets tomorrow. Check out the Computer History wiki Web page first; I looked at a couple of boards, and added all the chip types I could find. DEC used a vast variety, it seems! Noel

9 years, 9 months

PDP-11/05 microcode dump?

by jnc＠mercury.lcs.mit.edu

> From: Mattis Lind > What about compatibility between different revisions? I.e. Is it > possible to mix DataParh board and Control board from different > revisions with different microcode? Well, I don't recall seeing any mention of compatability in the manuals, but that is not definitive either way. I had a look at the two versions of the data path board, and it seems to me that they are basically identical in their interface and function, so that either version would work with any control board version. I looked at the interconnects with i) the other CPU board (on the C-F connectors), and ii) the front console (through the Berg connector), and as far as I can see, both boards use the same interconnects. I didn't track down every last pin, and check them all, but I checked many, many pins, and all the ones I checked were the same. The two versions don't seem that different, internally. The PROMs are the same on the two versions of the data path board, for what that's worth - which is probably not that much. (The PROMs on the data path board don't contain any microcode at all; that's all on the control board.) One major difference is that the register file chips on the older board (which have tri-state outputs, and use that to do a mux) have been replaced by different register file chips, and real mux chips; however, the two versions should work identically. There are differences in the area of the serial line clock, but those should be immaterial. There are some other minor differences, but again, it seems like they should also work identically. So, that's the source of my conclusion that the two versions of the data path card are functionally identical, and can be interchanged. Noel

9 years, 9 months

PDP-11/05 microcode dump?

by jnc＠mercury.lcs.mit.edu

> From: Steven Malikoff > I was lucky to find an original 11/05 print set dated 1973. For what > it's worth, the microcode listing in my doc is Revision B Do note that a lot of the PROMs on those boards aren't actually 'microcode', and aren't covered in that listing. For instance, on the M7261 (control) board, there are 7 which aren't 'microcode' (list drawn from the 11/05 article on the Computer History wiki): A01A2 = E12 = Bus Request -> Grant processing A02A2 = E30 = Internal address decode (first stage) A07A1 = E68 = Internal address decode (second stage) A09A1 = E69 = Internal address decode (second stage) A09A2 = E101 = Branch utest service A13A1 = E90 = Internal interrupt acknowledge A14A1* = E100 = Console switch control and 10 which are: A04A2 = E92 = Next instruction (high bits) A05A2 = E93 = Processor Status Word control A07A2* = E95 = Bus control A10A2 = E103 = Next instruction (low bits) A11A2 = E104 = ALU operation select A12A2 = E105 = Branch utest A13A2 = E106 = Multiplexor control A14A2 = E107 = Bus control A15A2 = E94 = ALU control A16A2 = E96 = Miscellaneous And I haven't included the 11 PROM chips on the M7260 (Data paths) board, none of which are 'microcode'. So those 'microcode' listings only cover about 1/3 of the PROM chips in the CPU; so one can't use just the microcode revision level to tell you what's what. E.g there are two chips different between the C and E etch levels of the M7261: A07A2 and A14A1 (marked with a '*' above); one is 'microcode', one isn't. BTW, when you say that the microcode listings in your 1973 print set are "Revision B", are you referring to the "Microprogram Flow", "Microprogram Symbolic Listing", or "Microprogram Binary Listing", because they can be at different revision levels (given in the box in the extreme lower right corner)? E.g. the ones in the KD11-B prints in the GT40 print set (dated February 1973) are 'B', 'C' and 'C', respectively; the hard-copy set I have (not dated explicitly, but apparently mid-1972, given the modification date on the 'Index' sheet) has 'B', 'B' and 'B'. > it is *exactly* the same printout as in the the Bitsavers doc Revision > C You mean the July 1976 set, the ones with microcode revision levels (as above) of 'C', 'E', and 'E', right? That is M7261 etch revision 'F', which uses quite a few different PROM chips >from the earlier ones, so I'd be fairly surprised if the microcode was actually identical. I think you'd have to look at every bit to be sure; the data on which chips changed, here: http://gunkies.org/wiki/PDP-11/05#Control_PROMs would allow anyone who wanted to actually do that to focus in on specific columns of the microprogram to look for differences. (In fact, the 'F' etch rev has one less PROM chip than the 'E' etch rev, but I suspect - i.e. I haven't checked the exact function of each chip on those etch levels - that it's not a micro-program chip, though: there's one less 32x8 PROM chip, and those are generally used for control functions, the microprogram chips are all 256x4.) Noel

9 years, 9 months

Interfacing with HP-HIL

by cmhanson＠eschatologist.net

Has anyone used any modern hardware to interface with HP-HIL gear? (HIL is Human Interface Link, not to be confused with HP-IL.) I?d like to interface an HP 46085A Control Dial Box <http://www.hpmuseum.net/display_item.php?hw=684> with my Mac via USB. But before I go any further in this?I?ve already put a bunch of effort into trying to get it to work?I realized I should probably ask here to see if anyone else has done it. Has anyone? HP-HIL uses what *should* be a pretty basic serial protocol with available docs. (Thanks, Bitsavers!) The only odd things about it are (1) a data rate of 100Kbps (rather than say 115Kbps) and (2) the use of 12/O/1 framing (rather than say two 8/E/1 frames per packet and (3) a 12V supply line for what?s otherwise a TTL-compatible bus. Getting the actual host interface IC is just about impossible without removing it from existing equipment, and the client interface IC doesn?t really seem like it would act as a host. The weird framing means virtually no common UART will work, and the data rate means something like an Arduino only has 160 cycles/bit to work with. It looks like I might be looking at either using either an Arduino or a CPLD to implement a 12/O/1 UART to talk to the control dial box, and using a second Arduino to communicate with that (via a parallel interface) to actually implement the USB HID via the builtin HID stack functionality on some models of Arduino. -- Chris

9 years, 9 months

When did Memory- and IO Protection Emerge (Esp. in Minis)?

by erik＠baigar.de

Dear Experts, during discussing the Rolms I came accross the following question: What was the first (Minicomputer) architecture which offered memory- and IO protection? I'd define the minimum requirements as: - Existence of a superuser mode (Rolm calls this Executive mode) - Existence of a user mode (With at least two users, Rolm offers 4) - In superuser mode, IO and memory protection for each user can be set up individually. - Any access violation is trapped and handeled by superuser code. - Of course commands for mode switching and setting up the memory and IO ranges must exist. I have got a real machine (Rolm 1602) having this implemented and dating from 1975. A document on this "Access Protection Module" as Rolm calls it also is dated 1975. It consists of a microcode module which realizes an extension of the 16 bit Nova instruction set and an additinoal CPU module, taking care of the new modes and supervising the IO- and memory accesses. My question is not regarding virtual memory memory, but regarding protection (IO and memory) to ensure capsulation of indivitual processes - not necessarily for multi user environments but e.g. for safety critical applications... Probably OS/2 in 1987 was one of the first home computer OSes to support memory protection (how about IO protection?), BSD on some Digital PDP-* was earlier (1977?) but still after the 1602. Any hints out there on other "Mini" architectures of that era having someting similar? Erik.

9 years, 9 months

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb