test-drb September 2004

test-drb@ccmp.vtda.org

268 participants
648 discussions

by pete＠dunnington.u-net.com

On Sep 29 2004, 0:10, Vintage Computer Festival wrote: > On Wed, 29 Sep 2004, Pete Turnbull wrote: > > > [1] They're not paired as 1+2, 3+4, etc either. The first pair is the > > centre pins, the second pair is the two pins either side of centre, and > > so on, working outwards. > > The third and fourth pairs would not be "so on". They'd be the pairs on > either side of the center, since Orange+White/Orange and Brown+White/Brown > are not split. Er, no, in a USOC-wired RJ45 pair 1 is pins 4+5, pair 2 is pins 3+6, pair 3 is pins 2+7, pair 4 is pins 1+8. You're thinking of TIA 568, where pair 1 is 4+5 (blue), pair 2 is 3+6 (green), pair 3 is 1+2 (orange) abnd pair 4 is 7+8 (brown), as I wrote above the bit you quoted. -- Pete Peter Turnbull Network Manager University of York

21 years, 1 month

simh simulation speed

by RCini＠congressfinancial.com

IIRC from Bob's speech at VCFe2.0, he indicated that simulation speed is effectively unregulated, because why would you want to waste the benefits of a speedy host machine. However, I could imagine that with certain hardware simulations, cycle-by-cycle emulation might be required. On my Altair32 emulator, I have it set to run at the prototypical 2MHz speed (8080A). But, I can unthrottle it and let it run at full speed, which on my Pentium 4/2.8GHz would result in an 8080 running at about 80MHz (+/-). This is accomplished by managing the number of prototypical CPU cycles executed per 10ms timeslice. Rich -----Original Message----- From: cctalk-bounces(a)classiccmp.org [mailto:cctalk-bounces@classiccmp.org]On Behalf Of Tom Jennings Sent: Monday, September 27, 2004 3:24 PM To: General Discussion: On-Topic Posts Only Subject: simh simulation speed I haven't had a chance to get back and debug, but is it true that simh does NOT simulate the target machine's execution speed? I wrote a simple 'sum all words in track N' program for the LGP and it completed as soon as I hit return! It should have taken many seconds... I did RTFM, so no reference to it, but I haven't had time to go look at the source. Got lazy and decided to post instead of research (typical, huh :-)

21 years, 1 month

Harvard vs. vonNeuman

by msokolov＠ivan.Harhan.ORG

spc(a)conman.org (Sean 'Captain Napalm' Conner) wrote: > Okay, figured out why my code didn't work, and it's not due to writing to > the wrong location (although I suspect that still is a problem) but that > under Unix the code pages are marked read-only so of course it core dumped. You do know about -N option to ld, right? That would make an OMAGIC executable whose code is not protected. MS

21 years, 1 month

Marconi catalog

by aw288＠osfn.org

Can anyone use an old Marconi Instruments test equipment catalog? I have an old edition here (NA7) that needs to go away. Inside are the usual picures and descriptions of the gear (much like the big HP catalogs). Of interest to those on this list are the ATE equipments - there are some nice shots and data for their PDP-11 (the original) based test sets. William Donzelli aw288(a)osfn.org

21 years, 1 month

FA: DEC FlIP CHIP boards & more

by rigdonj＠cfl.rr.com

I just finished putting some stuff on E-bay that this group might be interested in including some single height DEC FLIP CHIP wirewrap cards, a HP-12C calculator, a box and manual for the HP-11C calculator and a bunch of ROM and RAM cartridges for the Tektronix 83x Communications Analyzers. Those of you that are making your own cartridges for the Tektronix 124x Logic Analyzers will be interested to know that these cartridges will also fit the 124x LA if you trim the locator keys. See <http://www.classiccmp.org/hp/tek-roms/case-keys.jpg>. I will be adding some core memory boards as soon as I have a chance (probably a couple of days). <http://search.ebay.com/_W0QQgotopageZ1QQsassZrigdonjQQsosortorderZ1QQsosort propertyZ1> Joe

21 years, 1 month

Computer Museum looking for a new home Starting bid: US $99, 000.00 (Reserve not met)

by eric＠rothfus.com

(not sold by me & cross-posted from another list) "The entire Freeman PC Museum is offered for sale. David Freeman, founder of ACP Superstore, has been collecting computers since 1976. As a pioneer in computer retailing Mr. Freeman started early collecting. This collection represents almost 30 years of collecting. To date over 280 computers have been place online at www.thepcmuseum.net. There are approximately 600 computers, calculators, printers, video game consoles in the collection. Not all of the computers have been placed on the website as of yet, but all are included in this sale. Everything is included. Many items in this collection are irreplaceable and no longer available. This collection includes countless software titles, manuals, books, magazines and other computer memorabiia. You could truly display a PC Museum in your place of business with this collection...." http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5125710949

21 years, 1 month

Relay computers - OR functionality

by dwight.elvey＠amd.com

>From: "Ron Hudson" <ron.hudson(a)sbcglobal.net> > >I had, at one point, sat down and tried to devise a JK flipflop out of >relays.. > >I can do a latch... where (in) pulls in the relay and a NO contact >connects >v+ to keep the relay in.. but everything I tried just vibrated... :^\ > >In a relay computer wouldn't one need flipflops for memory? > I thought I'd take on the challenge. Doing a JK with relays. First, define the clocking and, for Sellam, the state of the contacts. I will define relays as numbers and there contacts as O for normally open and C for normally closed. As an example R1C will be one of the normally closed contacts. If this name is used multiple times, it may indicate more than one set of contacts, depending on the optimization used. There will be 4 clocks. It will look as: One cycle of clock. P0 C O C C C C ( Hold clock for R1 ) P1 O C C O O O ( evaluate clock for R1 ) P2 C C C C O C ( Hold clock for R2 ) P3 O O O O C C ( evaluate clock for R2 ) O means open contact at that time and C means closed during that time. The JK flop is composed of two relays, R1 and R2. R2 contacts correspond to the Q and Q* outputs( R2O and R2C ). R1 or R2 by itself would be the coil. I also show the complete path from rail to return, even if it is duplicated at some points. JO and KO are normally open contacts of some other relay that when activated is the logical signal corresponding to J and K. Wiring: Rail to R1O to P0 to R1 to return Rail to R2O to KC to JC to P1 to R1 to return Rail to JC to KO to P1 to R1 to return Rail to R2C to JO to KO to P1 to R1 to return Rail to R2O to P2 to R2 to return Rail to R1O to P3 to R2 to return I would not use a JK flop for a memory array, even if I was using normal relays for the memory. The are too wasteful of contacts and coils. There is some optimization that could be done with diodes as well. One can generate the clocks with relays or some kind of distributor, similar to what is used on a teletype and a variable speed motor. If done with relays, one would need some way to control the speed. It might make sense to invert the signal between the two relays so that regardless of the state, only one relay, on averagel would be on at a time. Dwight

21 years, 1 month

Harvard vs. vonNeuman

by dwight.elvey＠amd.com

>From: "Tom Peters" <tpeters(a)mixcom.com> > >I use a lot of self-modifying code: Perl scripts that generate HTML code! > >Maybe that doesn't count... > Hi Tom Only counts if it then calls the HTML is generates. Dwight

21 years, 1 month

Relay computers - OR functionality

by dwight.elvey＠amd.com

>From: "Vintage Computer Festival" <vcf(a)siconic.com> > >On Mon, 27 Sep 2004, Dwight K. Elvey wrote: > >> In my logic, 'A' would indicated the normally opened contact >> an 'a' would be the normally closed contact for relay A. >> I'll use + to indicate OR and . to indicate AND. > >You already lost me. You may as well have used ! and $ instead of A and >a. > >:) > >P.S. C programming convention (which most people would relate to >immediately) says that next time you should use & for AND and | for OR. > >-- Hi I'm sorry, people doing logic have been using + and . a lot longer than C has been using & and |. I specifically stated what I would use. Look at most any pre-C math book and you'll most likely see the + and . used for OR and AND. These are just symbols until one applies meaning to them. I don't see the issue. One should be able to adapt to different conventions because that is the way things will be represented >from different sources. I adapt and I hope others learn to do it as well. I don't see the issue with using upper and lower case to indicate normally close or normally open? What difference does it make how one represents it? Dwight

21 years, 1 month

MIPS R6000 and R8000 manuals, real 680x0, and others...

by jfoust＠threedee.com

I recently had an email conversation with Ralf Baechle <ralf(a)linux-mips.org> regarding some manuals he'd scanned: > Yes, if you have other old manuals, I will pass them > along to other classic computer archivists. Did you > can them yourself or did you collect them from the net? Both. The ones I scanned myself are the R6000 and R8000 manuals - extremly rare documents. I managed to get hold of them while still working for SGI and only recently got permission from MIPS Technologies to publish the manuals. The two manuals would be the R6000 and R8000 manuals. They're available via ftp on bacchus.net.dhis.org:/pub/mips/ I also scanned manuals for the WD33C93 and WD33C95 SCSI chips. Those however I don't have permission to publish, so they're not on my ftp server. And of course a whole bunch more that I downloaded from random places on the net over the past decade ... I btw convert my scans into PDF files for which nice reader software is available. [...] I found proper 68000, 68020, 68030, 68040 and 68060 manuals on the net, that is "real" pdf files, not scans. These are the URLs: http://www.freescale.com/files/archives/doc/ref_manual/M68000PRM.pdf http://www.freescale.com/files/archives/doc/ref_manual/M68000PRMER.txt http://bellota.ele.uva.es/~jesus/datasheets/motorola/68000UM.pdf http://dac.escet.urjc.es/docencia/Micros/DataSheet/CPU/motorola/68020um.pdf http://dac.escet.urjc.es/docencia/Micros/DataSheet/CPU/motorola/68060um.pdf http://dac.escet.urjc.es/docencia/Micros/DataSheet/CPU/motorola/060d.pdf http://www.tornado.nsk.ru/support/docs/68030UM.pdf http://www.tornado.nsk.ru/support/docs/68040um.pdf And this one is scanned but given the age I wasn't exactly expecting a Postscript or PDF file ... http://bellota.ele.uva.es/~jesus/datasheets/motorola/6809.pdf Ralf

21 years, 1 month

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test-drb September 2004