test-drb February 1999

test-drb@ccmp.vtda.org

178 participants
709 discussions

by cswiger＠wilma.widomaker.com

Here's a semi-interesting page of quasi-historical importance about uP's of the past. It probably doesn't jive with the classiccmp list view of reality, but discusses 40xx's, and {non-authoritatively} answers one members question about the uP in the Voyager probe: "Apart from the COSMAC microcomputer kit, the 1802 saw action in some video games from RCA and Radio Shack, and the chip is the heart of the Voyager, Viking and Galileo " http://www.cs.uregina.ca/~bayko/cpu.html We especially like the 2nd IEEE Computer article in Apendix E. Chuck cswiger(a)widomaker.com

25 years, 5 months

ALTAIR stuff (was Re: E-Over Pay strikes again! originalAltairdisk sells for... )

by allisonp＠world.std.com

<Well . . . I'd make the observation that while the ALTAIR was certainly <built in the mid 1970's, several of the other machines to which you refer <were not, not were the "mini-floppy" drives which later became common. Ok, lets get on the same page. I built altair serial number 200 in 1975, January to be exact. from there I can elaborate but I think being there and using/building many allows me historical accuracy. <In the mid-'70's, both ribbon cable and IDC connectors were quite costly b <comparison with up-to-then common labor intensive hand wiring. As the Gee I posted something to that effect. A quote of mine from the mail you quoted. <> Believe it. The cable was hand wired and IDC in the mid '70s was really <> new, expensive and not quite ready for pimetime. IDC was more an early <> 80s item brought to the party. <economies of scale took effect, ribbon and the associated connector <mechanisms became both cheaper and more reliable, so that, by the time the More reliable yes, reliable no. Testing at DEC done in the QA labs put the average IDC connector as decaying contact resistance and sometime outright failure in the 10-20 insertion/removeal cycles. The more common D25 or D37 connector was usually 5-10 time better in number of operating cycles. Their conclusion was for external connectors where cables may be moved/changed often the D9/15/25/37 connectors were far better choice. For internal cables where likelyhood of being cycled was lower the IDC connectors were accetable. <mini-floppies were accepted, the associated ribbon cable hardware was <firmly intrenched in the market. The plastic (T&B Ansley in this case) <ribbon cable connectors were not the best available. The old 8" drives ha <enough signals which were used early in the game that the 50-conductor <cable became the standard as opposed to the 34-pin, which could easily <handle the operation of a drive once the later-accepted conventions were i <place. minifloppys accetance was in the 77-79 time frame and IDC was used but considered "cheaping out". <At the time of the ALTAIR, these conventions were not yet in place. That's not news to me. If anything I'd suggested that was exactly the case. I'd seen a great amount to standards (pseudo standards) shift from mid '70s to the mid 80s. One well known one was the S100 bus itself. Allison

25 years, 5 months

ALTAIR stuff (was Re: E-Over Pay strikes again! originalAltairdisk sells for... )

by edick＠idcomm.com

Well . . . I'd make the observation that while the ALTAIR was certainly built in the mid 1970's, several of the other machines to which you refer were not, not were the "mini-floppy" drives which later became common. In the mid-'70's, both ribbon cable and IDC connectors were quite costly by comparison with up-to-then common labor intensive hand wiring. As the economies of scale took effect, ribbon and the associated connector mechanisms became both cheaper and more reliable, so that, by the time the mini-floppies were accepted, the associated ribbon cable hardware was firmly intrenched in the market. The plastic (T&B Ansley in this case) ribbon cable connectors were not the best available. The old 8" drives had enough signals which were used early in the game that the 50-conductor cable became the standard as opposed to the 34-pin, which could easily handle the operation of a drive once the later-accepted conventions were in place. At the time of the ALTAIR, these conventions were not yet in place. Dick ---------- > From: Allison J Parent <allisonp(a)world.std.com> > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: Re: ALTAIR stuff (was Re: E-Over Pay strikes again! originalAltairdisk sells for... ) > Date: Saturday, February 13, 1999 10:16 PM > > > <I'm not sure you're right about the assertion that 37 is enough. Maybe, > <but the old drives used more signals than the later ones. > > At this point I'd say this. I was there and used then first products. > I even hand made cables. The oldest 5.25 floppies didn't used the full > 34 pins and the 8" drives didn't either. Many of the pins in the 8" case > were used in exchange for others but the odd pins in both 8" and 5" were > all ground and you didn't have to use all of them. the latter being the > common case. > > the best example of this is the DEC VT180 CP/M machine D37 on the back of > the box to a DB25 on the drives. The drives were SA400L or tandon TM-100. > > <The shielded cables using the DC37 connectors certainly were more durable > <than the IDC50 types one often sees, but the cable hardware in the ALTAIR > <box certainly was the cheapest available. I doubt it was any more solid > <than the IDC types. > > Believe it. The cable was hand wired and IDC in the mid '70s was really > new, expensive and not quite ready for pimetime. IDC was more an early > 80s item brought to the party. > > I have the small but significant advantage in that I was old enough to have > been in the engineering business over 6 years before the altair. So I got > to "be there and see there" alot. That and I bought an early Altair > and helped a few business and hardy hackers build and get theirs going. > > Allison

25 years, 5 months

FS: IBM PS/2 model 50 or 50Z power supplies (set of 2)

by rhblake＠bigfoot.com

I have 2 power supplies for the PS/2 50 series of computers, as one unit to get rid of. Both are from working units. One has a red paddle, one white. One is from a 50 and one from a 50Z, but are interchangeable. The set of 2 goes for $5.00 to the first to claim them, plus the applicable USPS shipping. The two weigh about 6-7 lbs. USA and APO/FPO only please. Please include your postal zip code so I can reply to you with a shipping amount. The units are located in zip 40144. Money orders only please.

25 years, 5 months

ALTAIR stuff (was Re: E-Over Pay strikes again! original Altairdisk sells for... )

by allisonp＠world.std.com

<drives, normally packaged externally to the cardcage, was most often a <50-pin flat cable, though a 37 could have handled the task if you didn't <mind that there was not a ground for every signal. The early FDD's were True. <typically hard sectored and used more signals than were required by the <later models. Not always true. If the FDD internal data seperator was used hard sector added 0 (sector holes in same cylinder as hub) or one line (sector holes at perimeter) depending on model. <The insides of the ALTAIR FDD box were not simple and clean like their <successors. Not really. It was pretty vanilla. the board set was a horror. ;) Allison

25 years, 5 months

ALTAIR stuff (was Re: E-Over Pay strikes again! original Altairdisk sells for... )

by allisonp＠world.std.com

<I'm not sure you're right about the assertion that 37 is enough. Maybe, <but the old drives used more signals than the later ones. At this point I'd say this. I was there and used then first products. I even hand made cables. The oldest 5.25 floppies didn't used the full 34 pins and the 8" drives didn't either. Many of the pins in the 8" case were used in exchange for others but the odd pins in both 8" and 5" were all ground and you didn't have to use all of them. the latter being the common case. the best example of this is the DEC VT180 CP/M machine D37 on the back of the box to a DB25 on the drives. The drives were SA400L or tandon TM-100. <The shielded cables using the DC37 connectors certainly were more durable <than the IDC50 types one often sees, but the cable hardware in the ALTAIR <box certainly was the cheapest available. I doubt it was any more solid <than the IDC types. Believe it. The cable was hand wired and IDC in the mid '70s was really new, expensive and not quite ready for pimetime. IDC was more an early 80s item brought to the party. I have the small but significant advantage in that I was old enough to have been in the engineering business over 6 years before the altair. So I got to "be there and see there" alot. That and I bought an early Altair and helped a few business and hardy hackers build and get theirs going. Allison

25 years, 5 months

ALTAIR stuff (was Re: E-Over Pay strikes again! original Altair

by allisonp＠world.std.com

<Do you mean that the various systems that used the 37-pin D-sub actually <used the same pinout? I was of the impression that there was no standard <for it (before the IBM PC created a defacto standard in 1981), so I <assumed that the IBM, DEC, and Xerox stuff probably used entirely unrelate <pinouts. They all used he same connector... none wired it the same that I know of. Allison

25 years, 5 months

Apollo memory boards seen

by ss＠allegro.com

Hi, I saw a bunch (10?) of Apollo memory boards (4 MB?) at WeirdStuff Warehouse (http://www.weirdstuff.com), which is located in Sunnyvale, CA. The boards are in the "As-Is" section, and are $10/each, and are about 4 or 5 inches on each side. SS

25 years, 5 months

SunOS 4.0.3

by fmc＠reanimators.org

Lawrence LeMay <lemay(a)cs.umn.edu> wrote: > It looks like the last version of SunOS that I can run on a Sun 1/100U > is version 4.0.3, however i'm not sure if I have enough ram to use that > version. It looks like I can only add 2 ram boards, and all I have > are 1Meg ram boards... You could probably run any earlier SunOS. I used to run 3.5 on my 2/120 and 2/50, but I had 4MB in each, later 7MB in the 2/120. I also remember getting X11R4 to build and run on the 2/120 under 3.5, but can't remember how much memory I had at the time, just that it took 18 hours to build. I'm thinking 3.5 would be lighter than 4.0.x. I remember thinking about getting 4.0.x for my 2/120 so it would support SCSI disks (besides ST506 and ESDI disks attached via Adaptec ACB4000 and Emulex MD21) and deciding against it. > The Sun 1/100U does not have any way to connect peripherals such as > hard drives, so the unit will have to be booted from the network. > I guess its almost time for me to brush up on tftp protocol, assuming > I can find some OS to run on this computer. Last time I looked through /etc/rc* on a SunOS 4.1.4 system, I noticed that nd support was still there, and thought that it was probably still possible to get it to act as a boot server, even for SunOS 3 for the Sun-2. I'm not real sure how you would install it with just the tapes and a tape drive on the newer system though, but then I can't remember how I got the 2/120 to boot the 2/50 either. -Frank McConnell

25 years, 5 months

ALTAIR stuff (was Re: E-Over Pay strikes again! original Altair disk sells for... )

by edick＠idcomm.com

What I find odd about the MITS FDD is that they used a 37-pin "D" connector and cable as opposed to the 50-pin more commonly seen on the 8" types. I found one among a set of enclosures I bought about 20 years ago. While this is already promised out (once I find the top of the box), I do know that there's an ALTAIR hard disk controller box, apparently with a drive inside, judging from the weight, at Gateway Electronics in Denver, (303) 458-5444, if anyone's interested. It's the same size as the ALTAIR FDD box. Dick ---------- > From: Allison J Parent <allisonp(a)world.std.com> > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: RE: E-Over Pay strikes again! original Altair disk sells for > Date: Friday, February 12, 1999 6:34 PM > > > <True enough I'm sure. MITS also produced a "mini"-floppy controller that > <was also a two board TTL set. The first board (computer interface) was th > <same board as in the 8" set (except for different RC values), the second > > Well heres where I stand on it. Never seen one, I was there, and never > seen an advert for one, I have back issues. Was it possible, sure. The 8" > design with some tweeks would certainly do minifloppy. > > Allison

25 years, 5 months

← Newer
1
...
37
38
39
40
41
42
43
...
71
Older →

Jump to page:

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 February 1999