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101090 discussions

Graphics for S-100 machines (MicroAngelo S-100 Graphics BoardbySCION)

by ajp166＠bellatlantic.net

> >Subject: Re: Graphics for S-100 machines (MicroAngelo S-100 Graphics BoardbySCION) > From: Richard <legalize at xmission.com> > Date: Mon, 03 Dec 2007 17:33:08 -0700 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > > >In article <475499E1.9030304 at pacbell.net>, > Jim Battle <frustum at pacbell.net> writes: > >> There were other graphics cards on S-100 too. I've seen (recently) an >> S-100 card that had one of the TI bitmap & sprite generator ICs on it. > >Maybe it would be a fun "extend my S-100 machine" project to add a >simple graphics frame buffer? You could put a frame buffer on the >card, expose a window of the frame buffer via memory mapped I/O on teh >bus and a simple VGA output controller in an FPGA. I don't know what >you'd do with it after that, since it would be so non-standard that >there isn't any "off the shelf" software you could use with it, but it >might be a nice retro-fit! A good fit is the NEC7220, used in the Rainbow. It was one of the first graphics controllers to bridge the CRTC and the graphics world as known now. If you can find one that is a good candidate for S100 for a 3 or 4plane color system. Allison >-- >"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download > <http://www.xmission.com/~legalize/book/download/index.html> > > Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 4 months

Mechanical calculators

by Arno_1983＠gmx.de

M H Stein <dm561 at torfree.net> wrote: > From: "Arno Kletzander" <Arno_1983 at gmx.de> > > >My contribution however was not targeted at the IBM equipment thread, > >btw. > ------ > MHS: > > I realized that, which is why I left the original subject line. (...) > the second part of my reply dealt with the type you're talking about. Sorry for the misunderstand, thanks for clearing up. > >Yes, exactly that is the class of machines I meant. There were similar > >ones which printed on a platten carriage mounted behind the adding > >machine body (...) > ------ > MHS: > > And those were the "posting" or "accounting" machines I was talking > about; in the Burroughs line that I worked with, the electro-mechanical > ones equivalent to the IBM punch card equipment we've been discussing > were the "Sensimatic" F series, programmed by a removable program panel > with two sets of "pins," (...) > I had three of these at one time, but scrapped them all long ago. > > The later electronic versions were the "E" series; a good brochure with > pictures of a type of computer largely ignored in the various histories > (although there's a brief mention in The Encyclopedia of Microcomputers), > with core memory and magnetic stripe & PPT/EPC I/O (...) > > Incidentally, Sensimatic referred to the way the program pins > were "sensed;" the pins were different lengths which determined the > operation to be performed (add/subtract/print/etc.) and different pin > locations determined the register number or the accumulator (sound > familiar?). A set of sensing pins would rise up to measure the length of > the program pins, and the keyboard also had "function keys" (called > OCKs - Operator Control Keys) for different options (normal entry, error > correction, etc.) > > A program would consist of steps like "Load A (from keyboard) (INP 01), > "LD R1, 2 and 3 from A," "SUB A from R5&6," "Punch A (OUT 2)," "IF OCK3 > then SKIP (JMP) to Step12," etc., all done mechanically with gears, > levers and springs of course. Programming was done with a nibbling tool, > a tray of numbered different length pins and a screwdriver. > > Wouldn't you love to have 20 registers today, and the ability to > load/store more than one simultaneously? Mind you, that was also the > entire memory until electronic versions came along... Uhh, what have I done to deserve this treatment? You make me long for those big ugly heavy boat-anchors even more than before. Must...go...chastise myself (before my parents do when I bring home the next one :-)) All joking aside, my collection in the field of accounting machinery is pretty fragmentary yet: All I have is a Triumph Duplex wide carriage accounting typewriter (Wahl actuator principle, supposedly pre-WWII) with motorised carriage return and just two registers (one on the carriage for vertical sums, one on the machine body for horizontal sums, and an empty shell that activates the horizontal register but doesn't accumulate in itself - there sure must have been more), and a Triumph-Adler "TA 20 compact" electronic facturing typewriter which pretty much looks like a Selectric with a numeric keypad, a few extra lamps and all dressed in white. The older one was a dumpster find and is unrestored as of yet - there's a load of rust, dirt und grease gunk inside and I'm not so sure if I'm going to get it reassembled if I take it to pieces far enough to clean it out. The electronic machine was a present from my grandfather who was a office machinery serviceman, it was my practice machine for the touch-typing course I took in grammar school and it's working to this day. There is a keyswitch to select either typewriter or facturing machine mode, the customer-specific facturing program (for which I was lucky enough to also get some documentation; obviously the machine was used in a carpetry store) is hard coded in an EPROM and even contains the postal adresses of some regular customers. Writing a new program involved some precoding on forms. Then, a cassette-based "programming accessory" was attached to the machine, the program entered and saved to tape. The programmer (and the customer?) could test it for correctness; if it was accepted, the tape was sent to the factory, the program burned to EPROMs and these sent back to the serviceman for installation. Unfortunately, I do not have that accessory, and working out the interface for building a replacement is somewhere quite low on my priority list. Oh, I forgot that "GROSS U.K." restaurant cash register with key-locks for eight waiters and dual printer for receipt and journal. This one is also working, but the case has a few dents in it. But something I'd really consider a find is one of those desk-sized facturing machines, say a Rheinmetall FME series - this has a motorized mechanical four-species calculator in the desk drawer which is electrically linked to the typewriter on top: magnets for input, contacts for readout. My grandfather detested those, as they used 120V DC to pick the magnets and there were lots of unencapsulated contacts within the mechanism... Greetings, -- Arno Kletzander Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! Ideal f?r Modem und ISDN: http://www.gmx.net/de/go/smartsurfer

18 years, 4 months

Micro Five system

by doc＠mdrconsult.com

I ran across a "Micro Five" motherboard this morning. The gent who owns it (just the system board, not a whole system) tells me that it was an 80286-based system built to run Netware. It has 2MB of RAM onboard, and several slots for 8MB memory cards, and Ed says that the disk subsystem lived in an external unit. The thing is huge - roughly 20" by 28". I found only one google hit on it, and that was a post asking for info. I'm not even sure why I'm interested - he's not going to give it up - but I am curious about it. I'm especially curious about the memory. If his recollection of the memory options is right, this thing supports 34MB or so. How is that possible on a 286? Doc

18 years, 4 months

Early Intel 55S073 IC, RAM Chip?

by marvin＠west.net

I found a site that has a lot of chip logos: http://www.elnec.com/support/ic-logos/?method=logo Looks like the 55S073 is an Intersil chip, and not Intel. But I still haven't been able to find out any information on this chip.

18 years, 4 months

Early Intel 55S073 IC, RAM Chip?

by marvin＠west.net

/rant on Will, I am *VERY* critical of Ebay and generally view them as operationally inept or challenged, and I would much rather see VCM succeed as an alternative. I don't like dealing with organizations I view as unethical. /rant off I didn't have time to put up a picture of the chip, so I just uploaded one to: http://www.west.net/~marvin/55s073-1.jpg In looking at it again, this doesn't look like an Intel logo, so I am curious who did make this chip. I thought it might be intersil, but so far, I haven't seen any Intersil logos that look like this one. > > I am starting to list some chips and "stuff" on Ebay (hanging my head), but the > > mortgage company would really like me to continue paying them, and Ebay > > unfortunately is the best venue for some of this stuff :(. > > There is no shame in this. > > -- > Will

18 years, 4 months

Graphics for S-100 machines (MicroAngelo S-100 Graphics Board by SCION)

by legalize＠xmission.com

One of these just sold on ebay item # 290186096576 I was looking at it because its graphics (I have no S-100 machines), but even had I remembered to bid on it I would have been priced out :-). Are graphics boards for S-100 machines common at all? It seems not. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 4 months

Early Intel 55S073 IC, RAM Chip?

by marvin＠west.net

I am starting to list some chips and "stuff" on Ebay (hanging my head), but the mortgage company would really like me to continue paying them, and Ebay unfortunately is the best venue for some of this stuff :(. I ran across this chip in my collection and only found one Google reference. It appears to be an early (code date 7238S) Intel 256 Byte RAM chip. Is this actually one of those *RARE* type chips?

18 years, 4 months

Graphics for S-100 machines (MicroAngelo S-100 Graphics Board bySCION)

by ajp166＠bellatlantic.net

> >Subject: Graphics for S-100 machines (MicroAngelo S-100 Graphics Board bySCION) > From: Richard <legalize at xmission.com> > Date: Mon, 03 Dec 2007 16:14:57 -0700 > To: cctalk at classiccmp.org > >One of these just sold on ebay item # 290186096576 > >I was looking at it because its graphics (I have no S-100 machines), >but even had I remembered to bid on it I would have been priced out >:-). > >Are graphics boards for S-100 machines common at all? It seems not. Generally no. They existed and were available but the requirement was not there (killer app that used it). That however changed near end of life for S100 as there were CPUs 8088/86, 286 and concurrent CP/M and even MS-DOS sop grpahics support and use was desireable. However MicroAngelo, Comemco dazzler and others were out there in the wild. Generally though when I've seen them they were in embedded S100 systems being used for process controls (dairy, and other production factilities). Seems that market liked graphics and used it. Allison

18 years, 4 months

Mechanical calculators (was: Re: *updating* 8088's)

by dm561＠torfree.net

-------Original Message: Date: Sun, 02 Dec 2007 23:06:02 -0800 From: "Chuck Guzis" <cclist at sydex.com> Subject: Re: Mechanical calculators (was: Re: *updating* 8088's) On 3 Dec 2007 at 1:46, M H Stein wrote: >> (Chuck: change the colour, remove the cabinet on the left and put it on tubular legs >> and you've got the picture you're looking for - remove the alpha keyboard for one >> of the older numeric-only models ;-) >How about the National Class 3000 from 1929? One can be seen on the >page numbered 140 in this very interesting document from Portugal: >http://www3.dsi.uminho.pt/memtsi/docs/guia_exposicao_ilustrado.pdf >Cheers, >Chuck ----- Well, the Burroughs F styling was a _little_ more modern and the Sensimatic program panels were a Burroughs trademark, but yes, that's the idea (even the flip-up table for the ledger tray on the left). The one in the eBay ad that Arno mentioned is a fairly late model F with the beige and blue colour scheme; the older ones were dark brown. Some nice pictures on that Portuguese site; even the 517 interpreter that got that other thread going. Incidentally, Sensimatic referred to the way the program pins were "sensed;" the pins were different lengths which determined the operation to be performed (add/subtract/print/etc.) and different pin locations determined the register number or the accumulator (sound familiar?). A set of sensing pins would rise up to measure the length of the program pins, and the keyboard also had "function keys" (called OCKs - Operator Control Keys) for different options (normal entry, error correction, etc.) A program would consist of steps like "Load A (from keyboard) (INP 01), "LD R1, 2 and 3 from A," "SUB A from R5&6," "Punch A (OUT 2)," "IF OCK3 then SKIP (JMP) to Step12," etc., all done mechanically with gears, levers and springs of course. Programming was done with a nibbling tool, a tray of numbered different length pins and a screwdriver. Wouldn't you love to have 20 registers today, and the ability to load/store more than one simultaneously? Mind you, that was also the entire memory until electronic versions came along... And of course they usually had colour printers ;-) (Red & black ribbons). BTW, AFAIK some Teletypes used the same type "box" as the typing Sensimatic that Arno is talking about. Think I still have one of those somewhere as well. m

18 years, 4 months

cctalk Digest, Unwanted / Available parts

by mike＠brickfieldspark.org

Added a search facility on http://www.soemtron.org/partsavailable/index.html and updated Mikes sample page with more representative list of parts. Updated home page with expanded description an aims. Since release last Friday have had one live enquiry. Mike.

18 years, 4 months

Mechanical calculators

by Arno_1983＠gmx.de

"Chuck Guzis" <cclist at sydex.com> wrote: > On 2 Dec 2007 at 19:18, Arno Kletzander wrote: > > > Yes, exactly that is the class of machines I meant. There were similar > > ones which printed on a platten carriage mounted behind the adding > > machine body, and some of the latest electromechanical models had a > > "type box" as a means of commenting the ledgers, invoices - whatever. > > Could you perhaps point me at a web photo of such a machine? Heh...you just sent me on a journey through some of my hellboxen since I didn't remember the name of that particular machine and I had to dig out the book where it's in (Buchungsmaschinen, GMD Report No. 162, by Werner Lange). It has lots of pictures and drawings about both adding machines and bookkeeping/facturing typewriters (Wahl actuator, Burroughs-Moon-Hopkins,...) However it looks like I mixed up some stuff: The typebox printing element depicted in the book is described as belonging to a Burroughs Typing Sensimatic - an advertisement can be seen under ebay auction number 260181621699, but this shows a typewriter keyboard in front of the adding machine part. The keyboard with dual legends depicted in the book however (which I wrongly associated with the typebox) belongs to a German Zeiss-Ikon adder from 1958, no further classification given. The printing mechanism of this machine is described to consist of three disks or typewheels able to print a set of 42 characters. Greetings, -- Arno Kletzander Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten Browser-Versionen downloaden: http://www.gmx.net/de/go/browser

18 years, 4 months

Unwanted / Available parts - update

by mike＠brickfieldspark.org

Well I've already had a bite for some bits of the "Mike" page, so there may be some mileage in this idea yet. www.soemtron.org/partsavailable/index.html Mike.

18 years, 4 months

Bought a 4GB USB stick today, and guess what...

by ajp166＠bellatlantic.net

> >Subject: Re: Bought a 4GB USB stick today, and guess what... > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Sat, 01 Dec 2007 21:58:19 +0000 (GMT) > To: cctalk at classiccmp.org > >> >And of course a 4040 from Intel is a 4-bit microprocessor, from RCA it's >> >a 12 bit CMOS counter. I can never rememebr what the 4004 is in the >> >4000-eries CMOS, it's sufficiently rare that none of the data books I >> >have to hand list it. >> >> >> ur kiddin. Just prefix 74{c, hc, hct} and the 4xxx number and you >> get it's function and pinout. > >None of my data books list a 74HC4004 either. Does it even exist? I have data but in 1973 it was already replaced by 4024 a 7 stage binary counter. > >The 74HC4040 exists, and as expected it's a 12 bit ripple counter. That and the 4060 (14stge counter) are still widely used. >> However for us who kept those old and valuable manuals like Signetics >> 8xxx series and the RCA databook series (my 1973 set was some 8 books) >> I do have data for RCA 4xxx and a lot of other oddities. > >I haev never thrown out a databook. Darn it, I've got an Ericson databook >for Dekatrons and Trochotroncs, etc. And a valve databook from the 1940s >that has printed on almost every page 'Supply of this device cannot be >guaranteed due to the current situatio' (that is, of course, WW2). ;) That and my RCA powe tube manuals from the 50s, 60s and even a 1970 copy. Whats scary is that I have old databooks to support the old parts I HAVE and use. Allison >-tony

18 years, 4 months

Mechanical calculators (was: Re: *updating* 8088's)

by dm561＠torfree.net

Date: Sun, 02 Dec 2007 19:18:11 +0100 From: "Arno Kletzander" <Arno_1983 at gmx.de> Subject: Mechanical calculators (was: Re: *updating* 8088's) M H Stein <dm561 at torfree.net> wrote: >> The IBM unit record or Tabulating machines that we've been discussing >> had their roots in the same principles as these calculators, adding >> machines and cash registers (...) >Thanks for that interesting piece of history! Nice insight into the workings of >unit record equipment, a quite fascinating category of data processing in itself. >My contribution however was not targeted at the IBM equipment thread, btw. ------- MHS: I realized that, which is why I left the original subject line. I just thought it was a relevant and interesting link to the other thread about IBM punch card equipment which was very similar in function but replaced manual entry with punched cards; the second part of my reply dealt with the type you're talking about. ------ "Chuck Guzis" <cclist at sydex.com> wrote: > "Roy J. Tellason" <rtellason at verizon.net> wrote: > > This stirs a vague recollection of an old mechanical adding machine I > > once had, the kind that had a big rectangular array of buttons instead > > of just a "10-key" set of numbers. I have *no* idea how it stored a > > number in there, though. > > (...) > > When you mention the big array of keys, I think of a comptometer. > There's a nice discussion on the web: > > http://www2.cruzio.com/~vagabond/ComptHome.html > > But the item I'm thinking of was alphanumeric, more like a Teletype. > > Cheers, > Chuck Yes, exactly that is the class of machines I meant. There were similar ones which printed on a platten carriage mounted behind the adding machine body, and some of the latest electromechanical models had a "type box" as a means of commenting the ledgers, invoices - whatever. The letters were assigned as secondary functions to some of the keys and the machine would print those instead of accepting numeric input when it was in a column definded for comments (which was done by sticking pegs into a programming board moving together with the carriage). -- Arno Kletzander ------ MHS: And those were the "posting" or "accounting" machines I was talking about; in the Burroughs line that I worked with, the electro-mechanical ones equivalent to the IBM punch card equipment we've been discussing were the "Sensimatic" F series, programmed by a removable program panel with two sets of "pins," one that determined the actual operation to be performed and sort of equivalent to the IBM patchboards, and another to control carriage movement (sort of equivalent to the forms control tapes of an IBM 40x). The panels had a selector knob which rotated the tab stops to four different sets of positions and shifted 4 sets of program pins sideways slightly, so that one panel served for four "programs" and of course you could have as many panels as you needed. Incidentally, Fs could optionally also punch PPT & cards. I had three of these at one time, but scrapped them all long ago. The later electronic versions were the "E" series; a good brochure with pictures of a type of computer largely ignored in the various histories (although there's a brief mention in The Encyclopedia of Microcomputers), with core memory and magnetic stripe & PPT/EPC I/O, can be found here: http://archive.computerhistory.org/resources/text/Burroughs/Burroughs.E1400… (Chuck: change the colour, remove the cabinet on the left and put it on tubular legs and you've got the picture you're looking for - remove the alpha keyboard for one of the older numeric-only models ;-) This is a fairly small one with the electronics in the desk itself (although you can see the thick cable connecting the console to the processor), and it is still programmed with the same type of program panel; the cabinet on the right is a 4003 auto-reader for magnetic stripe cards, usually master file records whose data was usually merged/combined with the data on the mag stripes of the transaction cards feeding through the carriage. Larger models (E2000 etc.) had a separate electronics cabinet the size of a large freezer. Come to think of it, I still have the desk from an E1200 I scrapped long ago which is presently supporting a Cromemco System 3, and also still have one of the tape perforators you can see on the right side of the E1200 in that brochure, as well as a few other odd parts... The "E" series was later replaced by the "L" series which finally abandoned the full keyboard and used "normal" machine language programs loaded from PPT or ledger cards (and, later, cassettes). That was the machine, incidentally, which got me out of being an "employee" and took me into self-employed programming, consulting and support, which is what I've been doing for the last thirty-odd years, so I have fond memories of it... The last Burroughs machines of this class were the B80 & B90 which used disks and represented the transition to more conventional computers, with optional displays and terminals, datacomm etc. m

18 years, 4 months

VAX 11/750 power supply fault

by dkelvey＠hotmail.com

> From: ard at p850ug1.demon.co.uk >> > You might be confusing this issue with another one. That is, the power > supply control circuitry needs to be powered. Once the supply is > running, it; can be powered from one of the outputs of said supply, but > at swich-on, the power supply outputs are all 0, to the power control > circuitry is not powered, so the supply can't do anything, so the outputs > remain at 0. > Hi Tony No, I'm not confused. If the feedback circuit isn't running, there is no feedback. The feedback is such that it is positive at the interface between the low and high side. This way a failure in the feedback would bring the supply output to zero. To Make this work, there needs to be some way of getting things started. There is a oneshot on the high side that gives the supply a single kick on powering on. This also gets enough voltage to start the overall feedback that is negative from the output to the high side. It is just enough to blink some LEDs. A clever circuit but hard to trouble shoot. The first kick is so short, it is hard to catch on a meter and distinguish between lack of feedback and the over voltage protection( which also kills the feedback at the interface ). I spent time analyzing the overvoltage parts before realizing that it was a complete lack of feedback that was the problem and not the over voltage protection. The problem traced to an open ( poor solder ) inside the pulse transformer that connected the low side to the high side and provided the pulse width modulation for the supply. I'd call it a tricky circuit because as you seem to consider, it goes against common sense in that no feedback is no output. No feedback just means no pulse modulation and hence no output. As I also stated, the DEC supply most likely used a second powersource for the regulation feedback. Dwight _________________________________________________________________ You keep typing, we keep giving. Download Messenger and join the i?m Initiative now. http://im.live.com/messenger/im/home/?source=TAGLM

18 years, 4 months

Nice PDP8 gear available in Sweden

by wmaddox＠pacbell.net

A fellow in Sweden is offering some very nice PDP8 gear, including a loaded PDP-8/E chassis, an RK05, and some additional peripherals. For you folks on the other side of the pond, here's your chance. He's eBay savvy, however, so expect to have to make a serious offer. You can find more info at his website: http://www.neab.net/pdp-8e/ Of particular interest is an extremely rare MR873a Microprocessor ROM Programmer, which appears to interface to the PDP8. I have no connection with the seller other than as the buyer for a few of his eBay auctions. --Bill

18 years, 4 months

Mechanical calculators (was: Re: *updating* 8088's)

by Arno_1983＠gmx.de

M H Stein <dm561 at torfree.net> wrote: > The IBM unit record or Tabulating machines that we've been discussing > had their roots in the same principles as these calculators, adding > machines and cash registers (...) Thanks for that interesting piece of history! Nice insight into the workings of unit record equipment, a quite fascinating category of data processing in itself. My contribution however was not targeted at the IBM equipment thread, btw. "Chuck Guzis" <cclist at sydex.com> wrote: > "Roy J. Tellason" <rtellason at verizon.net> wrote: > > This stirs a vague recollection of an old mechanical adding machine I > > once had, the kind that had a big rectangular array of buttons instead > > of just a "10-key" set of numbers. I have *no* idea how it stored a > > number in there, though. > > (...) > > When you mention the big array of keys, I think of a comptometer. > There's a nice discussion on the web: > > http://www2.cruzio.com/~vagabond/ComptHome.html > > But the item I'm thinking of was alphanumeric, more like a Teletype. > > Cheers, > Chuck Yes, exactly that is the class of machines I meant. There were similar ones which printed on a platten carriage mounted behind the adding machine body, and some of the latest electromechanical models had a "type box" as a means of commenting the ledgers, invoices - whatever. The letters were assigned as secondary functions to some of the keys and the machine would print those instead of accepting numeric input when it was in a column definded for comments (which was done by sticking pegs into a programming board moving together with the carriage). -- Arno Kletzander GMX FreeMail: 1 GB Postfach, 5 E-Mail-Adressen, 10 Free SMS. Alle Infos und kostenlose Anmeldung: http://www.gmx.net/de/go/freemail

18 years, 4 months

VAX 11/750 power supply fault

by oldcpu2＠rogerwilco.org

Quoting Clint: > I have a "spare" 11/750 supply that I can loan you. Since it is out of a > machine, I'd need to get it back eventually. If you can troubleshoot it > down to a single board I can loan that as well (to save on shipping) > I'd also suggest you measure the resistance between +/-15V and ground on > the backplane without any cards plugged in. A bad capacitor or shorted > pin could make the supply current limit trip as well. Let me do some further testing, maybe under Tony's guidance, and we'll see what happens. This could be a good fallback if needed. Thanks for the offer. Let's leave this on the table for now. - Jared

18 years, 4 months

RM02 Massbus adapter troubleshooting

by pat＠computer-refuge.org

I'm trying to get a few RM02 drives going, which I picked up about a month ago. I can't get the RH11 I've got to talk to the MBA (Massbus adapter) in the drive (it reports a 'timeout'), and I think I've traced down the fault to a problem with the massbus transceiver, but wouldn't mind someone else taking a look at this... On page 2 of the M5922 schematics, signal AA2 DEMAND A H is generated >from a 75108. It looks like the signals "IF5 PORT A ON H" and the global enable from the switch on the board are both high and "MASS FAIL H" is low (and thus "AA2 MASS FAIL A L" is high). When the controller toggles the DEM(and) line on the massbus, I see "MASS DEM A H" and "MASS DEM A L" at pins BV2 and BV1, respectively, change state, but the output "AA2 DEMAND A H" stays low. Any ideas? I guess that either the 7417 at E3 could be defective, or the 75108 at E17 could be to blame. Or, is there something else that I'm missing? BTW, after staring at the MASS FAIL logic for a while, I looked up a datasheet for a 7417, and realized that it's just a buffer, and not an inverter (as it's drawn in the print set). Pat -- Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

18 years, 4 months

IBM 5161 Extender Card DIP Switch Settings

by bear＠typewritten.org

Does anybody have information how to set the memory size correctly with the 4-pos DIP switch used on the IBM 5161 Extender Card? Thanks. ok bear

18 years, 4 months

Bought a 4GB USB stick today, and guess what...

by jos.mar＠bluewin.ch

.. the ( single) flash chip in it is a "HY27UV08" Either someone at Hynix has a sense of humour, or they have run right out of IC codes and have come full circle to 2708 again. Jos

18 years, 4 months

Amiga 1000

by chrism3667＠yahoo.com

does anyone operate one of these? That is does anyone favor this machine over any of the later models? Commercially ISTR it being a flop, so that might seem like a strange question, but there is no lack of strange birds on this list. If you know what I mean LOL LOL! Hey maybe I'm stranger then the rest of you birds LOL LOL LOL! anyhow interested in the thoughts that find this unit particularly enjoyable. ____________________________________________________________________________________ Be a better sports nut! Let your teams follow you with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ

18 years, 4 months

For trade: SGI Iris 4D/310VGX

by silent700＠gmail.com

It's time to clear some space and say goodbye to an unfinished project. my SGI Iris 4D/310VGX. She's a double-wide deskside cabinet, I believe with an R3000 33mhz CPU. The power supply is dead, having traded her good PSU to revive a somewhat more alluring SGI Crimson. There are no hard drives or hard drive sleds. There is a CPU card, RAM card and video card. The external plastics are in pretty good shape; some scratches here and there. The clasp on the front door might be cracked, but the hinges are good and it stays closed with tape. A fine project for revival or as a parts machine for another SGI. I really don't want to part it out myself; I'd like the whole machine gone. So that probably means local pick-up only, since it's a back-breaker. I'm in Palatine, IL, northwest of Chicago. I'd like to trade for.....well pretty much anything smaller than the Iris. Any token cool item is fine. If no one has anything for trade, I'm sure I'll end up giving it away. -j -- silent700.blogspot.com Retrocomputing and collecting in the Chicago area: http://chiclassiccomp.org

18 years, 4 months

AMSTRAD PCW8256 systems & sw available

by speedracer005＠mac.com

My dad is 82, a retired College Professor, he owns a Amstrad PCW 8256 and his printer is broken. The printer head doesn't seem to go anywhere so it can't print. Is there someone in the USA that you know of that can help me, we are in California. If you do not know of anyone in the USA is there a way you can direct me to someone I can buy parts from that speaks english or at least can communicate through email in english. thank you, Steve Martin

18 years, 4 months

How easy is it to damage an IBM CGA display?

by mbbrutman-cctalk＠brutman.com

I'm having a bad day here .. I mistook an IBM Industrial CGA display for a monochrome display, and plugged it into a monochrome display adapter port. There was no smoke or funny noises, but it definitely did not work. I've heard stories about the IBM monochrome displays being fragile when mishandled like this. Were the IBM CGA displays also this fragile? (I won't be able to test it until I dig out a CGA card. And now of course I'm just paranoid and hoping that I didn't hurt it.) Mike

18 years, 4 months

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