Curt @ Atari Museum wrote: This reminds me -- what's a good 8-bit SCSI adapter for IBM PC 5150-class machines? I've got SCSI drives here that I'd like to put to use, but all I have for this machine is a Western Digital MFM controller. -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Want to help an ambitious games project? http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/

On 12/16/2005 at 1:01 AM Jim Leonard wrote: Don't overlook things like PC sound cards--some had SCSI adapters built on for CD drives. Old Bernoilli and scanner adapters are anohter sounce, assuming that you can find drivers for all of these--you need only get as far as ASPI support if you don't want to boot the drives. There are ASPI-interfaced general purpose drivers and utilities to go the rest of the way. A clue to finding drivers is to locate the SCSI LSI chip. The Trantor T130, for example, has an NCR 53C400. Cheers, Chuck

On 12/16/2005 at 12:23 PM Jim Leonard wrote: SCSI is pretty much SCSI if you've got ASPI support. I found a Corel LS-2000 driver on Driverguide that comes with ASPI drivers for DOS and Win95; I checked and it also has drivers for the aforementioned Trantor T130 also. http://members.driverguide.com/driver/detail.php?driverid=33593 Driverguide--and ask--if the people on this list are like me, I never throw a driver away. Cheers, Chuck

On 12/16/2005 at 1:49 PM Jim Leonard wrote: ASPI is easy--one of the good standards that came out of DOS--there's a Windows version of it also (16 and 32 bit). All you need is the correct ASPI device-specific driver in addition to the ASPI driver for your card. So, for a disk drive, it's going to be named something like ASPIDISK.SYS. Add this after the ASPI driver in your CONFIG.SYS and you're off and running--there may be other utilities included for managing an ASPI-driven SCSI disk drive. I haven't checked lately, but Adaptec included some fairly generic device-related drivers and utilities in their DOS driver kit (which was free for downloading). It's a layered approach. So, for example, to attach a SCSI hard drive to a PC using the Trantor/Adaptec T358 parallel port-to-SCSI "fat cable", my config sys would contain the following: DEVICE=MA358.SYS DEVICE=ASPIDISK.SYS There was a competitor to ASPI, called CAM, for Common Access Manager. It was similar to ASPI but somewhat more complex, some cards (Future Domain was one) used that in place of, or in addition to ASPI. Cheers, Chuck

On 12/16/2005 at 7:24 PM Jules Richardson wrote: There also was a PAS for 8-bit bus which included a Trantor SCSI adapter also. There are drivers for it on Driverguide. Chuck

On Fri, 16 Dec 2005 13:52:21 -0600 Jim Leonard <trixter at oldskool.org> wrote: Almost all 8-bit cards are increasingly rare with time. I go out of my way these days just to get ahold of ANY 8-bit ISA hardware at all, even 'common' cards are growing 'rare.' The PC and XT machines I got this past week are almost a 'fluke'- machines from the 'back room' of an industrial test lab. You don't find 8088-era hardware anywhere except in rare exceptions anymore. (and when I do, I almost always am the only person who wants it, and get it for virtually free, i.e. the complete PC Convertible I got several years ago at auction for a dollar, and the two Kaypro Portables at the same auction for a buck. And the wonderful Compaq Portable III I recently got)

t Most people think price follows value. For you/us to see an antique as valuable while simultaneously expecting others to price it as worthless trash is something of an exploitation for personal profit. Not necessarily unethical, but don't push it. Big rule of low(er) price negotiation. The more enthusiasm you show, the higher price you get. Another rule: asking more than 50% off is asking almost too much of anyone. Just say "This machine will not run any modern software at all -- no internet." John A.

On 12/17/05 9:25 AM, "John Allain" <allain at panix.com> wrote: That's the angle I tried, I mentioned that it wouldn't connect to the internet, and was shown a master price list that they weren't allowed to challenge. The cashier's had no negotiating power, and the manager would hear none of me, or anyone else, I think I asked once a week if it was still there and at what price, and for the three months I tried, it stayed there at it's same price tag of $50.

On 12/17/05 4:01 PM, "Lance Lyon" <lance.w.lyon at gmail.com> wrote: In this area, the shop assistants are more worried about getting shot or makng a drug deal then anything else, I guess they price for doped up idiots or something?

On Sun, 18 Dec 2005, Lance Lyon wrote: An XT can run Windows 3.00. It can't run 3.10 or newer.

Rumor has it that John Allain may have mentioned these words: Merch's Corollary: The farther away from home you are, the more costly your car parts are. "Don't let 'em see your Michigan license plates in Oregon." ;-) Depends on how unknowledgeable the people are of what they're selling. The last 2 CoCo2's I've seen at garage sales were marked at $70 and $75 each - bare, no carts, minimal cables. One wanted an extra $20 for the CCR-81[1] tape deck. We're talking 4, maybe 5 years ago, tops... Pentium 3's & Athlons were cheap & plentiful at the time. The first one I told the people that the machine w/tape deck was worth about $10, they thanked me for the info and asked me what I'd pay for it. I said $5. They were quite surprised, but when I told 'em I had 5 already (I was underestimating) I didn't need another one very badly. They sold it to me for $5. At the second place, I told them the same thing, they got all indignant, looked at me cross-eyed and said "Like you'd know." I told them "I do - I own several and I keep up with what they're worth." They then accused me of trying to undercut them - I told them "I own six now, I don't need another and I'm not buying yours no matter the price." They said "Would you take it for $1?" I refused & walked away. Many would not believe the sign. A lady bought a Ford dealership 68020 Unix server because it was in a big case. She asked me afterward: "It's bigger than my machine now, so it'll run Windows faster, right? ... And boy this sucker's heavy!" I calmly explained to her that it would not, and at first she wouldn't believe me, until she couldn't figure out where to plug in the PC monitor & keyboard. Laterz, Roger "Merch" Merchberger [1] The CCR-81 is notorious for being not very trustworthy with one's data. If you're looking for a Tandy data tape deck, search for the CCR-82 - *very* good deck. -- Roger "Merch" Merchberger | A new truth in advertising slogan SysAdmin, Iceberg Computers | for MicroSoft: "We're not the oxy... zmerch at 30below.com | ...in oxymoron!"

Tony Duell wrote: How do design glitches like that get past QA? (Or was there no QA?) One thing I love about my old IBM PC 5150 with ST-225 is that *it is still running 22 years later*. I fire it up at least once a week to do some hobby programing or game playing and the damn thing just runs. I can't say that for my modern machines -- I had an ATX power supply die on my twice in 5 years (had a 5 year warranty), and I've had modern drives fail quite spectacularly, etc., etc. but I've been spoiled by most of my old machines. They just work. I mention all the above because it was a surprise to hear that a piece of old consumer-level hardware had such a nasty flaw. Confused -- why would that fix it? -- Jim Leonard (trixter at oldskool.org) World's largest electronic gaming project: http://www.MobyGames.com/ A delicious slice of the demoscene: http://www.MindCandyDVD.com/ Various oldskool PC rants and ramblings: http://www.oldskool.org/

Tony Duell wrote: That made we wonder... what's the oldest *operational* digital machine owned by anyone on this list? Although I suppose it's hard to define 'machine' - something with RAM, I/O in some form, and at least one CPU (what the heck do you call a CPU when it's no longer central?) I remember the discussions a while back about age of list members, but I don't recall ever seeing a similar one about age of collections! Not having all the peripherals that would have perhaps originally gone with the machine is acceptable I think (I can see some people having room for a mainframe and control desk, but probably not for a bazillion tape / drum units to go with it!). But other than that, make it complete (i.e. things like the single rack of EDSAC that we have - whilst perhaps "operational" - doesn't count :) (I'd quite like to hear responses from people with analogue machines too, but someone else will be able to define qualifying rules much better than I can) Just out of curiosity! cheers Jules

Wai-Sun Chia wrote: Why not though? Assuming it's a faithful restoration using period parts [1] (rather than emulating bits using modern parts) and it works then it should qualify... I have no objections to museum machines being mentioned if the poster is directly connected with that museum [2] (nor would I mind hearing about ancient hardware that people are still using in a commercial capacity :) [1] Someone told me of one museum with an old machine where the core memory had been torn out and replaced with modern DRAM, but I can't recall what machine or where - to me though it's non-original at that point because it's not a restoration faithful to the original hardware. [2] I've mentioned our early 60's Marconi in a museum capacity. Oldest machine in my private collection is a lot newer - probably my Acorn System 1, circa 1979. I don't have room for big stuff, and the older a machine is the bigger it tends to be :-) I suppose I'm just curious as to what systems from the 1940's to 1970's have survived, as most of the talk on here seems to be of more recent (1970's and 1980's) hardware and very little gets said about the earlier stuff. cheers Jules

Chuck Guzis wrote: Hmmm, not sure. Quite possibly :) Reasonable age, though, considering how few machines prior to it are still (I expect) maintained in operational condition. Although see previous post - I wouldn't consider it original once a substantial element of the machine has been replaced with a modern part. Hopefully there's a plan to rebuild it in the longer term though, using bits seen some unbelievably small cores!). It even seems like one of those oddball projects that IBM would be up for sponsoring... Hopefully if it's also maintained in "running condition" there's a clear sign for the public that it's not completely original! cheers Jules

On 12/19/2005 at 12:46 PM William Donzelli wrote: At CDC, we used to joke about the "Tiajuana Core House"--at one time, bulk core (ECS) was being assembled there, IIRC. I remember an IBM CE poking around in a 7090 with a broomstick with a small magnet attached to the end to retrieve fractured bits of core after he'd given the unit a couple of good whacks to free them. Core can be very fragile stuff, particularly when it's being heated by repeated access. I recall that the CDC 7600 had some sort of duty-cycle integrator installed on PP memory because repeated hits on the same location would cause overheating and parity errors. Cheers, Chuck

Chuck Guzis wrote: I'd be very interested to hear that a 704 was still running somewhere! Paul Pierce has a 709 in his collection, but his website makes no claim that is running. At the time of the CHM 1620 restoration, the restoration team was in contact with a fellow who had a running 1620 that he had owned for some years. His machine was running with authentic IMB core. I have no idea if it still runs. --Bill

Oh, what about the people who have Kenbaks? Those are from 1971. -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Jules Richardson Sent: Monday, December 19, 2005 9:54 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Oldest machine Wai-Sun Chia wrote: Why not though? Assuming it's a faithful restoration using period parts [1] (rather than emulating bits using modern parts) and it works then it should qualify... I have no objections to museum machines being mentioned if the poster is directly connected with that museum [2] (nor would I mind hearing about ancient hardware that people are still using in a commercial capacity :) [1] Someone told me of one museum with an old machine where the core memory had been torn out and replaced with modern DRAM, but I can't recall what machine or where - to me though it's non-original at that point because it's not a restoration faithful to the original hardware. [2] I've mentioned our early 60's Marconi in a museum capacity. Oldest machine in my private collection is a lot newer - probably my Acorn System 1, circa 1979. I don't have room for big stuff, and the older a machine is the bigger it tends to be :-) I suppose I'm just curious as to what systems from the 1940's to 1970's have survived, as most of the talk on here seems to be of more recent (1970's and 1980's) hardware and very little gets said about the earlier stuff. cheers Jules

There is a fair amount of software available for your HP, contact me off list... ----- Original Message ----- From: "Brent Hilpert" <hilpert at cs.ubc.ca> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Monday, December 19, 2005 4:58 PM Subject: Re: Oldest machine

In article <43A698D0.1040301 at yahoo.co.uk>, Jules Richardson <julesrichardsonuk at yahoo.co.uk> writes: PDP-11/03, dual RL01s, LA-120, VT-100, 28 KW RAM running RT-11. -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>

I have a slide rule from the 1930s. :) Our local club, MARCH, has an HP 300A Harmonic Wave Analyzer. It's a got a four-digit serial number which begins with a "1". :) -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Zane H. Healy Sent: Monday, December 19, 2005 11:42 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Oldest machine (was: Re: Good haul of old pc stuph) I think the following would be my oldest complete systems, the big problem with the oldest DEC HW I have is getting some easy to interface with I/O, or getting the I/O I have up and running. The exception on this list would be the Apple II+. PDP-8/E PDP-8/M PDP-11/03 IMSAI-8080 Apple II+ Zane -- -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

In article <002501c604bc$8dbfae30$6401a8c0 at DESKTOP>, "'Computer Collector Newsletter'" <news at computercollector.com> writes: Lately I've been wondering if anyone attempts to collect mass-manufactured memorabilia by trying to get the lowest serial number. For instance, I have an Atari 800 serial #388801. Has anyone done a wiki/database type web page where everyone can enter the serial #s of their common computers? -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>

In article <Pine.SUN.4.20.0512192140490.7258-100000 at osfn.org>, William Donzelli <aw288 at osfn.org> writes: I'm not asserting that serial number #288801 would be "more valuable" than my serial number of 388801, but it can still be fun to try and get a lower serial number with mass-produced parts. As you say, there is no real correlation between the serial number and its provenance, but not everything in collecting has to do with provenance or market value.... -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>

My 1969 Imlac PDS-1 has a serial number of 2.

Ha, There are far more TRS-80's than Imlacs of any type, and most were "gr'Imlacs". I have an original 'alpha' imlac, without long vector support. Its a bit more rare than you think. ----- Original Message ----- From: "Jim Battle" <frustum at pacbell.net> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Monday, December 19, 2005 11:27 PM Subject: Re: Oldest serial number (was: Oldest machine

This is exactly where the system falls apart - when a manufacturer skips a block of numbers in a smaller run, it is not very obvious from looking at a small sample distribution. The military has played these games for years. During World War 2 there was a small U.S. intelligence office that would analyze the datatags of captured German and Japanese equipment, and they found that all sorts of info could be gleaned from them - production numbers, locations, subcontractors, etc.. They also realised that the Germans and Japanese could do the very same thing with captured US equipment! Thus, in 1942, there actually was a technical order sent out to deface the datatags on equipment. Military or corporate - the fear of spying is still around, and even little details can give too much away. And then there is the plain old simple reason for screwed up serial numbers - have you ever seen the quality of people that work in factories? How many can not actually even read? When in doubt (often), throw away that box of numbered stickers! William Donzelli aw288 at osfn.org

No, you will still miss lots of holes, simply because you just will not have a large enough sample. A database has helped with research like this (or for just plain fun, as mentioned before) - just the results should not be taken too seriously. There is a database of surviving DEC 36 bitters out there on the web. One problem is that often people with machines do not want it known, in some shape or form, and this throws ofdf the sample. I think that list has a few entries with deleted serials. I once did get a good sample for doing such a thing - they were radio control boxes for a 1930s bomber. I figure I had something like four or five percent of the entire production run, which is a very large sample. I found that there were big holes, some parts with nice even distributions, and even a repeat serial number. What I learned from this is that it is hard to learn anything from this. William Donzelli aw288 at osfn.org

Paul Allen's 2065B and 1090 are the newest additions to the PDP-10 serial number list. http://www.pdpplanet.org/ At 01:44 PM 12/20/2005, William Donzelli wrote: Michael Thompson E-Mail: M_Thompson at IDS.net

It sort of sounds like the harvest is over... William Donzelli aw288 at osfn.org

Michael Thompson wrote: While the CPU's are showing up, how about Disk and Tape drives? They're *one* of the reasons I've never looked into getting a real PDP-10, though space and power are about as important for me :^( BTW, have you ever figured out what tapes the museums collection has, that Tim doesn't have up on his site? Zane

On 12/22/05, Brad Parker <brad at heeltoe.com> wrote: An interesting thought, but weren't the RP disks formatted to 18-bit words when used on 36-bit hosts? If one kludged up an interface with some smarts, perhaps one could format a SCSI disk to something other than 512 8-bit-bytes per sector. The RP20(?) emulator could then request a larger block, then repackage it and feed it up to the KS10 as 36-bit words. How did Systems Concepts do it? I know they have differential SCSI interfaces and drives, but I have no clue about the internals? -ethan (who doesn't own any 36-bit hardware, but enjoys running TOPS-20 on klh10)

This is seriously cool! I can think of at least a couple people that will probably be interested, as the reliability of the drives are becoming a serious problem. Plus I think in a couple cases, there are people with KL10's, but no drives. If I had a machine that could use it, I know I'd be interested, but as it stands, I don't have a need for one :^( Zane

Ethan Dicks wrote: That's the idea. As I recall Eric Smith understood this - we emailed once and he mentioned supporting a 10 on unibus. I don't remember the details but I'm sure he know. (I'll dredge up the email) -brad always the difficult one, I've been enjoying ITS on klh10 :-)

The disks have to be for 36-bit systems, so not just any old drive of the models that were supported will work. I don't remember how much of this is a hardware, and how much of it is a formating difference. Zane

The RP06 that I use is very reliable. I rewired it for 220VAC single phase. Getting packs that work well is a different story. I think that the oxide is starting to come off on some of the packs that I have. After a few hours use it gets read/write errors and the heads get dirty. TU45 tape drives are a pain in the a. At 06:13 PM 12/22/2005, William Donzelli wrote: Michael Thompson E-Mail: M_Thompson at IDS.net

At 7:59 PM -0500 12/23/05, Tim Shoppa wrote: I could have sworn it was someone at RCS/RI, that said a couple years ago that they had stuff that wasn't in your your archive. It would definitely be nice to know what is there, am I remembering correctly that DEC/Compaq shipped them what remained of the DEC archives? Johnny thinks that there are tapes besides what he sent you, as we were discussing DECnet for TOPS-20, and he believes they should have a copy. BTW, have you found out if Paul Allen's systems include tapes you don't have? Zane -- -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | MONK::HEALYZH (DECnet) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

At 8:40 AM -0500 12/24/05, Tim Shoppa wrote: I'll have to see if I can figure that out... I know they dumped a *lot*, but I thought there had been some "official" dumping of what was left on CHM. And the trick is finding the 1% or so that might still exist and getting them imaged :^( Zane -- -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | MONK::HEALYZH (DECnet) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

All of the 1/2" tapes from RCS/RI are on Tim's site. We were talking last Saturday about putting an RL02 controller on the KL-10s 11/40 front end so we could copy all of the DecTapes to other media. That will be a project for next year. At 12:44 PM 12/22/2005, you wrote: Michael Thompson E-Mail: M_Thompson at IDS.net

While at one point I had three KS10s, I only have one now, and no, it will not "thaw". Unless one stokes the fire with some big IBM or Univac. William Donzelli aw288 at osfn.org

In article <Pine.SUN.4.20.0512201332350.7258-100000 at osfn.org>, William Donzelli <aw288 at osfn.org> writes: But was it fun? :-) If its fun, then its worth it. I like the simple "nya nya! my serial number is lower!" taunt among collectors of the same mass produced items :). -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>

Does anyone still collect UR equipment? A 407 is darned near a computer.

Scott Stevens wrote: Yep - I tend to try and leave those on if they're something interesting, even if I'm cleaning the rest of the machine up as much as possible. Partly to aid my own memory too, because I can never remember where I got half my stuff from! :-) On a related note, there's also something nice about finding signed documentation once owned by well-known staff at the company which produced that documentation. I suppose it's a similar thing - no big deal, but it just adds something somehow (to the historical value - I wouldn't have a clue whether it affects monetary value at all) cheers Jules

At 08:25 PM 12/20/05 +0000, you wrote: even to aid Oh, oh! I'm in trouble! MOST of my stuff has company stickers on it! Last week I was using a HP 9816 and I looked at it and the keyboard had a NASA property sticker, the disk drive had a Martin Marietta sticker and the CPU had a Harris sticker! Most companies have a policy that the property stickers are to be removed by the surplus department, but they leave it for the buyers to do and they leave it to theirs buyers, etc etc so most of the stuff hits the streets with the property stickers intact. Well it can be interesting to know the history of your machines but I agree that it's USUALLY secondary to their condition. OTOH a friend of mine has a couple of FLOWN computers from the Apollo spacecraft. In cases like that history is everything. Joe

In article <m1Eoo2v-000IyHC at p850ug1>, ard at p850ug1.demon.co.uk (Tony Duell) writes: Tsk tsk tsk. Don't you watch Antiques Roadshow on PBS? ;-). Its all about the provenance of a machine. -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>

It is interesting. Sometimes, with luck, with military electronics you can get unit or tail numbers off bits and pieces, or perhaps a previous life on a ship. I have traced some bits and pieces to Goddard Space Flight (most of their early digital phone system), the XB-52, battleships Texas, Idaho, and California, aircraft carrier Forrestal, and a DE called the Loeser. I also once had a VAX-11/730 with CDC tags - Horrors! William Donzelli aw288 at osfn.org

On 19/12/05 11:26, "Jules Richardson" <julesrichardsonuk at yahoo.co.uk> wrote: Hm. I've never powered it up but I've no reason (hah) to assume it doesn't work, my oldest digital machine is a Kim-1 from maybe 1976. Definitely working is a PET 2001-8, blue screen version which is what, 1978? Bung in the 1977 Atari VCS too..... Earliest analogue machine is my Magnavox Odyssey 1, 1972, if that can be counted as a 'machine' (on the flipside, the newest machine in the museum is a 2000-ish Mac G4 'sawtooth' :o) -- Adrian/Witchy Binary Dinosaurs creator/curator Www.binarydinosaurs.co.uk - the UK's biggest private home computer collection?

Jules Richardson wrote: I guess a straight 8 would be the most likely, but the PDP-1 and other machines may be accesed by list members if not owned.

I have an operation Heathkit EC-1 analog computer. Vacuum tubes and relays of course. Patrick Jules Richardson wrote:

On 12/20/05, Chuck Guzis <cclist at sydex.com> wrote: Absolutely! But still have to depends on whether your core is fully operational too.. Otherwise, you'd be classified as "degraded" and in need of restoration... :-)

1968 HP 2114 1969 HP2116 1969 Imlac PDS-1 ----- Original Message ----- From: "Jules Richardson" <julesrichardsonuk at yahoo.co.uk> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Monday, December 19, 2005 6:26 AM Subject: Oldest machine (was: Re: Good haul of old pc stuph)

On 12/20/2005 at 9:07 PM Jim Leonard wrote: ramdac has Ramdac? I The output of the CGA was plain RGBI digital, buffered through an LS244. There is a composite output, but it's sort of a simple-minded resistor adder network fet to the base of a 2n3904 to so some level shifting. Best recheck your RAM--and remember that writes to display memory on a CGA can occur only during the retrace interval or they produce "snow". Cheers, Chuck

On Tuesday 20 December 2005 11:45 pm, Jim Leonard wrote: Speaking of such, what are the RCA jacks (two of them) on those cards for? Is one of those supposed to be a composite output? -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

On Tue, 20 Dec 2005 21:03:46 -0800 (PST) Fred Cisin <cisin at xenosoft.com> wrote: That begs the question of what the two RCA jacks on the EGA card are for. I know that the one on the CGA card provides composite video.

On 12/21/2005 at 7:02 PM Jim Leonard wrote: AFAIK, on the original EGA, the answer is "they go to the expansion connector". No signals at all; NC, unless there's some sort of EGA expansion interface installed, such as a genlock board, in which case one is video in and the other is video out. On the IBM schematics, they're just labeled "EXT VIDEO" and "VIDEO". Cheers, Chuck

On Wed, 21 Dec 2005 21:22:46 -0500 Scott Stevens <chenmel at earthlink.net> wrote: To follow up, Tony answered some of these queries below in the thread. It's still an interesting question to ask what uses were made of the 'Feature Connector' on the EGA card, of course.

You can have composite video for any scan rates, although finding a monitor that works with it could be 'interesting'. However, The IBM EGA card (and I would assume the clones) can drive a CGA monitor at the standard (TV) rates. No, you don't get the higher resolution modes, but IIRC you can have more colours than on a CGA card. For that matter, the EGA card will also drive an MDA monitor at the MDA rates, and has a graphics mode that's not the same as hercules... But on an IBM EGA card (as I, and others, have pointed out), these connectors essentially go nowhere, just to pins on the feature connector. -tony

Clone CGA cards with no RCA sockets sometimes put the composite signal on pin 7 of the DE9 connector (this is a no-connect on the iBM card). Worth checking there anyway. -tony

Assuming yoy mean the 5155, it uses the Berg connector inside. 2 of the pins (ground and composite output) go to a twisted pair cable which goes to the monitor. The repaining pin on the Berg header is +12V IIRC. This is not used in the Portable PC (the monitor is connected directly to the PSU). I always assumed this was a handy power feed for an RF modulator should you want to use one with a CGA card. -tony

It is the same as the video Black sync used in TV studios to sync the cameras together. It allows multiple adaptors/monitors to operate using a single retrace timing reference.. This removes the rolling caused when televising a room full of computer monitors like you see on a news/weather set. There are some other user like video overlay that were seldom used. It can also be also used to allow mixing and switching between monitor outputs onto video tape or onto a split screen, without a time base corrector. Bob On Tue, 20 Dec 2005 23:53:56 -0500, Roy J. Tellason wrote:

12/20/2005 at 10:45 PM Jim Leonard wrote: That's what I was working from. Have you tried doing a read of the display every so often (without writing) and comparing to previous reads to see if bits are getting picked/dropped? That would settle the question of the RAM. I'm not sure if a read/write will find all problems. The CGA wasn't a bad design, considering what was available, although I wonder about using 74153's in U9/U10 rather than the LS or S parts. Now the MDA was a mess--traces going nowhere, logic that went nowhere. I've wondered if it was some incomplete design rushed to production. Cheers, Chuck

Do you have details on this resisternetwork ? i.e. is the CGA schematic online somewhere ? I need to add a composite output to a non-IBM CGA card and fit it inside a IBM5155 Jos Dreesen

The actual circuit is a bit more complicated than just a resistor network, because it also does NTSC colour encoding. But you wouldn't need that for the 5155. I've seen plenty of real IBM CGA cards on E-bay. Is there a good reason not to use one of those, and get the machine more original? I don't know of any CGA scheamtics on the web, alas. Anyway, shouldn't you be designing it yourself rather than taking somebody else's work? -tony

Jules Richardson wrote: And couldn't some 3COM TP/RJ45 combo 16-bit 'net cards do that too? I have a few, maybe I should just pop one in and try it... What's the worst that could happen? (famous last words) I will remember that and probably use later on in my tinerking, thanks. -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Want to help an ambitious games project? http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/

On 12/16/2005 at 7:44 PM Scott Stevens wrote: Well, an awful lot of the early CD-ROM drives were SCSI. I had a couple of NEC drives that resembled portable audio CD players more than anything--it's a separatel unit with a hinged top and a wall wart for power--and a SCSI interface. I also had a couple of the early CD-ROM drives that required you to purchase cartridges to put CD's in before inserting them into the drive--they were SCSI also. I don't believe that the early IDE CD-ROM drives were ATAPI, either, so SCSI was the closest thing to anything standard. My first sound card certainly had a SCSI adapter on it. Cheers, Chuck

Quoting Jim Leonard <trixter at oldskool.org>: Future Domain 8xx series. Some are bootable, some are not .. do a wee bit of research first. Some also have non-standard connectors on the back, so they should be avoided. These are known to work on a PCjr with an ISA bus adapter. (Software only - I've not fixed the ROM extension to give it native BIOS support on the Jr.)