test-drb March 1999

test-drb@ccmp.vtda.org

191 participants
1003 discussions

"new" classics (was Re: Pre-history of Digital Research)

by allisonp＠world.std.com

<>Simm sockets, PLCC and other chip sockets and the z280s were socketed to <>start with. < <Cool... Can I have a copy of your assembly documentation? Why, It's going to be a single copy wirewrap. The bulk of the docs will be a print set to work from, maybe a wire list and software. Allison

25 years, 3 months

Rebirth of IMSAI

by dogas＠leading.net

Why not create a current design for a modern front panel system? ok, retro styling because I like the silk screening of the 8800b and the 8080 but with *some* modern accoutrements while still providing that front panel experience. - Mike: dogas(a)leading.net

25 years, 3 months

Fw: Pre-history of Digital Research

by edick＠idcomm.com

I've got to disagree on this one. From what I've observed the 100-pin card-edge connectors are pretty common. I really don't know why, but they are. Every time I look at the local surplus parts house, I see those old connectors, in the same box they were in 20 years ago, even though the store has moved 3 times, with the label "S-100 Connectors, $3.95." They sit right next to a box of connectors nearly the same size, which says on it, "Multibus Connectors, $4.95." They seldom have the 30-pair connectors used on the secondary connector for Multibus-I, nor do they often have the 31-pair or 18-pair connectors used on a PC backplane. Now, I didn't say I like the price, but there they are. I don't know of many parts which were used in these old products, with the notable exception of the UART (TMS 6011, AY5-1013, etc) which were popular back in the mid-1970's. They were mostly standard TTL, though, which, if replaced with the currently popular CMOS equivalent may suffer from the poor designs of yesteryear. Back then we were still learning about race conditions and setup and hold time violations, and the like. Back then, a circuit designed to operate from a 25 MHz clock was taxing the limits of the technology, while today, people don't even blink when the clocks are over 10 times that fast. Replacing the old "standard" TTL with the still-available LSTTL may prove hazardous because of timing changes as well, and some of the old tricks with capacitors as delay elements may not work properly either. There are plenty of problems. Getting the common TTL of that era won't be as easy as it was then, but it won't be a lot more difficult. Now that I know this rebirth is a possibility, I won't throw away any more of the old standard TTL or small memories, though. Dick -----Original Message----- From: Allison J Parent <allisonp(a)world.std.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, March 20, 1999 11:50 AM Subject: Re: Fw: Pre-history of Digital Research ><An important thing to remember is that the Original IMSAI sold for almost ><$1000. So even though a new Pentium II 400 is only $1000 with all the bell ><and whistles there is a cost savings due to selling hundres of thousands o ><the thing. An IMSAI kit maybe a few hundred or so.< > >Doing an Imsai would be expsnsive as finding the parts would be costly. >Many arent made or are such low volume (100pin connector for sure) that >it isn't going to be cheap. > >For example the backplane 18 slots (or was it 22) roughly 13"x18" two sided >in quantities of 100, I'd bet that would be a $100 right there. Even in the >S100 heyday $49 was cheap (no connectors or anything else). > >Allison >

25 years, 3 months

H11 vs H11A ?

by mbg＠world.std.com

>What does the "LTC" switch do on an H11A ? Which is more common? (H11 or >H11A) Can an H11 be "upgraded" to an H11A? If it is anything like the LTC switch on a BA11-M or BA11-N, it enables or disables the Line Time Clock... I can't answer about H11 v. H11A Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+

25 years, 3 months

Seller's market

by Watzman＠ibm.net

The messages by some of the participants shows that they really do not understand [or perhaps do not want] the concept of a free market. What they really want is a highly imperfect market so that they can buy things at low prices even though there are people around who are willing to pay more [given the presumption that all sellers will sell to the highest bidder ..... and I use the term bidder loosely, not necessarily to imply an auction type format]. The internet is having a huge impact on buying and selling because it is creating the most free and perfect market that ever existed. The definition of such a market is that every buyer knows of every seller, and vice versa; the sellers are able to find the buyer willing to pay the highest price, AND the buyers are able to find the sellers willing to sell for the lowest price. GROW UP ! You have no right to complain because someone else is willing to pay more than either you are willing to pay or than you think that the item is worth. In the latter case, someone else obviously disagrees with you, and IS willing to put their money where their mouth is. That said, I do feel that steps should be taken to INSURE that bidders complete their deals. If I were a seller, and someone bid $5,000 and then backed out, I'd seriously consider legal action to enforce specific performance. I believe that bids on E-Bay are legally enforceable, but in 90% of the cases, because of both the amount and the fact that the buyer and seller are probably in different states, it is just not practical to try and enforce it. However when the bids get into the thousands of dollars, the situation changes and it may become practical to seek a court order of specific performance. But, perhaps a better way would be for E-Bay to create a new class of "Bonded Buyers and Sellers", in which E-Bay has credit card numbers from both buyer and seller, and both buyer and seller have agreed to binding arbritration by a 3rd party [E-Bay]. A bonded seller could designate an auction as open only to bonded bidders, with the assurance on both sides that the transaction WOULD be completed and that items offered would be as described.

25 years, 3 months

Rebirth of IMSAI

by edick＠idcomm.com

Unfortunately, the adoption of the IEEE696 standard was more or less, the cause of its demise. Whereas pre-696 board makers went to great lengths to make their products work with a range of CPU's, memory, FDC's, HDC's, I/O cards, etc, after the standard was adopted, these manufacturers used the standard as an excuse to ignore the others in the industry and the result was that interoperability suffered. If you want a current-generation computer with a useful front-panel display, you have to synthesize a single-step operation and dump the internals of the processor to the display hardware. Too much of the operation is packed inside the processor IC. If it's the front-panel you're after, and if you don't mind that the front panel needs to be shielded to meet FCC standards, as does the cabling you'll need, else you'll knock out all the broadcast TV reception in your neighborhood. Once that happens you'll have that ugly FCC van parked across your driveway. . . If you're bent on having an S-100 bus, it would work better to use an 8080 than a Z-80, as the S-100 signals were designed around an 8080. Most of the logic found on typical Z-80 cards for the S-100 is to regenerate those awkward and not terribly useful signals which Intel, Zilog, and others spent megabucks to eliminate so they'd be there to make the S-100 go. In this one respect, and recognizing the fact that hindsight is always 20-20, I'd say that Multibus-I was designed a lot better for general purpose computing. If you're really interested in running a "clever/new" S-100, you might try building a pod with which to emulate the 8080 processor from your PC. Old Intel documents will provide the desired timing, and I don't really think you need too fast a PC to emulate the old 8080 in real time. Writing the code to interpret the 8080 code correctly and produce the appropriate signal flow will show you definitely understand the workingsof the processor. You can even build a virtual front panel on your PC's CRT. Additionlly, you can run a window of "Hyperterminal" to support your need for a terminal with which to talk to the S-100 box as a console. I just took a look to see what I've got that would be interesting to integrate into a system on one of the big S-100 cardcages I've been hoping someone would take away. I must've hit my head . . . Dick -----Original Message----- From: John Ruschmeyer <jruschme(a)exit109.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Sunday, March 21, 1999 5:51 PM Subject: Re: Rebirth of IMSAI >> Why not create a current design for a modern front panel system? ok, retro >> styling because I like the silk screening of the 8800b and the 8080 but with >> *some* modern accoutrements while still providing that front panel >> experience. > >To me, that seems the best compromise between the extremes in this discussion. >Design a state-of-the-art S-100/IEEE-696 box and cardset (Z-80 based) >including an FDD controller which could use a standard 3.5" drive, offer >the whole thing as a kit with bundled CP/M (or clone). > >Sort of like the difference between a concours restoration of a Shelby >Cobra and one of the Cobra kits. > ><<<John>>>

25 years, 3 months

SWTPC and NETRONICS Parts

by terryf＠intersurf.com

Hello folks: HEADS UP FOR COLLECTORS I have the following items. If anyone is interested, drop me an email, if not they will go to eBay. I must stress that I would consider these "PARTS ONLY", I do not intend to represent them as any thing in working condition. While they may work, they are AS IS! SWTPC: AC-30 Tape interface (dual tape IIRC) card MP-A2 CPU card SSB M-16-A Memory card MP-LA Com (IIRC) card MP-B Motherboard MP-P Power supply card (cap and bridge included) Lower Case Half (front, rear, and bottom pan -- Faceplate and 2 buttons included) NETRONICS ELECTRONIC EXPLORER (case, power supply, motherboard) PROFESSIONAL ASCII TERMINAL (appears to have been modified) SOLID STATE MUSIC MB7 - 16K Ram card These items will go to eBay at < $10.00 each if nobody snags em first, the dumpster if nobody grabs them there. Terryf(a)intersurf.com

25 years, 3 months

Victory! (was: seller's market)

by yakowenk＠cs.unc.edu

On Sat, 20 Mar 1999 Sellam Ismail <dastar(a)ncal.verio.com> wrote: ] On Sat, 20 Mar 1999, Mike Ford wrote: ] > >emotions and how they affect bidding in an auction. All these factors ] > >contribute to the artificial inflation of prices. ] > I disagree with your premise that the auction is artificial or unfair. What ] Ok, you disagree with my premise. Care to provide any particular points ] ] > I don't understand is how you plan to stuff the genie back in the bottle. ] Which is exactly why I rail against ebay so much. If there's a price Crap. This is an easy topic to ramble on about. I just deleted a five page reply. No point in that; truth shouldn't be so hard to express. Now I've re-written it, and it is only 4.9 pages. :-) E-bay is just an open market, with all the same benefits and flaws. With Altairs and IMSAIs, we're seeing scarcity combined with ignorance. Marketers hype it up, of course, the few available units go to the highest bidders, of course, those bidders are not always veteran computer geeks, of course, and they can get overexcited and pay too much, of course. The shops that sell stuff at less-than-ebay prices are doing so out of ignorance. If you don't believe it, point them at e-bay, and wait. We've enjoyed garage-sale prices for a long time, but now there is growing public awareness of this stuff's value. (Due at least in part to our own efforts!) You didn't expect the world to say "Gee, this stuff is great! Lets sell it cheaper than ever!" Did you? With public awareness has to come higher prices, as well as people who are in it just for money, ready to exploit any weakness in any buyer. Think of it as a partial victory. People are paying attention, and no longer throwing away this stuff just because it is old. The next step has to be (more) education: it is not just Altairs and IMSAIs that are valuable. And they are not valuable just because of scarcity, but also because they are a snapshot of history, and because they are fun to use, play with, and experiment on. Now how do we get the word out?... Maybe some kind of high-publicity annual event, like an "Old Computer Faire", or "Retro Computer Bash", or.. Hey, I've got it, "Vintage Computer Festival!" Yeah! That's the perfect title! Part of the publicity could be to increase the public's awareness of more than just the monetary aspect of the machines, and make them see that Altairs and IMSAIs were just two instances in a horde of other equally-valuable machines. Maybe highlight the coolness of other particular classic machines, including some that are less scarce. Overall, prices are still likely to go up, but at least the going rate for each machine might be more in-line with its value relative to other machines, instead of "Altair/IMSAI 1, others 0". Finally, point out that current super-high prices are a fluke, because while there is no flood of these machines, there is a constant dribble; so smart buyers will wait, prices will drop, and early buyers will be left holding the bag. Of course, if you want prices to go back down to garage-sale levels, then you should instead give away (not sell!) your collection, sit quietly, and deride anyone who shows any interest in anything older than this year's Wintel. It won't succeed all the way, of course, but it might lower prices a little. So, what's the vote? Do we want lower prices, or public awareness? Cheers, Bill.

25 years, 3 months

FREE: Vic-20

by fpp＠concentric.net

Wow, I have always wanted a vic30. If you still have it I'd love it. I have several Apple IIc if youd like one.

25 years, 3 months

H11 vs H11A ?

by cmcmanis＠mcmanis.com

Heathkit folks, What does the "LTC" switch do on an H11A ? Which is more common? (H11 or H11A) Can an H11 be "upgraded" to an H11A? --Chuck

25 years, 3 months

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test-drb March 1999