- test-drb@ccmp.vtda.org - classiccmp.org

Can someome explain how arithmetic works?

by CLASSICCMP＠trailing-edge.com

Daniel Seagraves wrote, in his classic style of leaving the body of the message devoid of any any actual context as to what he's asking about and requiring a reference to the Subject line: >Subject: Can someome explain how arithmetic works? >Need this for my emulator, and nobody can explain to me how it works, and >I can't find any documentation that's useful to me. Specifically, I need stuff >like "you shift left and then check the last bit" etc. etc. Basically, I have >a bunch of ones and zeroes and I have to know how to add/subtract/multiply/ >divide with them. A *very* popular book for introducing this subject to students these days is _Computer Arithmetic: Algorithms and Hardware Designs_, by Behrooz Parhami. It's a pedantic, general purpose introduction, with an emphasis on conveying a true understanding of the subject through how the bits are actually banged about. An even more pedantic introduction is Donald Knuth's _The Art of Computer Programming, Vol 1: Fundamental Algorithms_. It's probably not so good as a introduction if you're really unfamiliar with the subject already, but it's a true classic in the field, and anyone who has worked in the field goes back to it every so often for some deep insight. For example, I just browsed through it a couple days ago for some grokking of how negative number base arithmetic works. Neat feature: no sign bit necessary! Another good reference, if you've already got some experience with computer architecture books and want to leverage this knowledge, is the IEEE Tutorial titled simply _Computer Arithmetic_ and edited by Earl E. Swartzlander. There's also Kai Hwang's _Computer Arithmetic: Principles, Architecture, and Design_ and Israel Koren's _Computer Arithmetic Algorithms_. I suspect that you just want a cheat-sheet for a few specific applications, in which case there's probably a Schaum's outline paperback that will get you by but without conveying any real understanding about how it works or why it works the way it does. I'm sure your local library has some similar workbook-style textbooks. Perhaps intermediate between the dumbed-down level of Schaum's Outlines and the high-and-lofty ivory tower view of Knuth would be a good numerical analysis text intended for scientists who have to learn the basics of how computers do arithmetic, and how this differs from traditional school-book arithmetic. _Numerical Recipes_ doesn't quite fit the bill, but when I was an undergrad I took several numerical analysis courses and all the textbooks had good, but terse, introductions to computer arithmetic, both fixed and floating-point. Again, I'm sure your local library has some good books. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 1 month

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Woz and his 6 chips...

by paulrsm＠ameritech.net

---------- > From: Mike Cheponis <mac(a)Wireless.Com> > To: classiccmp(a)classiccmp.org > Subject: Re: Woz and his 6 chips... > Date: Friday, June 02, 2000 12:14 AM > > Ladies & Gents, now I -gotta- know: What were those 6 chips, and is there a > schematic somewhere? If you want to see a nice picture, see eBay auction 341188950 (ends June 3).

26 years, 1 month

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ASCII Art Golden Gate Bridge & Plane

by dastar＠siconic.com

I took a photo of an ASCII art poster I have featuring the Golden Gate bridge and an airplane flying over it: http://www.siconic.com/crap/ascii_bridge.jpg It's made of up roughly 7 x 8 squares of wide carriage printer paper and is roughly 9 feet wide by 7 feet high. It's yellowed with age because it had been hanging on the wall of the person who originally printed it for I believe a couple decades or so. Sellam International Man of Intrigue and Danger ------------------------------------------------------------------------------- Looking for a six in a pile of nines... Coming soon: VCF 4.0! VCF East: Planning in Progress See http://www.vintage.org for details!

26 years, 1 month

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ASCII Art Golden Gate Bridge & Plane

by pete＠dunnington.u-net.com

On Jun 2, 15:23, John Foust wrote: > I think this is on an RSX ASCII collection tape I got from > someone or somewhere. In the "readme" FILENN.IDX, it's the > largest file: > > FILE14.LST 12,405 * Golden Gate Bridge > > where 12,405 records translated to 1,659,857 bytes. I'd be > glad to send a zipped version to anyone who wants it. > > By comparison, the popular Moon picture is 950,283 bytes, and > the Einstein is 348,400 bytes. I'd like copies of these, if you can make them available... -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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OT: Looking for Cap'n Crunch 2600Hz whistle

by dastar＠siconic.com

I'm looking for one of the original Cap'n Crunch cereal whistles that could produce the 2600Hz tone. If you know the story of John Draper (a.k.a. Cap'n Crunch) then you know what I'm talking about. I'd also like to get a hold of the box the whistle came in. I'm also looking for the October 1971 issue of Esquire magazine that featured the article with John Draper talking about the "blue box". If anyone has any idea where I might find these items, please e-mail me directly at <sellam(a)vintage.org>. Thanks! Sellam International Man of Intrigue and Danger ------------------------------------------------------------------------------- Looking for a six in a pile of nines... Coming soon: VCF 4.0! VCF East: Planning in Progress See http://www.vintage.org for details!

26 years, 1 month

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AppleSoft BASIC

by foo＠siconic.com

Here's something I pondered the other day: Why is AppleSoft BASIC called "AppleSoft" BASIC? ^^^^ Does this have something to do with the fact that Microsoft designed it? I can't think offhand of any other Apple software product that fell under the designation of "AppleSoft". Something tells me Eric may know this. Sellam International Man of Intrigue and Danger ------------------------------------------------------------------------------- Looking for a six in a pile of nines... Coming soon: VCF 4.0! VCF East: Planning in Progress See http://www.vintage.org for details!

26 years, 1 month

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OT: Archiving data (LONG)

by jfoust＠threedee.com

Regarding recording data on analog 35mm film, below is a recent excerpt from a microscopy mailing list, where people were discussing the use of film to record detail, as opposed to CCD imaging techniques: > To begin to answer Jeremy's question directly, we need to know > how much detail a Technical Pan negative can record. The figures > depend on processing technique and the test object luminance and > contrast, but the modulation transfer function figures published by > Kodak indicate that a spatial frequency in excess of 200 cycles per > mm is easily recordable. For a test object with contrast 100:1 they > quote 320 line pairs per mm. The CCD pixel spacing required to > achieve this feat would be 640 pixels per mm. That equates to a > requirement for 15360 x 23040 pixels to match the resolving power > of a 24x36mm Technical Pan exposure. That's 0.35 Giga pixels in > round numbers. - John

26 years, 1 month

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Looking for data sheet for Zilog 8530 Serial chip

by allisonp＠world.std.com

>A search of the web yielded lots of links, but no datasheet. I want to know >how to program it and its electrical characteristics. You know, the stuff >on a datasheet. Zilog's web site doesn't have it. 8530 is the Zilog SCC chip, as is the 8030. The differ only in bus interface. The 8530 is the non multiplexed bus part. It's a dual channel serial device with DMA and interrupt logic for Z80 series cpus. Programming of the functions are similar to Z80 SIO and related parts in a general way. It's a nontrivial device to use. Contact Zilog for data or check their page under SCC. >[ Its the chip used in the Apple Lisa and Mac and LOTS of other devices. ] You sure of this?? It's not really friendly to the 68k buses. Allison

26 years, 1 month

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Defining Disk Image Dump Standard

by xds_sigma7＠hotmail.com

Hmm, if someone writes a way to do all the archiving, I'd be happy to provide my 4381 for some serious processing power ;p Will J ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

26 years, 1 month

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Please help ID this Mac board--I hope it's old enough for the list!

by dhquebbeman＠theestopinalgroup.com

Sounds like a cache card for a PowerPC-based Mac. -dq > -----Original Message----- > From: Stan Perkins [mailto:stan@netcom.com] > Sent: Thursday, June 01, 2000 6:22 PM > To: classiccmp(a)classiccmp.org > Subject: Please help ID this Mac board--I hope it's old enough for the > list! > > > Hello all, > > I just came across this small PCI type board, labeled: > > APPLE COMPUTER INC. > 820-0510-A c1993 > > It also has a chip on it with the label: > > 341S0021 > c 1983-93 Apple > ^ > | > |-----That's why I'm hoping it's old enough to qualify :-) > > Anyway, on one side of the PCB it's got four large quad flat > pack chips, > from Philips, TI, VLSI, and BT, and on the other side (with the Apple > labeled chip I mentioned earlier) it has two rows of 8 each Toshiba > TC528128BJ-80 RAM chips. On the back end it has a DB-15F > connector (like > the old Apple monitor connector) and two round DIN connectors > labeled "S > IN" and "S OUT" with 7 female contacts each. > > It came in a box labeled DOS Compatibility Card for Macintosh, but I'm > beginning to think it's not. > > Any clues are greatly appreciated! > > Thanks, > Stan >

26 years, 1 month

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Tech Rumors/Legends?

by dhquebbeman＠theestopinalgroup.com

> I don't think that would work. I've cooked EPROMs for months > without any change in their functioning. So did a partner of mine.... using a homemade eraser made from a UV sterilizer unit taken from a scrapped dialysis machine. It was an Intel eprom, a 2732 or 2764, ceramic case, quartz window. The embedded system we were developing was an auto- mated knife sharpener (not to be a consumer product). During debugging, we had the prototype out of the case. Things were working fine and it was time for the first install into the van (which would drive from restaurant to restaurant doing the knife sharpening thing). Put unit in case, fire up, no operation. Take unit out of case, fire it up, everything works. We looked for warping of the PC board, kinking of cables, and all sort of things that coould glitch the unit out. Nada. Finally, thinking that we were only going to see how the case was screwing with the PC board from inside the assembled unit, we cut an access panel in the aluminum, and shined a flashlight inside. It happened to hit the EPROM window and voila! the unit starts running. After a long call with Intel engineers, it was determined that too much UV could fry the EPROM such that it would only function correctly when light was shining onto the substrate through the window! An EPROM that was afraid of the dark. To get the prototype out the door, we built it a night-lite, and everything was fine. -doug quebbeman

26 years, 1 month

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Defining Disk Image Dump Standard

by allisonp＠world.std.com

>Sellam Ismail <foo(a)siconic.com> writes: >> But can you dedcode 6&2 encoded bytes in realtime on a 6502? Something >> tells me it's not fast enough to do this. > >If you're clever enough, you can do it. I previously cited several packages >that did it. Cant speak for the 6502, but NS* did it with minimal hardware a few years earlier and it was a respected design. Not a whole lot of ttl on the board either considering it was S100, Boot prom and FDC. Allison

26 years, 1 month

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OT: Looking for Cap'n Crunch 2600Hz whistle

by SUPRDAVE＠aol.com

In a message dated 6/2/00 2:31:30 AM Eastern Daylight Time, foo(a)siconic.com writes: > On Fri, 2 Jun 2000, David Vohs wrote: > > > I'm sorry I can't help you find one. But I hope that you are looking for > > them only for their collectable value. I think that AT&T, and any other > > phone company, has probably long since removed this nice little "feature" > > from the computers that run the lines. So if you're looking to make some > > free phone calls, I don't think it will work. But then again, I don't work > > > for a phone company, so I could be completely wrong on this. > > C'mon, give me a break. I don't even think the youngest of fools can be > that naive :) > > No, this is purely for historical reasons. I'm developing an exhibit > around the now legendary (and now very useless) "blue box". > > Sellam back then, the telco used electromechanical systems which were easy to hack and get away with. nowadays, it's electronic with much more automation and security so its harder to cover one's tracks. i think red boxes still work, but some COCOTs have been modifed to prevent this. DB Young hurry, hurry, step right up! see the computers you used as a kid! http://members.aol.com/suprdave/classiccmp/museum.htm

26 years, 1 month

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HP 7000 - What is it?

by mrdos＠swbell.net

Does anyone know anything about a HP 7000 Series computer? I don't know a lot about old HP systems. Do y'all think it's worth getting? Thanks, Owen

26 years, 1 month

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OT: Looking for Cap'n Crunch 2600Hz whistle

by netsurfer_x1＠hotmail.com

>I'm looking for one of the original Cap'n Crunch cereal >whistles that >could produce the 2600Hz tone. If you >know the story of John Draper >(a.k.a. Cap'n Crunch) then >you know what I'm talking about. > >I'd also like to get a hold of the box the whistle came >in. I'm also >looking for the October 1971 issue of >Esquire magazine that featured the >article with John >Draper talking about the "blue box". > >If anyone has any idea where I might find these items, >please e-mail me >directly at <sellam(a)vintage.org>. > >Thanks! > >Sellam International Man >of Intrigue and >Danger >--------------------------------------------------------->---------------------- >Looking for a six in a pile of nines... > > Coming soon: VCF 4.0! > VCF East: Planning in Progress > See http://www.vintage.org for >details! I'm sorry I can't help you find one. But I hope that you are looking for them only for their collectable value. I think that AT&T, and any other phone company, has probably long since removed this nice little "feature" >from the computers that run the lines. So if you're looking to make some free phone calls, I don't think it will work. But then again, I don't work for a phone company, so I could be completely wrong on this. Best of luck either way. ____________________________________________________________ David Vohs, Digital Archaeologist & Computer Historian. Home page: http://www.geocities.com/netsurfer_x1/ Computer Collection: "Triumph": Commodore 64C, 1802, 1541, FSD-1, GeoRAM 512, Okimate 20. "Leela": Macintosh 128 (Plus upgrade), Nova SCSI HDD, Imagewriter II. "Delorean": TI-99/4A. "Monolith": Apple Macintosh Portable. "Spectrum": Tandy Color Computer 3. "Boombox": Sharp PC-7000. ____________________________________________________________ ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

26 years, 1 month

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Please help ID this Mac board--I hope it's old enough for the list!

by jruschme＠mac.com

> From: Stan Perkins <stan(a)netcom.com> > Subject: Please help ID this Mac board--I hope it's old enough for the list! > > Hello all, > > I just came across this small PCI type board, labeled: If it's what I think, it's actually a PPC 601 PDS (processor direct slot) card. > APPLE COMPUTER INC. > 820-0510-A c1993 > > It also has a chip on it with the label: > > 341S0021 > c 1983-93 Apple > ^ > | > |-----That's why I'm hoping it's old enough to qualify :-) Not that old... but none the less... > Anyway, on one side of the PCB it's got four large quad flat pack chips, > from Philips, TI, VLSI, and BT, and on the other side (with the Apple > labeled chip I mentioned earlier) it has two rows of 8 each Toshiba > TC528128BJ-80 RAM chips. On the back end it has a DB-15F connector (like > the old Apple monitor connector) and two round DIN connectors labeled "S > IN" and "S OUT" with 7 female contacts each. Sounds like the AV card for the 1st-generation (NUBUS) PowerMacs (6100/7100/8100). > It came in a box labeled DOS Compatibility Card for Macintosh, but I'm > beginning to think it's not. More likely, someone removed it from an AV 6100 to install the DOS card. Interesting find, though... > Any clues are greatly appreciated! You're welcome. <<<John>>>

26 years, 1 month

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Defining Disk Image Dump Standard

by yakowenk＠cs.unc.edu

My two cents, in decreasing order of sanity. Maybe it's a little far from the original goal*, but for the cost of a few extra bytes in track/sector numbers, the same format might handle the contents of hard disks. And there's probably a lot fewer "whacko" formatting concerns with those than with floppies - 99.44% of the time, just getting a big pile of sectors might be as much as you'd need. AFAIK, nobody wrote quarter-tracks on hard disks, or tried to copy- protect software by making bad sectors, or any similarly-goofy stuff. And machines that used hard disks didn't generally fixate on the number of tracks or sectors. (How much of that is true? Discussion?) My reaction to XML et al is generally negative too, and also not for any good reason that I could put my finger on. Maybe it seems like it would be work to parse, and I like to imagine my poor old 8-bitters being able to make use of the images themselves, not just the recipients of an end-product that was produced by a modern machine that digested the image. As I said, it's not entirely a rational concern; those old 8-bitters could do it just as well as any modern machine, given enough time and storage and programming... Maybe that's it, coding up an XML parser for a CoCo seems like it would be much more work than having some byte-by-byte record definition. So maybe you XML supporters need to hit that point a little harder. Speaking of which, maybe some compressed representation of repeated identical sectors could be good. If a floppy was 10% full, and the remaining sectors were full of some "empty" byte pattern, It would be nice if those "empty" sectors didn't take up space in the image. Of course, the image could just omit sectors, but then you'd need intelligence to decide which sectors to omit; almost as bad as needing to know which files to keep. The only way to be safe is to get it all, and maybe take advantage of patterns in the data to compress it a bit. Then again, if I care about image size, I suppose I could always use any standard compression utility on the image. And then I'd want to get decompression going on the TRS-80... Okay, I think it's time to stop babbling. Bill. * I'm _not_ going to make any bad puns about being on the wrong track. :-) On Thu, 1 Jun 2000 13:34:55, Sellam Ismail <foo(a)siconic.com> wrote: ] Current iteration: ] ] Desk Descriptor Header ] ] 1. Host computer type (2 bytes allowing up to 65536 models to be specified) ] 2. Hard/soft sector flag (1 byte) ] 3. Number of tracks (1 byte) ] 4. Disk drive RPM (2 bytes: 1 for whole number, 1 for fraction) [1] ] ] Optional: ] ] 5. Archiver Name (24 bytes) ] 6. Archiver E-mail Address (48 bytes) ] 7. Disk Title (64 bytes) ] 8. Publisher (if applicable) (24 bytes) ] 9. Year of Publication (2 bytes) ] A. Archive Description (256-512 bytes) ] B. Archive Date (4 bytes: 2 bytes = year, 1 byte = month, 1 byte = day) ] C. Archive Time (3 bytes: hour, minute, second) ] ] ***Does it make sense to have separate fields as specified #7-9 or should ] we rely upon the archivist to include that data in the description? I ] think so since this is important information that should be forced to be ] included with the archive. ] ] Maximum size: 685 bytes ] ] [1] If applicable ] ] Note: Encoding type moved to Track Descriptor Header ] ] ] A Track Descriptor Header will precede each track and give an overall ] description of the track: ] ] Track Descriptor Header ] ] 1. Track number (2 bytes: 1 for whole number, 1 for fraction) [1] ] 2. Disk Side (1 byte) ] 3. Track format (logical or raw; host computer specific) (1 byte) [2] ] 4. Track size in bytes (2 bytes) [3] ] 5. Sector format (single-density, double-density, etc) (1 byte) ] 6. Encoding type (1 byte) ] 7. Sectors in this track (1 byte) ] 8. Interleave (1 byte) ] 9. Bytes per sector (2 bytes) ] A. Bits per byte (1 byte) ] B. Offset to next Track Descriptor Header (2 bytes) ] ] Size: 15 bytes ] ] [1] Fraction allows for specifying half- or quarter-track. ] [2] If the track is in "raw" format then fields 3-9 are ignored. ] [3] The total size in bytes of the raw track image. ] ] ] I can start to see where the flexibility afforded by a markup language ] makes sense. I just can't figure out why I am still resisting it though. ] ] So, are we on the right track? The wrong track? ] ] Sellam International Man of Intrigue and Danger ] - ------------------------------------------------------------------------------- ] Looking for a six in a pile of nines... ] ] Coming soon: VCF 4.0! ] VCF East: Planning in Progress ] See http://www.vintage.org for details!

26 years, 1 month

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Defining Disk Image Dump Standard

by pete＠dunnington.u-net.com

On Jun 1, 11:10, Sellam Ismail wrote: > On Thu, 1 Jun 2000, Pete Turnbull wrote: > But a lot more volumnious. But this is just my prejudice speaking. Even > though I find HTML useful, I hate it. It needn't be a whole lot more voluminous. The tags should be concise, there's no need to write an essay for each part. Keywords might be a good idea. Tags would be omitted if irrelevant (as many would be for a "raw" archive, or for a common format with no "funnies"). So a disk descriptor might look something like this: {Apple ][<00>soft<00>trks:<40><00>rpm:<15><255><00>{trk:<00><00>logical<00> length:<12><34><00>sectors:<10>{sector:<00><00>{sync{bytes:<16><00>value:<255><00>}{header:GCR<00>trk:<00><00>sec:<00><00>physsec:<00><00>head:<00><00>size:<00><01><00>}{data:< ---256 binary bytes---- >crc:<xx><xx><00>}}sector: [repeat as reqd] }}{track: [repeat as reqd] }} I can't remember some details like the size of a DOS 3.3 track or what the sync bytes are so that's just an stylistic example. The opening "{" marks the start of an object and is matched by a closing "}"; braces are nested because objects are nested. Variable-length strings like "Apple ][" are terminated by some agreed control character (I used ASCII NUL, <00>). Numeric values are stored in binary (actually it might make more sense to store them in ASCII where they follow a string description, but probably not for a block of sector data). So "rpm" is stored as a 2-byte representation of 360. Hmm, we'd need to decide if it's little-endian or big-endian -- or add another tag! > > a problem? The tags don't all need to be ASCII text, things like the > > sector size could be integers, and field lengths could be limited. I'd > > envisage something like nested objects (borrowing from Sellam's slightly > > later mail): > > I don't like the idea of storing the actual sector data as text though. I hadn't meant to imply that; I mean you could hexify it if you wanted, but I don't see any need. Actually one of the things I was thinking of earlier today, was Acorn's "DrawFile" format, which uses similar objects, but the data is still binary (it's a computer program that reads the data, not a human). If a human really did need to read it, you could always use a hex editor. > I guess in this > day and age it doesn't matter much anymore but when I was growing up you > had to make every byte count, and I know more than 95% of us here can > relate to that. Yup, I was too, but I think here the benefits greatly outweigh the disadvantage of extra storage requirement. We want this to be as useful as possible, and the easier it is to use for unexpected formats (to create *and* to read), the more it will get used. > > It also > > means that if the database is lost, damaged, incomplete or otherwise > > inaccesible, an archive can still be understood, and there's no chance of > > inconsistency because two people tried to add new formats at about the same > > time, or someone rolled their own. > > I agree with that. Human readability is definitely a compelling advantage > as is the elimination of the need for a centralized database of system > descriptions. It would still be good to have a central repository. At the very least, it would allow those who know where to look, to see what has already been dealt with, and save a lot of design effort if the format they want is already there. It would be the place to store the explanation of the tag system. Plus, the bigger it gets, the more it will encourage others to archive their treasures, too. -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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Defining Disk Image Dump Standard

by allisonp＠world.std.com

>I also like the inductive matrix ROM used in the HP9100. It works by the >coupling between 512 address tracks and 64 data loops in a 14 layer (?) >PCB. The PCB is about 4" square and stores 512 words, each one 64 bits >long. It is _very_ reliable -- 9100s are now about 30 years old, and >while I've had to replace transistors and diodes in them, I've never >heard of the ROM failing. I Gotta get me one of those, they are so likeable. Allison

26 years, 1 month

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Finds

by mcguire＠neurotica.com

On May 31, Zane H. Healy wrote: > Of course since I have a 60Mhz RS/6000 on my desk at work and refuse to > give it up for a state of the art single or dual processor PC my opinions > of acceptable speed might be a little outside the norm :^) > > Remember for most things stability is more important that speed. While I agree 100%, it would seem that the unfortunate proliferation of PeeCees have all but killed that mindset. I suspect that most of us fight very hard to keep it alive. But...on the term "acceptable speed"...isn't that completely subjective? I mean, what's acceptable to you might be too slow for Joe Blow, or uselessly fast for Jane Doe...Intel would have us believe that we all do the exact same thing with our computers, and that the only possible thing that we should find acceptable is *their* brand of high-performance...i.e. blindingly fast until you try to do more than one thing at a time, then it goes into the toilet. Man, if your RS/6000 does the job, and you like it, then keep it, and more power to you! -Dave McGuire

26 years, 1 month

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Tech Rumors/Legends?

by pete＠dunnington.u-net.com

On Jun 1, 13:33, Doug Coward wrote: > 2. About 1982 I started hearing that it was possible to > build a camera for your pc by "cooking" an EPROM under > UV light for an extended period until the memory cells > were still light sensitive but would no long hold a > charge. Then by placing a len over the EPROM's window, > you had a real time low-res video image mapped right into > memory. Again this is one that quite a few people had > heard about but no one knew anyone that had ever done it. I've not heard of an EPROM used this way, but DRAMs certainly have been. It's possible, with care, to remove the metal lid from some ceramic-packaged DRAMs and add a lens. The memory cells are light sensitive; the more light, the faster the charge leaks away, so the scheme is to write 1's into all locations, pause, then read them back. Unfortunately, on most DRAMs, the relationship between logical address and physical location in the array is not simply "add 256 for the next row", so some decoding is necessary. However, at least one DRAM does have such a simple mapping, and was sold for the purpose. I'm sure it was described in one of Steve Ciarcia's Circuit Cellar articles in Byte, around 1982, but I can't find it amongst my reprints. Anyone? -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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Tech Rumors/Legends?

by netsurfer_x1＠hotmail.com

>Nice little summary article. > >From that: > >"Aquarius > >Mattel > >When Mattel demonstrated this computer at a trade show >in 1983, employees >had to conceal one of the keys with >masking tape. For some bizarre reason >known only to >Matte l engineers, the Aquarius had a convenient key >that >instantly rebooted the computer and wiped out all >your data." > >It was called the RESET key and I hated it. They at >least designed a >little ridge around it so it was harder >to accidentally press. However, I >remember you could do >a CTRL-C or some other control key sequence and >"undo" >the RESET (basially it would cancel the reset and put >you back >where you just were). > >When you first turned the Aquarius on, you had a little >intro screen that >said whatever, something like "Mattel >Aquarius" ... "Press any key to >continue". When you >pressed a key it initialized BASIC and plopped you >into a prompt. > >Pressing the RESET key apparently didn't erase the >memory but just took >you to the initial startup screen, >so it was made possible to back out of >a RESET using the >control key sequence. > >Sellam International Man >of Intrigue and >Danger >--------------------------------------------------------->---------------------- >Looking for a six in a pile of nines... > > Coming soon: VCF 4.0! > VCF East: Planning in Progress > See http://www.vintage.org for >details! One thing I'm surprised that did not make it onto that list it the Macintosh Portable (it probably was #21 or thereabouts). If the DG/1 required Superman to pick it up, I don't want to know who they would have required to pick it up! ____________________________________________________________ David Vohs, Digital Archaeologist & Computer Historian. Home page: http://www.geocities.com/netsurfer_x1/ Computer Collection: "Triumph": Commodore 64C, 1802, 1541, FSD-1, GeoRAM 512, Okimate 20. "Leela": Macintosh 128 (Plus upgrade), Nova SCSI HDD, Imagewriter II. "Delorean": TI-99/4A. "Monolith": Apple Macintosh Portable. "Spectrum": Tandy Color Computer 3. "Boombox": Sharp PC-7000. ____________________________________________________________ ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

26 years, 1 month

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VMS media availability for VAX 8530

by xds_sigma7＠hotmail.com

Well, if you seek to install VMS 5.2, then you have no problem... simply kindly ask me for the use of my VMS 5.2 RL02 stand-alone backup cartridge, never used, was sealed in the box when I got it... And no, the shock meter was NOT red ;p Will J ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

26 years, 1 month

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Rumor/Legend #3

by xds_sigma7＠hotmail.com

Welllll... as for the whacked out missing-corner looking disks, I can confirm this... I have an ancient Memorex 651 floppy disk drive, and this thing is circa 1973-74.. And those are the disks it uses... it CANNOT use "normal" disks. FYI, there are at least two types of those disks, FD IV and FD V, not sure what the diff is but I will look it up in the manual later tonight. I have around 40 or so of those weird disks... They are also notable (IMHO) for being freakishly colored... Indeed, you can easily tell FD IV's and FD V's apart by the fact that FD IV disks are icky 70's orange, while FD V disks are a funky dark blue sort of color. I actually have 3 other clone disks from Information Terminals (the chicken company!) too, but I couldn't tell ya if they're FD IV or FD V clones.. Will J ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

26 years, 1 month

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Please help ID this Mac board--I hope it's old enough for the list!

by mcguire＠neurotica.com

Sounds like a video frame grabber to me... -Dave McGuire On June 1, Stan Perkins wrote: > Hello all, > > I just came across this small PCI type board, labeled: > > APPLE COMPUTER INC. > 820-0510-A c1993 > > It also has a chip on it with the label: > > 341S0021 > c 1983-93 Apple > ^ > | > |-----That's why I'm hoping it's old enough to qualify :-) > > Anyway, on one side of the PCB it's got four large quad flat pack chips, > from Philips, TI, VLSI, and BT, and on the other side (with the Apple > labeled chip I mentioned earlier) it has two rows of 8 each Toshiba > TC528128BJ-80 RAM chips. On the back end it has a DB-15F connector (like > the old Apple monitor connector) and two round DIN connectors labeled "S > IN" and "S OUT" with 7 female contacts each. > > It came in a box labeled DOS Compatibility Card for Macintosh, but I'm > beginning to think it's not. > > Any clues are greatly appreciated! > > Thanks, > Stan

26 years, 1 month

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Defining Disk Image Dump Standard

by pete＠dunnington.u-net.com

On Jun 1, 16:34, John Wilson wrote: > On Thu, Jun 01, 2000 at 11:12:11AM -0700, Sellam Ismail wrote: > >Insert "Disk Side (Head)" (1 byte) > > Hard or soft head number? I feel sure I ran into a format (Commodore?) where > the sector headers had the opposite head numbers to the side on which they > were actually recorded. This is also true on some Acorn disks, and I'm sure I've run across it elsewhere, where the "head" value encoded in each sector header is always "0", because the second side is treated as tracks 80-159 instead of each cylinder being two tracks distinguished by head number. -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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Tech Rumors/Legends?

by mgregory＠vantageresearch.com

-----Original Message----- From: Doug Coward <dcoward(a)pressstart.com> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Thursday, June 01, 2000 2:41 PM Subject: Tech Rumors/Legends? >Hi All, > One the nice things about this list is the variety of >first hand experience that can be called upon to clear >up those nagging second hand rumors that you keep dragging >around for years, unable to track down a definitive answer. > >Up for review: >1. "The person that designed the Mindset PC later designed >the Amiga." I realize that computers like the Amiga are not >designed by just one person, but does anyone know anything >about the people that helped design these computers? I've never heard of the Mindset PC, but the Amiga story is very nicely told at The Amiga Interactive Guide, at www.amiga.emugaming.com . Follow the Features link, and see "Amiga History" and "The Amiga Corporation 1982-84". Although a team of designers was involved, the person generally credited as "the father of the Amiga" is the late Jay Miner, who came from Atari Corp. via Xymos.

26 years, 1 month

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Tech Rumors/Legends?

by mgregory＠vantageresearch.com

-----Original Message----- From: Sellam Ismail <foo(a)siconic.com> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Thursday, June 01, 2000 3:49 PM Subject: Re: Tech Rumors/Legends? > >When did Jay Miner pass away? > June 20, 1994. For a full bio, see http://www.jms.org/jay-miner.html Mark.

26 years, 1 month

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OT: Archiving data (LONG)

by CLASSICCMP＠trailing-edge.com

>I like the ideas about digitizing the stream of raw disk data. >I imagine it would be possible to perform some software-based >analysis and repair, rendering previously scrogged disks readable. >Or perhaps the forensic-style recovery of erased data, reading >and averaging adjacent off-center track information. > >I seem to remember a PDP guy on this list who recovers reel tape >data this way, digitizing the raw tracks and processing with >software, as opposed to relying on antique hardware methods for >decoding the stream. That would've been me, I think :-). It really is straightforward to do today - a PC, a few hundred dollars of investment for the A/D hardware and cabling, an old 9-track or 7-track drive that you can set up to spool forward at a constant rate, and you've got the hardware side done. The analysis software is where the real magic occurs - look up "PRML" in a good engineering or math bookstore and you'll be on the right path. Incorporating the data from non-flaky channels to recover the data in the flaky channel is easy for 1/2" magtapes because of the existence of both longitudinal and horizontal parity bits. The same techniques work for 8", 5.25", and 3.5" floppies, too. You don't have the luxury of parity channels there, but PRML techniques put you way ahead of traditional data separators. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 1 month

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OT: Archiving data (LONG)

by CLASSICCMP＠trailing-edge.com

>> >Yes, but how long can we expect the film to last? >> >> Decades, if processed sloppily, or centuries, if processed archivally. > >Sounds great, but how readily available is the process of film archiving >to hobbyists, how easy is it to master, and how much does it cost? This isn't rocket science; archival-quality film processing has been studied for most of a century already. Anyone capable of following the Kodak (or Ilford, or Agfa) directions and who has a kitchen sink, about $25 for hardware, and about $10 for photo chemicals can do it. No, it isn't the point-and-click interface you're used to, but some of us actually enjoy mixing chemicals and processing film and paper by hand. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 1 month

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Defining Disk Image Dump Standard

by foo＠siconic.com

Current iteration: Desk Descriptor Header 1. Host computer type (2 bytes allowing up to 65536 models to be specified) 2. Hard/soft sector flag (1 byte) 3. Number of tracks (1 byte) 4. Disk drive RPM (2 bytes: 1 for whole number, 1 for fraction) [1] Optional: 5. Archiver Name (24 bytes) 6. Archiver E-mail Address (48 bytes) 7. Disk Title (64 bytes) 8. Publisher (if applicable) (24 bytes) 9. Year of Publication (2 bytes) A. Archive Description (256-512 bytes) B. Archive Date (4 bytes: 2 bytes = year, 1 byte = month, 1 byte = day) C. Archive Time (3 bytes: hour, minute, second) ***Does it make sense to have separate fields as specified #7-9 or should we rely upon the archivist to include that data in the description? I think so since this is important information that should be forced to be included with the archive. Maximum size: 685 bytes [1] If applicable Note: Encoding type moved to Track Descriptor Header A Track Descriptor Header will precede each track and give an overall description of the track: Track Descriptor Header 1. Track number (2 bytes: 1 for whole number, 1 for fraction) [1] 2. Disk Side (1 byte) 3. Track format (logical or raw; host computer specific) (1 byte) [2] 4. Track size in bytes (2 bytes) [3] 5. Sector format (single-density, double-density, etc) (1 byte) 6. Encoding type (1 byte) 7. Sectors in this track (1 byte) 8. Interleave (1 byte) 9. Bytes per sector (2 bytes) A. Bits per byte (1 byte) B. Offset to next Track Descriptor Header (2 bytes) Size: 15 bytes [1] Fraction allows for specifying half- or quarter-track. [2] If the track is in "raw" format then fields 3-9 are ignored. [3] The total size in bytes of the raw track image. I can start to see where the flexibility afforded by a markup language makes sense. I just can't figure out why I am still resisting it though. So, are we on the right track? The wrong track? Sellam International Man of Intrigue and Danger ------------------------------------------------------------------------------- Looking for a six in a pile of nines... Coming soon: VCF 4.0! VCF East: Planning in Progress See http://www.vintage.org for details!

26 years, 1 month

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Defining Disk Image Dump Standard

by pete＠dunnington.u-net.com

On May 31, 22:05, Sellam Ismail wrote: > > Responding to an older message... > On Tue, 30 May 2000, Tony Duell wrote: [...] > > Which means the archive format would have to allow for : [...] > > It may be a _very_ unusual format, but a proposed archive format should > > be able to handle _anything_. Wel, I agree with that, so far as it's possible. > I suppose a sub-format byte wouldn't hurt. What I don't like about it is > that it will require that someone be maintaining a database of all the > sub-formats. But I guess since we have a machine identifier and this will > have to be maintained as well, a sub-format byte is not too demanding. > Of course, there will have to be a central person who is responsible for > receiving input for new machine and sub-format types, updating the > database with the new computer types and sub-format types, and > disseminating this from a website. That's part of the reason I think an encoded format is a bad idea. Hans' suggestion of a tagged format using XML (or something else) is much better. It allows for decoding without referring to a central archive, and it's much more flexible and extensible. Sure, it takes more space, but is that a problem? The tags don't all need to be ASCII text, things like the sector size could be integers, and field lengths could be limited. I'd envisage something like nested objects (borrowing from Sellam's slightly later mail): { Disk Descriptor Header, containing: Host computer type string "Hard"/"soft" sector flag Number of tracks (1 byte) Disk drive RPM ... { Track Descriptor Header, containing: Track number (with fraction) Track format "logical"/"raw" Track size in bytes Sectors in this track (1 byte) Offset to next Track Descriptor Header ... { Sector header descriptor, containing: Sector header format FM/MFM/GCR/... Sector data format FM/MFM/GCR/... [1] Sector number as encoded on the original disk Track number as encoded on original disk Head number as encoded on original disk Physical sector number Sector size ... { sector data (binary, hex-coded, whatever) } { Sector header descriptor } { sector data } } } The nesting tagging allows you to specify things like RX02 floppies, where the headers are FM but the data is MFM. It also allows you to specify different sector sizes on different tracks, or data written in the headers that doesn't match physical track/sector/side on the original. It also means that if the database is lost, damaged, incomplete or otherwise inaccesible, an archive can still be understood, and there's no chance of inconsistency because two people tried to add new formats at about the same time, or someone rolled their own. I've seen too many data formats where the decoding information was unavailable, or was hard to get, or was "location unknown at this time", or the prospective user simply didn't now where to look. If the information is in the archive itself, anyone can work out what do do with it, any time. -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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OT: Archiving data (LONG)

by dhquebbeman＠theestopinalgroup.com

> I'm one of the people who still does use paper tape for backup. Not for Any chance you have a spare reader you'd be willing to load? I'd be willing to put up a security desposit for its safe return... -dq p.s. Oh, it's 8-level paper tape, not 5-level (just making sure)...

26 years, 1 month

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IBM I/O Selectric/Posting Machine (Was RE: Atari 800 keyboard s)

by dhquebbeman＠theestopinalgroup.com

> How much do you want for it, and where is it? It sounds neat. I dunno... lemme think about it. Shipping is likely to be expensive! -dq

26 years, 1 month

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Papertape and Mylar variant

by dhquebbeman＠theestopinalgroup.com

> > Right-o... teletypes with the reader/punch used rolls of paper tape. > > I have a copy of DEC Monopoly on papertape that I punched myself, as > > well as a copy of Intel's INTERP-80 (8080a simulator) and a > Star Trek > > game called BIGMES (from an HP 2000). > > What machine did INTERP-80 run on? Was it written in BASIC? No, it was written in Fortan-IV. I ported it from its original generic source code to run on the CDC6600 under Kronos 2.1, a DEC-10 running TOPS-10, and lastly, a Prime P400 running Primos. > I'm currently writing a simulation of the hardware that HP 2000 TSB ran > on (a pair of HP 21xx minicomputers with a pair of bidirectional parallel > interfaces between them). I've typed in most of the source code to > 2000C' from a printed listing, and have written an assembler in Perl. I must say, that's pretty cool. I used to have some other HP2000 programs, but the only one I found the other day was a listing that I'd printed on a Silent 700 terminal. Environmental effects have darkened the thermal paper to make it nearly unreadable. A bit of squinting for a day or two might surmount that problem. > I'd be interested in getting copies of those paper tapes, and anything > else you might have that could be run on a 2000. Naturally I'm willing > to pay copying and postage costs. As I consider the paper tapes priceless, you'd have to be willing to put up a serious chunk of change in escrow in case anything happened to them. Better that you wait for me stage them to a newer format. > I'll make accounts on the simulated 2000 available once it's running. If you need BASIC programs to run on your simulator, keep a close watch on E-Bay for books of BASIC games. I saw David Ahl's book 101 BAsic Games the other day; that's for DEC-10 BASIC, but I recall there were some books on HP BASIC back way back when, so one of those books will doubtlessly surface. Another resource for HP 2000 programs would be old issues of Creative Computing (another wonderful magazine killed by the evil Ziff-Davis empire). Good luck; I'll file your message to me in my hobby folder so that I'll have your e-mail address, and once I finally get BIGMES on disk, I'll let you know. -doug q

26 years, 1 month

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Defining Disk Image Dump Standard

by pete＠dunnington.u-net.com

On May 31, 17:27, Mark Gregory wrote: > From: Pete Turnbull <pete(a)dunnington.u-net.com> > >Can I encode mine on knotted string? My mother has a box with an *awful* > >lot of string. Should I use the thicker string for DD disk archives? > If you want increase your data storage capacity, you could colour code the > string, too. > > Everything old is new again ... we've just re-invented the Inca quipu, a > few centuries on. I know. Aside from jibes at those who so vehemently insist that there should be one particular form of archive, I'm not sure anyone really knows how to read quipus, though. -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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New Vintage Computer Festival Website!

by vcf＠siconic.com

The new Vintage Computer Festival website is now up. http://www.vintage.org Yes, there are still some broken links (none of the foreign language links work for instance...translators needed) but these will be fixed shortly. I invite anyone and everyone to submit articles for publication on the VCF website on any topic having to do with vintage computers and computer history. A link to the article will appear on the home page guaranteeing you exposure. Much thanks goes to Hans Franke for developing the new design! VCF 4.0 dates should be announced within a week or so. Sellam International Man of Intrigue and Danger ------------------------------------------------------------------------------- Looking for a six in a pile of nines... Coming soon: VCF 4.0! VCF East: Planning in Progress See http://www.vintage.org for details!

26 years, 1 month

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VAX-11? and some C64 stuff

by mcguire＠neurotica.com

On May 31, Kenn Humborg wrote: > > Also, you'll need the special > > DEC monitor that goes with whatever station you are buying, you > > can't use a > > chincy PC compatable monitor with a VAXStation. > > However, a good quality multi-sync (i.e. modern) PC monitor > with BNC inputs will probably work fine. I'm using an > Iiyama Visionmaster 17 with a VAXstation 3500 (VCB02 video > adapter) with no trouble. > > (And I have my PC plugged into the VGA input, so I can switch > between VAX and PC using the monitor's front panel buttons.) The good thing, though, about using "original" DEC monitors on machines like those is that you can get a wonderfully HUGE tube with a deliriously tight dot pitch and fabulous video quality for next to nothing because they're fixed-frequency. The PeeCee world's inability to develop video systems that don't require changing sync rates every time the wind blows has afforded the Real Workstation world a wonderful advantage...a plethora of gorgeous, huge monitors that can be had for a song. :-) -Dave McGuire

26 years, 1 month

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Fw: VMS media availability for VAX 8530

by geoffrob＠stmarks.pp.catholic.edu.au

Following post from comp.sys.dec reposted to classic computers at request of originator. Anyone on the list that can help him? I have the Pro380 console and 5.25" media for an 8530 console, (and an 8530 - minus the console to vax cables) even VMS on 9 track, but I'm a bit far away... I initially thought this place was in Europe somewhere, but it seems it's actually in New York USA. I've mentioned the room heater effects of ECL based systems. ----- Original Message ----- From: "Derek Konigsberg" <konigd(a)rpi.edu> Newsgroups: comp.sys.dec Sent: Sunday, May 28, 2000 1:31 AM Subject: VMS media availability for VAX 8530 > Hello, > In the Electronics Club at RPI (Rensselaer Polytechnic Institute), > we've come across a number of old DEC machines. It all started with a > PDP-11/45, then we got a VAX 8530 that was being dumped. We also have > a VAXstation 4 (doesn't exist, but we have one, and it looks like a II > by the case design) and a VAXstation 3100. Anyways, the main problem > is the 8530. Our main RA82 hard drive doesn't spin up, and we can't > find the problem. We have other functional hard drives, but no means > of installing VMS on them. Basically, we need the tape for our TU81+ > tape drive (6250bpi, I think), and the 5-1/4" floppy disk to put in > the console to bootstrap the machine. Yes, for anyone who didn't > know, this machine requires a special "VAX Console" (no, it's not a > terminal) to tell the machine to power up and to download the > microcode. Anyways, right now the machine is an impressive metal > obstruction in the room until we get it operational. So, does anyone > have or know where we can find the right VMS media for this beast? > > P.S. Just wondering, but anyone know what thing thing sold for back in > '87 when it was new? > > Thanks, > Derek Konigsberg > RPI Electronics Club, President > konigd(a)rpi.edu > >

26 years, 1 month

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Defining Disk Image Dump Standard

by allisonp＠world.std.com

>> The way you separate the operating system from the executables is by never, >> Never, NEVER, mixing them on the same medium, particularly if it's intended >> for dissemination. If the platforms are disparate, you certainly don't need > >Ok, Mr. Wizard. Build a time machine, travel back in time, and urge all >the various computer manufacturers to never, NEVER mix their OS with the >rest of the program space on the disk. Fortunately, we are not trying to >revise the reality of our world, but are merely trying to deal with what >it has become, which is a much simpler procedure. Done! the OS was never mixed with data on CPM disks until CPM3 and CPM86. the system booted off OS specific tracks and DATA was never stored there and SYSTEM was never stored on DATA tracks. This applies to CP/M {1.3, 1.4, 2.0, 2.2} explicitly and many others as well. It makes little difference though. as then only reason is to make the boot easier as the booter then doesn't have to know the file system to read and launch the system which for cpm wasn't defined until boot completed (as the system tables were part of the boot image). Allison

26 years, 1 month

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Defining Disk Image Dump Standard

by pete＠dunnington.u-net.com

On May 31, 19:12, Tony Duell wrote: > In any case, for the <nth> thime, we are discussing archive format to be > used to store images of these floppies. Store them on something other > than floppies. Like hard disks, CD-ROMs, EPROMs (if you insist!), etc. Can I encode mine on knotted string? My mother has a box with an *awful* lot of string. Should I use the thicker string for DD disk archives? -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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VAX-11? and some C64 stuff

by mcguire＠neurotica.com

On May 31, Jason McBrien wrote: > First, there was the PDP/8 which came out in the sixties. It was a largish > "Minicomputer" meaning it didn't fill a room like the IBM 360's, but you > couldn't exactly toss it in a closet either. Then came the PDP/11, which was > a bit smaller and 16-Bit in the seventies. Then came the VAX 11/750, > Digital's first 32-Bit mainframe, in the late seventies/early eighties, and > dominated the minicomputer market for quite a while. The first VAXes where > large cabinet sized affairs, needing wacky 380V power mains and hard drives > the size of a decent size car transmission. Then came the VAXStation 2000, > which had almost all the power of a VAX 11/750 in a case the size of a > largish shoebox. The home minicomputer was born. Through the eighties DEC > still made the huge company-running VAX 7000's, 8000's, 9000's, and 10000's, > but also made smaller workstation-style counterparts, the VAX 3100's, > 4000's, MicroVAXes, VAXStations, and VAX-Servers. You can pick up a 3100 or > 2000 for under $50 if you look hard. 4000's are nicer and run upwards $100. A few corrections here...the 11/750 was the second VAX model, not the first. The first was the 11/780. The VS2000 was approximately the performance of the 11/780, not the 11/750. The 7000, 9000, 1000, etc (not 8000) were mostly 90's machines, not 80's, if memory serves...some of which are still available for new purchases from DEC/Compuke, though not for much longer. > You'll want to get a VAXStation, as opposed to a MicroVAX, cause it supports > a monitor, MicroVAX's are terminal controlled. Also, you'll need the special ...depends completely on the intended application. Myself, I have 28 machines on my home network. Only ONE of them, the one I sit in front of every day, has a big tube and a framebuffer. The other ones are in the computer room making noise and belching out heat...where they most certainly DO NOT need a big 19" monitor taking up space, or a never-used framebuffer sucking up power and kernel code space. A single VT320 terminal with a very long serial cable sits in the side of the room on top of an UPS. When I need actual console access to the machines (which is very rare, only during some reboots, which are in themselves very rare here) I string the serial cable to the console port of the machine in question and I'm set. In another week or so, a terminal server will be connected to all the console ports, as well as the VT320 terminal. Then I won't even need to be downstairs (or in the house at all) to gain console access. -Dave McGuire

26 years, 1 month

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OT: Archiving data (LONG)

by CLASSICCMP＠trailing-edge.com

>> Maybe photographic film quality "paper tape" is the answer. The other >> solution may be photographic film floppy disks. I'd better get right off to >> my patent attorney and file. >Mylar punched paper tape has a VERY long lifetime and is even human >readable (well sorta ;)). But not a particularly high density - 10 Bytes per square inch. I think mike was talking about storing data on photographic film, like many of the microfiche data storage systems already in use, but intended for direct computer reading. Many films will resolve 100 line pairs per millimeter; this directly translates to about 3.2 MBytes per square inch. This isn't particularly new technology, but it'll probably never become widely used in the consumer sector. Most end-consumers simply don't think even a couple of years ahead; witness all the folks who transferred home movies to videotape, which might last for a decade or two at most, and then tossed the original film. The original film would've been good for centuries if processed properly. -- Tim Shoppa Email: shoppa(a)trailing-edge.com Trailing Edge Technology WWW: http://www.trailing-edge.com/ 7328 Bradley Blvd Voice: 301-767-5917 Bethesda, MD, USA 20817 Fax: 301-767-5927

26 years, 1 month

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Defining Disk Image Dump Standard

by mgregory＠vantageresearch.com

-----Original Message----- From: Pete Turnbull <pete(a)dunnington.u-net.com> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Wednesday, May 31, 2000 5:14 PM Subject: Re: Defining Disk Image Dump Standard >On May 31, 19:12, Tony Duell wrote: > >> In any case, for the <nth> thime, we are discussing archive format to be >> used to store images of these floppies. Store them on something other >> than floppies. Like hard disks, CD-ROMs, EPROMs (if you insist!), etc. > >Can I encode mine on knotted string? My mother has a box with an *awful* >lot of string. Should I use the thicker string for DD disk archives? > If you want increase your data storage capacity, you could colour code the string, too. Everything old is new again ... we've just re-invented the Inca quipu, a few centuries on. Regards, Mark.

26 years, 1 month

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IBM I/O Selectric/Posting Machine (Was RE: Atari 800 keyboards)

by mrdos＠swbell.net

How much do you want for it, and where is it? It sounds neat. >God, the dynatyper, I remember that... > >On a related note, I have an old I/O Selectric, not the generalized >model, but one that appears to have been a teller terminal of some >kind. Perhaps it was even used by a vehicle license branch. > >Anyway, I never could get it to function with the IBM controller >that came with it (which I think put out EBCDIC), but it also came >with an aftermarket controller (which I think put out ASCII). > >If anyone has been searching high and low for one of these, I'd >probably let go of it for the right price or trade. > >Shipping will be a killer, tho; it's very heavy. > >-doug q > >

26 years, 1 month

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Finds

by mcguire＠neurotica.com

On May 31, Mike Ford wrote: > >A Sparcstation 10 -- Fantastic. Got to find something like that for > >Solaris 8. > > Will 8 run on a 10, my wife wants a home system to play with instead of the > E250 she has at the office, and told me she needs at least a 5 (which is a > much newer system than a 10 or 20 right?). Newer than a 10, about the same age as a 20 as I recall... -Dave McGuire

26 years, 1 month

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OT: Archiving data (LONG)

by pete＠dunnington.u-net.com

On May 31, 13:42, Sellam Ismail wrote: > On Wed, 31 May 2000 CLASSICCMP(a)trailing-edge.com wrote: > > > >Yes, but how long can we expect the film to last? > > > > Decades, if processed sloppily, or centuries, if processed archivally. > > > > The availability and maintainability of the readout systems becomes, IMHO, > > the deciding factor. If the data is stored as human-readable text this > > isn't so much a problem, until languages change or are forgotten at least. > > Sounds great, but how readily available is the process of film archiving > to hobbyists, how easy is it to master, and how much does it cost? > > Unless the answers, in order, are extremely, extremely, very little, then > keeping the archive on mirrored servers is still the best solution we > currently have. Well, for monochrome film, which is essentially what Tim was talking about, the answers *are* "extremely, extremely, very little". What it amounts to is using reasonably pure water for the three[1] main processing solutions, making sure the fixing process is properly completed (and uses proper fixer, not a "stabiliser"), and that the film is finally washed thoroughly. [1] Assuming an ordinary silver-based emulsion, developer, stop-bath, and fixer; gold and platinum emulsions also exist, and there are common simple techniques to replace the developed silver image with a dye (typically less robust than the silver, though) or to make it combine with something else. Usually that's done to alter the colour or the contrast though, and isn't applicable to "line" film. -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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VAX-11? and some C64 stuff

by pete＠dunnington.u-net.com

On May 31, 17:40, Dave McGuire wrote: > I mean, realistically...I'm ONE person, I sit in ONE chair at a > time, I drink from ONE can of Mountain Dew at a time...why do I need > more than one video system at a time? Because you need a second one for all that modern "documentation" that only comes in detestable online form :-) -- Pete Peter Turnbull Dept. of Computer Science University of York

26 years, 1 month

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OT: Archiving data (LONG)

by xds_sigma7＠hotmail.com

Hmm what about microfiche? And paper's storage lifetime is very dependant on where you are, that's why I love CO, its dry enough here that paper stays in great shape... Will J ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

26 years, 1 month

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A moment of silence...

by kyrrin＠bluefeathertech.com

A moment of silence, if you would, please, for the death of another long-lived electronics/computer surplus place. At the end of last month, Haltek Electronics, Mountain View, CA closed their doors. Not because they wanted to, nor because they didn't have a loyal following, but purely because of greed on the part of their jackass of a landlord. It seems that their lease was up for renewal. Their landlord, decided to get greedy, and wanted to at least double what they'd been paying for rent (maybe even 2.5 or triple... I'm not certain). In any case, they could not have continued to make a reasonable profit given what said landlord wanted to do, and there was no better location available. They opted for a quiet and dignified end. While they may rarely have had the best prices on test gear or computer hardware, Haltek was a very helpful source of parts for me and Lord only knows how many other electronics types in the Bay Area and beyond. I sincerely hope their landlord ends up holding on to a completely empty building for a VERY long time! Methinks he's a graduate of the Bill Gates School of Compassion. :-P Whatever else happens, I pray that other surplus stores, such as Weird Stuff and Sharon Industries, aren't next on the chopping block. -=-=-=-=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner/Head Honcho, Blue Feather Technologies (www.bluefeathertech.com) kyrrin(a)bluefeathertech.com "SCSI Users, Unite! Beware the IDEs of March!"

26 years, 1 month

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