test-drb June 2000

test-drb@ccmp.vtda.org

160 participants
580 discussions

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

23 years, 11 months

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

23 years, 11 months

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

23 years, 11 months

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

23 years, 11 months

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

23 years, 11 months

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

23 years, 11 months

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

23 years, 11 months

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

23 years, 11 months

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

23 years, 11 months

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.

23 years, 11 months

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test-drb June 2000