test-drb August 1999

test-drb@ccmp.vtda.org

161 participants
565 discussions

by fpp＠concentric.net

Ok, heard back from my friend Bob the Epson man. he says"Epson never said that they made the first laptop computer. Epson said they made the first NOTEBOOK computer. This may seem to be a Marketing word game, but I feel that given that the computer was the first portable computer about the size of a notebook, their statement is true and is one of the few things they told us that was true. "

25 years, 4 months

imsai 2

by allisonp＠world.std.com

<transformer/rectifiers. So if you're going to have on-board linear <regulators anyway, there's little to be gained in efficiency by using an <SMPSU rather than a simple transformer/rectifier/cap supply. And the <latter is a lot simpler. Actually that's not true. having done it using DEC H74x power bricks on one system to regulate the +9.4V(@18A load) to 14V(unloaded) to +8. The reduction in onboard regulator heating was enough to make me investigate a simpler way. I ended up using SCRs and much cruder regulator (still switchmode) to narrow the wild swing to 8.5 to 9.3V over a 1-18A load swing. <I agree that if you were going to make a 8080/Z80 machine _now_ you'd not <copy the Altair or the Imsai. And you'd not use the S100 bus, most <likely. But that's not what they're trying to do here. Actually My comments were narrowly aimed. the IMSAI was a far better example of S100 and worth copying. Only ONE change I'd do... NO MAINS POWER ON THE FP! Back when I'd seen one altair and a IMSAI fried by someone comming in contact with that. It had no business there. <Oh come on. If you can't design a linear PSU, you probably can't design <the rest of the computer... And you test on dummy load (for considerable <periods). Linear is much easier than switchmode. Especially HV switch mode! <In any case, in an S100 system, the regulators are on the cards. If you <get the raw supplies slightly too high you're not going to damage <anything. And of course you test them before inserting any cards. True, but a common problem in S100 is excess heat, removing it and hte regulators if over dissapating shutting down (undesired due to when they might!). Simple switch mode and CVTs were a good solution as the regulation reqirements of 10-15% were acceptable for bus raw power. The solution used by some and I hold the TI peripheral bus (also used local on card regulation) was to use higher voltages, smaller caps to beat the effects of ripple. Again another bix that really needs the PS tamed down. Allison

25 years, 4 months

DC300 Tape Repair

by wsmith＠gj.com

>>> Tony Duell <ard(a)p850ug1.demon.co.uk> 08/18 10:57 AM >>> >> Yes. I have four original IBM 5100 data tapes (1 diagnostic and 3 BASIC >> Aided Instruction) all of which have broken belts. Age has taken its >> toll. I do have numerous other tapes, although only a few blank IBM's. >> The problem doesn't appear to affect the Scotch tapes, which is what I >> have most of. >In my (limited) experience you can't interchange parts (belts, idlers, >etc) between different makes of cartridge. So I guess you're going to >have to take some of the good IBM ones apart to repair the defective ones. >You could try using parts of the 3M tapes, but I doubt if they will work. The winding pattern is the same, but the belts are a different color. On the IBMs they are an off-white. On the Scotch they are brown. I also have several 3Ms where they are closer to black. With so many broken IBM belts I am reluctant to swap out what are likely to ultimately be more broken belts. ! ! !

25 years, 4 months

HP1000 ?????

by jlwest＠tseinc.com

A few weeks back someone on the list posted that they knew where some equipment was that was scheduled to be pitched. In addition to other gear, one of the items was an HP1000 system. I had expressed interest in the system, but have not heard anything for a while; I also can't find the email address of who it was. If you're on the list, please email me privately to discuss. Regards! Jay West

25 years, 4 months

DC300 Tape Repair

by wsmith＠gj.com

>>> Christian Fandt <cfandt(a)netsync.net> 08/18 5:37 AM >>> >>Yes. I have four original IBM 5100 data tapes (1 diagnostic and 3 BASIC >>Aided Instruction) all of which have broken belts. Age has taken its toll. >Oooh, ouch! Bet those tapes are hard to find (!). Definitely worth trying >to fix at least the diag tape. I have an extra diag. tape, but I haven't run it in a while. The first thing I'll do is copy it. >Hmmm, wonder if it would be practical to take a very good condition 3M >cart, dismantle it to bits and take the media from the defective IBM cart >and install it into the 3M cart. Of course, the spools will be different so >the media would have to be unwound from the old and wound onto the new. It >would take a _long_ period of time and a whole heap o' patience to do this >but it's a thought that came to mind. (I'm figuring the mechanical diffs >between the two sets of small parts would not allow simply installing a 3M >belt into the IBM cart.) I think I'd have to take the belt off to do this in any case, so it probably makes more sense just to replace the belt. Thanks, Wayne. ! ! !

25 years, 4 months

semantics (was Article on old software programs (for IBM, Apple, Borland, etc))

by edick＠idcomm.com

Just to add grist for the mill, I'd point out that people now are, perhaps erroneously, calling recorded program material for your stereo and your TV 'software' as well. Now, I would call a CD or a CDROM firmware, since you can't really change it, but who's splitting hairs . . . Years ago, people predicted that it would become increasingly difficult to distinguish hardware from software, though I doubt that. After all, if you can see it or touch it, it's hardware, right? Now we have software for building hardware. Not just the HDL's of various sorts, but one can actually realize a series of 'C' statements via VHDL or Verilog, among others, I'm sure, in a hardware (?) implementation. If we call the content of ROM and PROM devices firmware, it's reasonable to call the content of PAL and CPLD devices firmware as well, isn't it? What about the content of those volatile FPGA devices? They're not like PROMs, in that they forget what they learned last time power was on. They can be changed pretty readily. Some are even capable of running (yecchh!) self-modifying code <shudder> internally. What do we call all this "stuff" now? Dick -----Original Message----- From: John Ruschmeyer <jruschme(a)hiway1.exit109.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Wednesday, August 18, 1999 12:34 PM Subject: Re: Article on old software programs (for IBM, Apple, Borland, etc) >> > Bill, would you not call this an example of a hardware program? >> >> "Software" implies "program". "Software" by itself is sufficient. >> "Computer program" to differentiate from say "television program" >> I can accept because "program" by itself is ambiguous. I can accept >> "hardware program" as well, although I would say "programmed in hardware". >> If you said that that computer had "hardware software" I would have >> to kill you ;-) > >I'm not sure you can really say that "computer program" is any less >ambiguous than "television program", at least when taken with no >context. > >For example, Bill asks his friend, "Have you seen the new computer program?" > >Is he referring to: > > a. Front Page 2000 (a software application) > b. "The Computer Chronicles" (a television program about > computers) > c. A new political initiative aimed at puttimg more computers > in schools. > >Gotta love English... > ><<<John>>>

25 years, 4 months

At least SOMETHING went right today... New toy.

by DSEAGRAV＠toad.xkl.com

This SHOULD be on-topic, it DOES have a computer in it... Remember that Bell box I mentioned awhile ago? It turns out it's a Bell Dimension 400 PBX, and it's now mine. I got the console and boot tapes, and a mess of documentation. Some of it was inside the box, which wasn't too heavy (I was able to move it around (Up 5 floors! Cargo elevators are a good thing!) by myself, it's on casters.) The only bad things so far is the general state of disrepair of the unit - Some of the cards inside were dismounted, the modem inside had broken free and was boucing around, Also, the ceiling above it was crumbling, and so there's a bunch of white powder all over the top. From looking inside the front door though, it doesn't appear to have gotten inside. Oh, and the power plug is that odd round thing on PDP-11 power supplies, so I'll have to open it up and replace that. That shouldn't be TOO hard, unless I do something silly again, I really don't like playing around where line current is involved... So anyway, the usual 30 questions bit: 1. So, what can I do with this besides take up space? Can I plug this into the phone network? I plan on toting it to work and putting it to use there, where a PBX is desperately needed... Otherwise, I guess I could run it non-connected, but it'd be a waste. 2. Is this hard to program? I haven't had time to read thru all the manuals yet. I got 7 different manuals: A. Dimension 400 PBX task lists and index B. How to operate the Dimension attendant console (etc.) C. A small flip-type card listing all the feature codes... D. Dimension 400 PBX detailed level procedures. (500-659) E. Dimension 400 PBX detailed level procedures. (660-793) F. Customer order document. (I dunno what this is...) G. Schematic Drawings. (Don't worry, it's only block diagrams and general stuff, nothing really specific that I can see.) 3. Can I plug normal phones into this, or does it need special phones? I guess that's it. I'll learn a little more about it tomorrow when I fire it up... -------

25 years, 4 months

Wanted: jumper settings for Teac FD-235HF-101

by ethan_dicks＠yahoo.com

I have been over the numerous PDF files on the Teac web site. The *-101 drive is not listed. It has a row of jumpers near the power connector with some recognizable names (D0, D1, FG, H-HI...) and at least one with a mysterous name (OP). The problem that I am having is that I have this flat-panel PC with an external DB-25 for an external floppy. I have traced out individual pins from an internal 34-pin header to the DB-25, but have come up with several that don't connect... 34-pin: 2, 4, 6, 12, 16 AFAIK, pin 16 on a standard floppy is the MOTOR ON signal. The behavior is this: the drive seeks on boot, the disk auto-rotates on insertion and when it gets to the part of the initialization where the floppy is read, the LED lights up, the heads twitch, but the disk does not rotate. On 5.25" drives (i.e., FD-55GFR and pals), there are straps to control when to light the LED and when to fire up the motor. I cannot figure out if there is a way to tell this floppy to spin based on other signals than MOTOR ON. There are several "S*" jumper pads on the drive PCB. I did have to change one jumper before using this drive in a standard enclosure (it came from a four-disk floppy duplicator) in order to select it. It works find in a PeeCee now. I'd love to know what the half-a-dozen pads are for. Caveat: I don't mind swapping this drive out with another one, but I only have a source of +5V, not +12V from this connector (no, the FD-235 does not use +12V for the motor). -ethan === Infinet has been sold. The domain is going away. Please send all replies to erd(a)iname.com _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com

25 years, 4 months

DC300 Tape Repair

by wsmith＠gj.com

>>> Christian Fandt <cfandt(a)netsync.net> 08/17 5:42 PM >>> >Do I assume correctly you have an only copy of a very important OS tape or >something just as critical you're unfortunately trying to repair? Yes. I have four original IBM 5100 data tapes (1 diagnostic and 3 BASIC Aided Instruction) all of which have broken belts. Age has taken its toll. I do have numerous other tapes, although only a few blank IBM's. The problem doesn't appear to affect the Scotch tapes, which is what I have most of. Thanks.

25 years, 4 months

imsai 2

by CLASSICCMP＠trailing-edge.com

>What puzzles me is why the IMSAI folks decided to use a switching power >supply when the box and everything else already supported the needs of the >S-100 with the previously available and now quite inexpensive unregulated >supplies of yesteryear. Probably an issue of economy, using PC-clone power supplies at about $25 each vs using a custom-wound transformer at $200 or so a pop. > One of the main benefits of the S-100 was that it >had on-board regulation, so that if you didn't need a given supply, you >didn't have to bring it on board and regulate it, dissipating power as you >went. If the new box is capable of running the original boards, it must >provide the raw 8 and +/- 16-volt supplies. Where's the benefit in having a >switching regulator sitting in the back of the box? I suppose it creates a >market for a power distribution module to put +5 and +/- 12 on each board >which needs it rather than using the on-board regulators, but that opens >another can of worms. What's the "right" way to distribute it without >tampering with a historically correct board? According to what I read from the web page, there's a PC-clone switching power supply followed by a "boost" switching circuit to get back to +8 and +/- 16. That's not completely unreasonable, but it sounds a little bit fishy to me in the sketchiness of the details. Several S-100 manufacturers who were still at it in the mid-80's had regulated +5V on the S-100 backplane. Those who wanted to use their older S-100 cards in such a machine just jumpered across the 7805's and viola! -- 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

25 years, 4 months

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test-drb August 1999