test-drb

test-drb@ccmp.vtda.org

101090 discussions

by adavie＠mad.scientist.com

Pictures are worth 1000 words - my earlier text post didn't elicit any responses... maybe one of you can ID this board (or more particularly, the type of system) from the pictures. Two pics available; large and small. The connector shows the single "pin" on this side, and multiple separate pins on the reverse. http://www.comcen.com.au/~weird/boardbig.jpg [250K] http://www.comcen.com.au/~weird/boardsmall.jpg [95K] Betcha can't! A

28 years, 1 month

Bill a TRS-80 fan? (Was More List Operation Stuff)

by lisard＠zetnet.co.uk

On 1998-03-19 classiccmp(a)u.washington.edu said to lisard(a)zetnet.co.uk :Question: :Is Bill using a TRS-80 here? I think I see 64 cols per line :formatting, hmmmmmmmmmm........... or alternatively, he could have a block editor running under forth and be posting from there... ;> -- Communa (together) we remember... we'll see you falling you know soft spoken changes nothing to sing within her...

28 years, 1 month

Irreverence to irrelevance

by COAKLEY＠AC.GRIN.EDU

> > But the calculator collectors have their own lists, don't they? > > True... I'm not thinking of spamming this list with pocket calculator > questions or anything like that. I'd just not object to the odd thread on > them, particularly if they were historically significant (the HP9100...), > technically interesting, or whatever. Speaking of which, there's an HP41C at a thrift store near me. Anyone want it? Is it at all interesting? (Sorry, Allison. I thought my last message was going to the list, and not to you privately.) -- Ben Coakley http://www.math.grin.edu/~coakley coakley(a)ac.grin.edu Station Manager, KDIC 88.5 FM CBEL: Xavier OH Wow, this is global. -Mtn Goats

28 years, 1 month

Amiga A1060 SideCar

by ds_spenc＠alcor.concordia.ca

I finally got around to archiving what ROMs I could find in my old SideCar, and I have a few questions. I know the comp.sys.amiga.hardware would probably be a better place to ask, but I'm going to ask here anyway. :) [The SideCar, for those that don't know, is basically an XT clone that attaches to the side of an Amiga 1000, whos display normally appears in a window or on a separate 'screen' on the Amiga display.] I didn't completely disassemble the SideCar, I only took the cover off and poked around a little. I got my SideCar 'third-hand' and never had the manual for it. I never played with the dip switches or jumpers in it. Does anyone know what all the dip switches are for? There's a bank of eight of them, and another of four. Currently the 8 are: OFF, ON, ON, OFF, ON, OFF, OFF, ON. The set of 4 are all OFF. I checked through memory with DEBUG and located the BIOS code as well as the stuff the Amiga sends to the PC side via the dual-port RAM. I don't know how big the BIOS is supposed to be. It looks like it's in two chunks, of about 4K and 8K. The first section of this code lies at F4000 and goes to about F4Cxx, followed by a bunch of FF's, then at F6000 is a solid 8K chunk of code, including copyright messages from Commodore Electronics Ltd. and Phoenix Software Associates Ltd. Would all of this be in a 16K chunk in the EPROM at location U22 on the motherboard? It's a 48-pin EPROM with a sticker on it that reads "380619-02" and "Hydra BIOS 2.05". Under the daughterboard and the hard drive (I replaced the floppy drive with an ST-296N in 1991 or so) where I couldn't really see very well, were at least two other 48-pin chips, at U39 and U40. The only number I could see was "8621" on the one at position U40. I know that's not a lot of information, but does anyone know what those are? I'm just interested in how the SideCar performs its magic. I looked into the RAM area from E0000-F3FFF which is the shared RAM, and I was surprised to see some stuff in there from the Amiga side that I don't think should have been there. After the PC.boot file stuff that was loaded into the PC side by the Amiga at startup, there was the "info" program from the Amiga shell. Executing something else on the Amiga side cleared that area out, and executing "info" again (from ARP 1.3, not the real AmigaDOS) put the info code back in there. Also, some filenames from directories on the Amiga side showed up in there. What's going on? The SideCar controls the hard drive for the Amiga. Does the Amiga get the data from the HD through this memory area? I've never been able to get AREAD/AWRITE to function. They always GURU. I got the files from a BridgeBoard distribution... do I need special ones for the SideCar? Now, the main reason I actually opened the SideCar up: I installed a Seagate SL-02 SCSI controller when I installed the hard drive. It conflicted with the floppy controller in the SideCar, and in order to have floppies and hard drive running at the same time, I had to disable the floppy controller on the SCSI card. I did this by putting masking tape over each pin on the card in turn, booting up the Amiga and the PC side, and recording the results. I eventually decided, from these results, to tape over 7 of the pins on the SCSI controller card, and this has worked perfectly since. I don't know how the pins are numbered, but below is an ASCII graphic representation. :) The 5th, 6th, 10th, 18th, 19th, 22nd, and 26th pins are taped over, on the left hand side of the card, reading from front to back. xx x xx x x | ===============================| |o I hadn't recorded this anywhere, and I was a bit worried that the tape would be drying out and falling off and making my SideCar go crazy, but everything was OK. And now it's recorded somewhere. :) Oh, one other thing. The first part of the boot message is as follows: Commodore Hydra BIOS Rev. 2.05 - Test Release - Copyright (C) 1985 by Commodore Electronics Ltd. Copyright (C) 1984,1985 by Phoenix Software Associates Ltd. All Rights Reserved. The serial number is under 1000. I'm wondering how common the A1060 SideCar is, and if anyone has one that doesn't boot up with the "Test Release" message. The motherboard says: FAB 380517-01 Rev.4 ASSY NO. 380604-01 Rev.7 ?1986 COMMODORE SIDECAR MAINBOARD Are there earlier or later revisions out there? Doug Spence ds_spenc(a)alcor.concordia.ca

28 years, 1 month

Now: Once again, whattheheckisa computer? (Was: Re: Delay lines)

by zmerch＠northernway.net

;-) Clearing the snow from my glasses, I saw Doug Yowza typed: >On Sat, 21 Mar 1998, Roger Merchberger wrote: > >> The absolute definition of a computer as I remember >> it goes thusly: >> >> "An instrument which can perform arithmatic and logical functions without >> the aid of a human." > >That's too ambiguous to me. All computers require the aid of a human at >some point. What's the diff if I pay Bill Gates to program mine or if I >work the slides on my slide rule? The difference is: there's no enter key on a slide rule. You can enter a program into a computer, and once it begins executing it may not require human interference until it has completed. If said program includes both arithmatic and logical functions between the pressing of the enter key and the output, it would fit the definition of a computer. >As for me, whenever I see little chicklet keys on a calculator, that's >enough for me to say it's not a computer :-) Ah, then you have an anti-Tandy bent, eh? For the chicklet keys on my CoCo1's preclude it from your definition??? ;-) (And, to continue along this nasty bend in the road, the membrane-only keyboards of the Timex Sinclair 1000 and Tandy's MC-10 make them akin to a microwave oven? ;-) I guess I see a lot more computers than you do! Just my $0.02USD ($0.026CDN), "Merch" -- Roger Merchberger | If at first you don't succeed, Owner, MerchWare | nuclear warhead disarmament should zmerch(a)northernway.net | *not* be your first career choice.

28 years, 1 month

Freedom!

by ds_spenc＠alcor.concordia.ca

Ahhh, finally I had a day that was free enough of other obligations that I could sit down and tinker with some of my old toys. The machines I played with today: Amiga 1000 with SideCar, Tandy 1000EX, Atari 800XL, Kaypro II and 2, TeleVideo TPC-I, 'A.M.A. LCD Portable' (286 luggable with LCD screen). I also had time to inspect a few pieces of junk I don't know anything about, that had been collecting dust on shelves. Anyway, it's great to have time to relax and tinker and post. I'll put specific comments and queries in appropriately titled messages. Doug Spence ds_spenc(a)alcor.concordia.ca

28 years, 1 month

Delay lines

by engine＠chac.org

At 01:21 3/21/98 -0600, Doug wrote: >Has anybody ventured a definition of computer that allows us to weed out >mere calculators? How about: > >* must be programmable >* must be general purpose >* must have alphanumeric input capabilites >* must have alphanumeric display capabilites You can even throw in "must have stored-program memory" and, bingo, an HP9100 is a computer. __________________________________________ Kip Crosby engine(a)chac.org http://www.chac.org/index.html Computer History Association of California

28 years, 1 month

Now: Once again, whattheheckisa computer? (Was: Re: Delay lines)

by zmerch＠northernway.net

;-) Clearing the snow from my glasses, I saw Doug Yowza typed: >On Sat, 21 Mar 1998, Roger Merchberger wrote: > >> The absolute definition of a computer as I remember >> it goes thusly: >> >> "An instrument which can perform arithmatic and logical functions without >> the aid of a human." > >That's too ambiguous to me. All computers require the aid of a human at >some point. What's the diff if I pay Bill Gates to program mine or if I >work the slides on my slide rule? The difference is: there's no enter key on a slide rule. You can enter a program into a computer, and once it begins executing it may not require human interference until it has completed. If said program includes both arithmetic and logical functions between the pressing of the enter key and the output, it would fit the definition of a computer. >As for me, whenever I see little chicklet keys on a calculator, that's >enough for me to say it's not a computer :-) Ah, then you have an anti-Tandy bent, he? For the chicklet keys on my CoCo1's preclude it from your definition??? ;-) (And, to continue along this nasty bend in the road, the membrane-only keyboards of the Timex Sinclair 1000 and Tandy's MC-10 make them akin to a microwave oven? ;-) I guess I see a lot more computers than you do! Just my $0.02USD ($0.026CDN), "Merch" -- Roger Merchberger | If at first you don't succeed, Owner, MerchWare | nuclear warhead disarmament should zmerch(a)northernway.net | *not* be your first career choice.

28 years, 1 month

Delay lines

by jredin＠earthlink.net

Dear friends, I love computers indeed, but behind calculators are almost 400 years of history, so there is a lot of very interesting material to learn and research. Regards, James Redin http://www.dotpoint.com/xnumber The X-Number World of Calculators ---------- > From: Doug Yowza <yowza(a)yowza.com> > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: Re: Delay lines > Date: Friday, March 20, 1998 11:21 PM > > On Fri, 20 Mar 1998, Kip Crosby wrote: > > > >> But the calculator collectors have their own lists, don't they? > > > > > >True... I'd just not object to the odd thread on [calculators] > > >particularly if they were historically significant (the HP9100...), > > >technically interesting, or whatever. > > > > Hear, hear! Especially since many so-called calculators were built by > > manufacturers not, for whatever reason, prepared to admit they were > > building computers -- with IBM and HP springing to mind at once. > > I know people collect calculators, but I just can't imagine how it can > bring the same kind of satisfaction as computer collecting. You can't > really hack a calculator. They don't lend themselves very well to > restoration efforts. They can't do many tricks. And few of them have any > sort of personality (OK, I'll admit that HP tries pretty hard in this > area). > > Has anybody ventured a definition of computer that allows us to weed out > mere calculators? How about: > > * must be programmable > * must be general purpose > * must have alphanumeric input capabilites > * must have alphanumeric display capabilites > > Unfortunately, this would mean that an Altair isn't a computer until you > add a terminal, but it keeps those pesky HP-65's out of the group. > > -- Doug >

28 years, 1 month

Now: Once again, whattheheckisa computer? (Was: Re: Delay lines)

by zmerch＠northernway.net

;-) Clearing the snow from my glasses, I saw Doug Yowza typed: >I know people collect calculators, but I just can't imagine how it can >bring the same kind of satisfaction as computer collecting. You can't >really hack a calculator. They don't lend themselves very well to >restoration efforts. They can't do many tricks. And few of them have any >sort of personality (OK, I'll admit that HP tries pretty hard in this >area). Uh, and what about that "grey area" of programmable calcs? Not only do they have personality... 1) my trusty Casio programmable calc of 12 years ago that started me thru college, may it R.I.P. is wholly program code compatible with my new(er) 9700 (icon-based screen, 32K RAM)... 2) The TI-59 had not only magnetic card storage, but also a ROM-card library, (at least) one of which was a ROM of games... including an interesting football simulation. but in most (if not all) definitions of a computer, they fit. >Has anybody ventured a definition of computer that allows us to weed out >mere calculators? How about: Why? As you seem to be less interested in calcs, it seems many on this list may be as interested, and if they do fit the definition of a computer, why can't they be included? The absolute definition of a computer as I remember it goes thusly: "An instrument which can perform arithmatic and logical functions without the aid of a human." Which to me would: exclude sliderules (tho the thread on here I found *very* interesting and enjoyed), include mechanical / analog computers, (to me) exclude basic / 4-function calcs (some folks think carrying & single-memory storage encompass logical functions... I disagree) include programmable calcs... (heavens, my Casio calc has more memory than my Tandy 200... Goodness!) Granted, these points are primarily moot, for the definition of a computer as to be used on this list would need to be defined by Mr. Bill Whitson, the (still) owner of this list. >* must be programmable >* must be general purpose >* must have alphanumeric input capabilites >* must have alphanumeric display capabilites My New Casio fits all these descriptions (but is not 10 years old), my old Casio fits all and is old too, and (with a slight stretch for input) so does my TI-59. >Unfortunately, this would mean that an Altair isn't a computer until you >add a terminal, but it keeps those pesky HP-65's out of the group. By your definition, adding a terminal to an altair would not turn it into a computer... for the computer is only performing I/O on an RS-232. The terminal is doing the displaying. To fit your definition, you would need to add a dedicated keyboard & video board to said Altair... So, you've successfully excluded Altairs, but included Casio calculators... Or is this just an HP vendetta???? :-) Just my (awkward) views... Roger "Merch" Merchberger -- Roger Merchberger | If at first you don't succeed, Owner, MerchWare | nuclear warhead disarmament should zmerch(a)northernway.net | *not* be your first career choice.

28 years, 1 month

oddball find PS/2-50

by allisonp＠world.std.com

Because they are sufficiently off the path of my interests I may trade both of them off. They look pretty neat but, I have no spares and they can serve as spares for the rest of my systems. That and I'm not really into collecting PCs. Allison

28 years, 1 month

Delay lines

by allisonp＠world.std.com

<Exactly. In the particular case of the Friden it was called a supersonic <delay line, although I've never been sure why. acoustic delay lines, they propagate bits translated to mechanical impulses at the speed of sound in a solid. The resulting delay is long enough to use ans a shift register to store bits. Allison

28 years, 1 month

information

by pete＠dunnington.u-net.com

> Videotext never really caught on in the US except on cable TV as a > non-interactive display. I believe there are still a few videotext services > piggybacking on satellite channels. They transmit on one of the unused scan > lines at the top of the picture, similar to closed captioning for the deaf. > > To my knowledge the only truly successful videotext implementation > was the french minitel telephone directory. data piggy-backed on TV signals, using several lines in the blanking interval, is called viewdata. data presented in the same screen format as viewdata, but interactively, over a phone line, is called videotext. Collectively, videotex = videotext + viewdata. The original standards were for 25 lines of 40 columns, in 8 colours. Characters can have attributes like "flashing" or "hidden" (for quizzes), and there are rudimentary graphics using a 2x6 mosaic pattern in each character cell. There are several not-quite-compatible viewdata standards, some of which offer much higher resolution and colour range (the German Bilschirmtext system BTX does this). AFAIK, all the videotext systesm, at least in Europe, are the same, and the BBC and UK independent TV companies all use it for news, programme listings, etc, as do a lot of the european satellite TV channels. UK's PRESTEL, Germany's BTX, France's Minitel, all use slightly different forms. Lots of UK travel agents use a private PRESTEL-compatible system, and at least a couple of banks and building societies here use the same standard for home banking. A few UK bulletin boards used to use the same format, and I think one or two still do, for nostalgic reasons. You can get two or three host systems to run on machines like BBC Micros. There's a web page somewhere devoted to this old stuff, but I can't remember the URL (if anyone really wants it, I'll look). There are BTX and Minitel emulators for X-windows, and I have a PRESTEL terminal emulator package for X-windows (works well but still needs a bit of tidying up) which AFAIK is the only free PRESTEL-compatible one for unix systems. -- Pete Peter Turnbull Dept. of Computer Science University of York

28 years, 1 month

Northstar S100 compatability

by allisonp＠world.std.com

<Now I'm going to consider voltage wrt the machine ground i.e. the bottom <of the transformer winding, not the tap. Also on NS* there is an option to not make the metal chassis DC grond to the logic. So ground must be the backplane ground. I suspect Tony has a possible solution, miswiring of the secondary. <I don't know where you are in the UK (can I conclude from your machine <name that you are near Peterborough?), but if you think I can be of any <help, please e-mail me. I have some generic S100 docs (although nothing <N* specific - if you get anything, I'd be interested in seeing it), and a I have a full set of NS* docs but I happen to be on the wrong side of the pond. The PS schematic is pretty trivial. Tony had the design of the +/- 16v correct. If you open the power supply up to see the transformer leads 2,3 and 6 are conneted to ground and common. For the +/-16 leads 5 and 7 go to the bridge rectifier. For the +8 leads 1 and 4 go to the really big diodes mounted on the L-shaped bracket. The 8900uf cap should have -16 to -22v across it and the 11000uf cap +16 to 22v. The largest 180,000uf cap should have +8-10v. Allison

28 years, 1 month

Time/Date stamper

by SUPRDAVE＠aol.com

I remember hearing a trick about soaking a printer ribbon with WD-40 to revive it. YMMV of course. david In a message dated 98-03-20 20:03:00 EST, you write: << I recently picked up a time/date stamper from the trash. It is a box with a slot, and when a paper is inserted, the paper is stamped. The first year on the stamping drum is 1951, so I assume that's when it was made. It uses a cloth ribbon for ink. How do I reink it? Also, the stamping has impressed the numbers into the rubber platen. How do I get rid of that? >>

28 years, 1 month

Heinz Nixdorf

by jredin＠earthlink.net

Dear friends, I'm recollecting information for an article I will write about the transition of electro-mechanical calculators to electronic calculators during the 60's. I've found that the ANITA from Sumlock Comptometer of England (1963) is usually regarded as the first electronic calculator [1]. However, recently I found an article about Heinz Nixdorf of Germany in the LEXICON's History of Computing (CD-ROM) which indicates that he built several models of electronic calculators back in 1954 (Models ES12 and ES24). I haven't been able to obtain more information on these calculators. I suppose this is because Nixdorf moved soon onto the computers technology (eventually joining with Siemens). As a reference, I posted a copy of the Nixdorf article in my web site at the following address: http://www.dotpoint.com/xnumber/chistory.htm Information about the Anita can be found at: http://www.dotpoint.com/xnumber SECTION: VINTAGE CALCULATORS --> ELECTRONIC --> ALBUM --> Anita Any information on this subject will be appreciated. Regards, James Redin ----------------------- [1] Bruce Flamm, "The World's First Electronic Calculator - Who Made It?" The International Calculator Collector - Fall 1996, Issue #14.

28 years, 1 month

Time/Date stamper

by maxeskin＠hotmail.com

I recently picked up a time/date stamper from the trash. It is a box with a slot, and when a paper is inserted, the paper is stamped. The first year on the stamping drum is 1951, so I assume that's when it was made. It uses a cloth ribbon for ink. How do I reink it? Also, the stamping has impressed the numbers into the rubber platen. How do I get rid of that? ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

28 years, 1 month

Apple - PC

by allisonp＠world.std.com

<the trackstar was made years ago in the late 1980s. in fact, radio shack <to have it in the catalog for sale! you might want to check out ebay.com <they did have some of these cards for ~$20 about two months ago. it's a f <length isa card that you plug a standard disk ][ into. dont know about vi <though. supposedly they were quite compatible and one could run just abou <anything on that card. I have one of these. A Diamond Trackstar 128k, has two 65c02s and 128k of ram. It can use the standard 360k drives and the apple ones as well. What I don't have for it is the software. Looks really neat and useful. I don't know if it would work in anything later than an XTclass machine and without software it's hard to determine that. Allison

28 years, 1 month

Northstar S100 compatability

by allisonp＠world.std.com

<Now that's where an IMSAI front panel really paid off. You put <in the card, stored an FF in the first location, the panel <display show EF instead...bingo, the RAM on D4 is bad (or more <likely a bent pin or upside down in socket). Or run NSdos and use the ramtest program. Another solution is load a monitor into known memory and fill ram with 00 or ffh to detect stuck bits. Allison

28 years, 1 month

OK, Time to make an attempt at ending this...

by jfoust＠threedee.com

"Daniel A. Seagraves" <DSEAGRAV(a)toad.xkl.com> wrote: >BTW, That's *NOT* a mail bomb. He asked for it. I've been ^Qing thru all >that crap all morning, and I'm sick of it. He wasted a lot of my time, so >I'll waste a few of his. Besides, it's only about... *clicky click* 39 meg. Daniel, mail bombs, real or implied, are a childish act. They accomplish nothing except annoyance and can cause loss of other important mail by any user on the involved systems. It's as effective as insulting your computer when your program has a bug. I thought the public posting of private messages was quite egregious, too, but Daniel didn't do that. - John Jefferson Computer Museum <http://www.threedee.com/jcm>

28 years, 1 month

Northstar S100 compatability

by allisonp＠world.std.com

<From: Simon Coombs <simon(a)nenevr.demon.co.uk> <Subject: Northstar S100 compatability <Does anyone have any idea what sort of RAM cards the Horizon likes to <play with? My system already has an (albeit flakey) RAM-16 card, and I <have the remains of an old Godbout Econoram-II card, sans about half its <chips. I have *no* idea whether this card was ever used with the N*. Ram16 or ram17, any 8k/16k/64k static ram cards all work and may of the dynmaic ram cards that have local (on card refresh). The NS* was pretty clean so most memory bords worked well. The econoram-11 and the ram16 both work. The ram16 should be easy to fix it's static and uses 2kx8 parts. <retired gracefully. I think that the PSU could do with some adjustment, <too; if anyone in the UK has schematics for any of these bits, and would Northstar* PSU requires adjustment???? The Horizon used three terminal FIXED REGULATORS. Unless you mean 120v/240v wiring of the mains transformer. Allison

28 years, 1 month

Videotext

by chemif＠mbox.queen.it

At 07:43 21/03/98 +1100, you wrote: >When I talked to the designer of the Mattel videotext system, I was confused >and mentiioned this piggybacking on TV signals in the blank area, and he was >kinda amused that I would confuse videotext with TELEtext. Videotext had >dedicated phone numbers your system would ring up. Teletext was piggybacked >on TV signals. Yes, they are two different services. Here in Italy the Videotext service is called "VIDEOTEL" and works using the Teletel/Prestel standard with speed 75/1200 baud. The Teletext service broadcasted from RAI is called "TELEVIDEO":the signal is inserted in the TV frames and can be seen with a decoder. The informations are divided in pages (capacity abt. 990 per TV channel) regarding many topics: from weather forecasts to news, tv programs schedule, and other info that can be recalled with the remote control. Some broadcasters uses it as an economic "one way" data transmission (Telesoftware). With a special pc-board connected directly with the TV antenna, is possible to download files transmitted as multiple pages (E.G. the price updates for the the pharmacies). Ciao ???????????????????????????????????????????????????????????????????????????? ? Riccardo Romagnoli,collector of:CLASSIC COMPUTERS,TELETYPE UNITS,PHONE ? ? AND PHONECARDS I-47100 Forli'/Emilia-Romagna/Food Valley/ITALY ? ? Pager:DTMF PHONES=+39/16888(hear msg.and BEEP then 5130274*YOUR TEL.No.* ? ? where*=asterisk key | help visit http://www.tim.it/tldrin_eg/tlde03.html ? ? e-mail=chemif(a)mbox.queen.it ? ????????????????????????????????????????????????????????????????????????????

28 years, 1 month

Videotext

by adavie＠mad.scientist.com

28 years, 1 month

information

by adavie＠mad.scientist.com

OK, I'm lucky enough to have prototypes of a videotext system using the Mattel Aquarius computer. I have hardware, and more importantly software, manuals, and some videotext specs. I've got the things the guys used to design their hardware - that is, the low level detail. I also have some 25 year old printouts of videotext screens. Rather neat. Contact me if you want copies, basically at cost - or I will dig out particular information gratis. Cheers A -----Original Message----- From: Jack Peacock <peacock(a)simconv.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, March 21, 1998 5:20 AM Subject: Re: information Turlough O'Brien wrote: "videotext" but there is little to no information available on the net about "Videotext" or in the libraries.I would greatly appreciate it if you could send me some informatin on the subject. (This is from memory and unreliable) There was a proposed standard for North America called NAPLPS, for videotext presentation. I believe it was sponsored by Philips. If someone has a complete collection of BYTE magazines, I recall there was an issue devoted to videotext, circa 1981. The one clever feature of NAPLPS was that the graphics were based on floating point coordinates. Because screen sizes and resolutions would vary, positioning and sizing graphics was a problem. NAPLPS used a coordinate system where the width and height of the screen ranged from 0 to 1. For instance, to place a pixel in the center, you referenced coordinates (0.5, 0.5). Videotext never really caught on in the US except on cable TV as a non-interactive display. I believe there are still a few videotext services piggybacking on satellite channels. They transmit on one of the unused scan lines at the top of the picture, similar to closed captioning for the deaf. To my knowledge the only truly successful videotext implementation was the french minitel telephone directory. Hope this gives you a place to start. Jack Peacock

28 years, 1 month

PDP parts wanted (cross post)

by rhblake＠bbtel.com

This plea for PDP items was on the "Obsolete Computer Helpline" today and form the traffic lately I'm sure someone could contact this person to give him some pointers by direct email. >Steve Hogan <SHogan7080(a)aol.com> >Nottingham, UK - Friday, March 20, 1998 at 03:27:29 > > HELP > > I am looking for a source of spares for Digital PDP 11 computers. > > In particular, and Disk Controller and Disk Formatter cards -------------------------------------------------------------------- Russ Blakeman RB Custom Services / Rt. 1 Box 62E / Harned, KY USA 40144 Phone: (502) 756-1749 / Data/Fax:(502) 756-6991 Email: rhblake(a)bbtel.com or rhblake(a)bigfoot.com Website: http://members.tripod.com/~RHBLAKE/ * Parts/Service/Upgrades and more for MOST Computers* --------------------------------------------------------------------

28 years, 1 month

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test-drb