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101090 discussions

by adavie＠mad.scientist.com

Re: BBC repair Oh, forgot to mention I have this interesting gold thingy. It fell out of the BBC when i opened it. To be more precise, it was wedged between a couple of chips, which I guess were RAm. top right near the video connector. It's about half an inch long, looks like it wrapped around the end of a wire. Hollow, one end looks like it can be crimped (its split in half). THe other end shaped like the mouthpiece of a wooden flute/recorder. I have an image up. http://www.comcen.com.au/~adavie/bbc.jpg What is this and do I really really need it? A

28 years, 4 months

Modern Minimalism (Was: Future Computing Trends)

by sinasohn＠ricochet.net

>QNX is a very small micro-kernel OS that has the look of Windows 95, has >builtin TCP/IP networking, a notepad, a few other little doodads, and to >top it off, a fully functional HTML 3.2 compliant web browser. Also Okay, QNX sounds pretty cool, but I hafta throw my vote in for Arachne. Graphical DOS web browser runs on anything, I think, and works great. I found it when I was looking for something to preview my web pages in (I do 'em in a DOS Editor). --------------------------------------------------------------------- O- Uncle Roger "There is pleasure pure in being mad roger(a)sinasohn.com that none but madmen know." Roger Louis Sinasohn & Associates San Francisco, California http://www.sinasohn.com/

28 years, 4 months

DataNumerics DL8 more info...

by adavie＠mad.scientist.com

When I get it, I will :) >Has anyone actually opened up this Datanumericls DL8A to see if it has >a S-100 bus, power supply, etc?

28 years, 4 months

BBC Model B - video help

by adavie＠mad.scientist.com

>Firstly, does Mode 7 behave correctly? Not only does it have the simplest >mapping, it also uses different address buffers between the 6845 CRTC >chip and the RAM. On my diagram, IC10 and IC11 are used in Mode7. IC8 >and IC9 are used in all the other modes. So if _all_ modes, including >Mode7 are faulty, then it's unlikely to be a buffer problem. Mode 7 behaves as my earlier email. Basic repeat unit 64. Mode 0 behaves as if we had two mode 7 screens - and the repeat unit and behaviour unchanged. That would make it unlikely to be a buffer problem, by your reckoning. >Secondly, go into mode 0, and count the number of characters until it >repeats. Multiply that by 8 (to get the the number of bytes before it >repeats) and that'll tell you which address line to look at. Well, 64 characters. That would make it.... 256 bytes, no? Therefore, (guessing) um.... address line 8 (I start counting at 0). SO... uh.... where? Sorry I'm such an electronic idiot. A

28 years, 4 months

FW: Freebie Tape Drive in Milwaukee

by kyrrin2＠wizards.net

Anyone feel the urge to own a TU81 6250BPI tape drive that's in Milwaukee at the moment? Get in touch with this fellow... -=-=- <snip> -=-=- Path: Supernews70!Supernews73!supernews.com!sunqbc.risq.qc.ca!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!europa.clark.net!169.207.30.81!newsfeeds.sol.net!newsops.execpc.com!posts.execpc.com!daily-planet.newsops.execpc.com!usenet From: "Dan Reese" <danreese(a)execpc.com> Newsgroups: comp.sys.dec Subject: TU81E 9-track tape drive available Date: Tue, 24 Feb 1998 07:16:02 -0600 Organization: Exec-PC BBS Internet - Milwaukee, WI Lines: 15 Message-ID: <6cuh95$4md(a)newsops.execpc.com> NNTP-Posting-Host: bacrana-44.mdm.mke.execpc.com X-Trace: daily-planet.newsops.execpc.com 888326245 4813 (None) 169.207.82.172 X-Complaints-To: abuse(a)execpc.com X-Newsreader: Microsoft Outlook Express 4.72.2106.4 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.2106.4 Xref: Supernews70 comp.sys.dec:60814 There is a TU81E 6250 BPS 9-track reel-to-reel tape drive available for the taking in Milwaukee, WI. Has been out of service for over a year, but was in good working order when last on-line. A KLESI adapter is also available for use in a Vax 4000 system. Connecting cables included, along with whatever manuals that can be found. You pick up, but will consider shipping if you absorb shipping costs. Contact: Dan Reese danreese(a)execpc.com -=-=-=-=-=-=-=-=- Bruce Lane, SysOp, The Dragon's Cave BBS (Fido 1:343/272) kyrrin2 {at} wiz<ards> d[o]t n=e=t "...No matter how hard we may wish otherwise, our science can only describe an object, event, or living creature, in our own human terms. It cannot possibly define any of them!..."

28 years, 4 months

front panels

by peacock＠simconv.com

The one thing you could do with a real front panel (not the debugger ROMs and a keyboard/LED display) is debug new card designs. Remember the Morrow S-100 extender card with the built-in logic probe? For those of us who wanted to build our own cards (remember wirewrap too?) but couldn't afford a home o-scope, much less a logic analyzer, the logic probe and single stepping front panel were invaluable. You could actually single step execute an I/O command and see the address and data bus decode on the peripheral card. And when you finished soldering that new 8KB static RAM board full of 2102s, you could see the bit change from 1 to 0 right before your eyes, no better way to find a bad chip or solder joint. The best thing IMSAI ever did was come out with a good front panel, not that wiring nightmare that MITS put on the Altair. I still have a running IMSAI with the front panel (circa 1977), plus an Ithaca Intersystems S-100 with the front panel, which was only a slight improvement over the IMSAI version. I also had one homebrew S-100 with the Wameco front panel, which used hex displays for address and data but otherwise was identical to the IMSAI front panel. Does anyone remember other front panel S-100 cards besides MITS, IMSAI, Ithaca, and Wameco? Wasn't there a Byte-8 sold by Olson Electronics for a while that also had a front panel?

28 years, 4 months

Vector Graghics

by francois.auradon＠worldnet.att.net

Well actually the Vector 4 (accoding to the doc) has both a Z80B and a 8088-2, they can be individually selected through the use of port 0cH and port 0dH. They are both clocked at 5.1 MHz. And yes the Floppies are hard sectored (16) for a total capacity of 630 KB. They can also be eqiped with a 5MB HD ------------------------------------------------------------- Fran?ois Visit the Sanctuary at: http://home.att.net/~francois.auradon >Yes it was. One of my s100 boxen is a Vector MX (s100 crate only none of >the original boards). The MX was z80 powered byt the Vector 4 may >have been 8088(cpm-86 V1). > >Allison >

28 years, 4 months

Photo of Smithsonian microcomputer exhibit

by altair8800＠hotmail.com

A friend of mine was recently in D.C. and took this photo of the Microcomputer exhibit in the Smithsonian Museum. I recognize the Altair and the Sol but what is the Apple prototype sitting on the table? Here is the link to the photo... http://home.att.net/~rwood54741/Museum50.jpg Bob Wood ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

28 years, 4 months

North Star Horizon

by allisonp＠world.std.com

<I did some software work on a Horizon many years ago. As I recall, it ha <two full height 5.25" bays, a good sized power supply behind the bays (o <the right side) and a shorty S-100 card cage on the left, 8 card slots? <the NS motherboard also had some logic on the motherboard, at the rear. <believe there were one or two 8251 serial ports, a baud rate generator, <maybe a parallel port or interrupt controller (look for an Intel 8214 or <28-pin AMD IC)? Err no. The back plane will have two 8251 serial port and a parallel port and supporting ttl for same. It has a heartbeat timer for that can drive interrupts. The interrupt logic is on the CPU ZPB-A and it allows 1-of-8 RST locations to be used (z80 mode 0). there isn't a 8214 in the whole thing if it's a Horizon unless the board with it is not from NS*! BTW, 112 slots though a full 64k system could be configured in as few as three cards! The lineup would be CPU, 64k ram card, disk controller and the IO already built into the mother board(2 serial and 1 parallel). The power supply is responsable for 30% of the total weight and is electrically robust. It was easy to check, mine is sitting here cranking a z80 asm file. Allison

28 years, 4 months

North Star Horizon

by allisonp＠world.std.com

< I think it uses the S-100 bus. According to their manual, North Star <used the same disk controller in the Horizon that they sold for the S-10 <systems. I have a NS S-100 controller. They are the same electricaly and <software wise but maybe physically different. They are the same or close cousins and both S100. NS* prior to advantage was nothing but an S100 house. The first one sold (still have mine) was MDC-A a single density unit that cound address up to three single sided drives. The later MDS-A was a Double density controller for up to four twosided drives. Both were S100, the same form factor and had on board boot proms nominally at the same standard address. The latter DD version would read and write SD media as well. Now as to formats and non NS* controllers. NONE of the FDC chips can read the NS* format but a controller that could is easily built for most any bus or cpu capable of reading data at the required rate and doing the housework inbetween. Allison

28 years, 4 months

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