test-drb July 2001

test-drb@ccmp.vtda.org

301 participants
824 discussions

by mcguire＠neurotica.com

On July 16, Rich Beaudry wrote: > I recently acquired an Osborne One, but it seems to be having a video > problem -- as in no video at all. I did the obvious - played with the > brightness and contrast -- but still nothing. If I press a key on the > keyboard, the floppy starts seeking, so I assume the rest of the computer is > at least partially working, but I get no video output at all. I have NO > docs or schematics, so it's a bit hard for me to test stuff out. The CRT > make no noise at all when power is either turned off or on (no static or > hum, or anything else). Also, I took the cover off, and carefully looked > inside while turning the power on, and the CRT didn't light up, or have any > other response. No light from the CRT's filament? That's a bad sign. If there's enough room in there, it might be a good idea to look carefully at the neck of the CRT and try to identify the filament pins, then check between them with an ohmmeter to see if the filament is open. I have an operational Osborne One here, with the manual...if you want me to look anything up for you, or do any probing, let me know. -Dave McGuire

23 years

Osborne One -- No video.

by Antonio.Carlini＠riverstonenet.com

> Fred Cisin (XenoSoft) wrote: > >YOU just came up with the first clue. Connect a composite monitor and see >if there is video reaching the external jack. >is there any software/magic keystrokes, etc. required to activate the >external video? Do you need that funny little connector to use external video? (Small black thing, marked EXMON). I vaguely remember some warning about ensuring that the box is powered off when inserting or removing the little beastire. (Oh, for a technical manual ...) Antonio arcarlini(a)iee.org

23 years

Osborne One -- No video.

by Robert_Feldman＠jdedwards.com

There must be a shunt on the video edge connector that comes out at the front middle of the case. It just connects the contact on the bottom with the contact on the top of the circuit board. I can email you more info tomorrow if you need it...got to run now. Bob Feldman -----Original Message----- From: Rich Beaudry [mailto:r_beaudry@hotmail.com] Sent: Monday, July 16, 2001 3:49 PM To: classiccmp(a)classiccmp.org Subject: Osborne One -- No video. Hello all, I recently acquired an Osborne One, but it seems to be having a video problem -- as in no video at all. I did the obvious - played with the brightness and contrast -- but still nothing. If I press a key on the keyboard, the floppy starts seeking, so I assume the rest of the computer is at least partially working, but I get no video output at all. I have NO docs or schematics, so it's a bit hard for me to test stuff out. The CRT make no noise at all when power is either turned off or on (no static or hum, or anything else). Also, I took the cover off, and carefully looked inside while turning the power on, and the CRT didn't light up, or have any other response. After powering down, a very careful disassembly showed no physical damage signs -- no burn spots, missing components, broken wires, etc. Any clues? This is the blue case, with the modem, and a composite video jack (female RCA jack) in the bottom right.... Rich B.

23 years

It's Alive, ALIVE!

by mcguire＠neurotica.com

On July 16, Rich Beaudry wrote: > Just wanted to share a very tiny, but nonetheless important moment for me. > Took a homebrewed S-100 power supply, connected it to a nice Wameco > motherboard (thanks ajp!), threw in a Cromemco SCC (thanks Mike for the > monitor and Control Basic), and was greeted by a wonderful "OK >" prompt on > my terminal. "QUIT" out to the monitor prompt (":"), and fooled around a > bit, then a "B" back into Control Basic. > > Not much I admit, but a working SCC, good EPROMs, and a working > PS/motherboard... It felt really good. > > Next up, I added a Cromemco 8K ByteSaver II, and read out some 2708s. I > tried to program a couple, but got stymied. I think I just need to do more > "R"ing of TFM. Neat to finally be able to at least read them out. > > All I need to do is throw in a couple of 16K Static RAM cards, and either a > Cromemco TUART or a Godbout Interfacer, and I'll be rocking a bit! Final > test is the Dynabyte floppy controller! > > Baby steps, I admit, but still felt cool.... Sounds like an extremely gratifying victory. Very cool! Congrats! -Dave McGuire

23 years

It's Alive, ALIVE!

by r_beaudry＠hotmail.com

Hello to all, Just wanted to share a very tiny, but nonetheless important moment for me. Took a homebrewed S-100 power supply, connected it to a nice Wameco motherboard (thanks ajp!), threw in a Cromemco SCC (thanks Mike for the monitor and Control Basic), and was greeted by a wonderful "OK >" prompt on my terminal. "QUIT" out to the monitor prompt (":"), and fooled around a bit, then a "B" back into Control Basic. Not much I admit, but a working SCC, good EPROMs, and a working PS/motherboard... It felt really good. Next up, I added a Cromemco 8K ByteSaver II, and read out some 2708s. I tried to program a couple, but got stymied. I think I just need to do more "R"ing of TFM. Neat to finally be able to at least read them out. All I need to do is throw in a couple of 16K Static RAM cards, and either a Cromemco TUART or a Godbout Interfacer, and I'll be rocking a bit! Final test is the Dynabyte floppy controller! Baby steps, I admit, but still felt cool.... Rich B.

23 years

Kennedy 9100 tape drive info?

by dhquebbeman＠theestopinalgroup.com

> This is definitely not a Pertec-interface drive. > Has two what looked like 36-conductor edge > connectors, plus or minus. Not 50. I'm guessing it might be a StorageTek interface... -dq

23 years

BBC Micro (was: Re: Apple II for into to microprocessors

by Antonio.Carlini＠riverstonenet.com

John Allain wrote: > > > I always 'megger' old transformers and most of them are as good as > > the day they were made. > > -tony > > Tony you lost me here. Kegger I heard of. Megger? A "megger" is a meter so he means he checks the winding resistance ... what's a kegger? Antonio arcarlini(a)iee.org

23 years

Subject: Light Pen for PCjr or PC?

by kapteynr＠cboe.com

You might not believe it, but I actually have a light pen on my Altair 8800. There was an article in one of the old hobbyist magazines how to do it, and we did it. (my little brother and I) We have a Processor Technology VDM-1 "video display module" in the Altair. This was a very popular add-on module. The VDM-1 allows software to read the current horizontal and vertical sync registers. To make a light pen, we simply put a phototransistor in the end of an empty pen and strung some wires from it to a prototyping card in the Altair. We have a simple circuit that triggers an interrupt whenever a certain threshold is hit The interupt processing software then reads the current horizontal and vertical scan positions from the VDM-1 card. The VDM-1 only has character-level black&white graphics, but we could still draw on the screen by reversing the background of the character blocks. We had never heard of the "mouse" when we did this, so it seemed really high-tech and was quite fun. The mouse is better though :-) -Rob -----Original Message----- From: McFadden, Mike [SMTP:mmcfadden@cmh.edu] Sent: Monday, July 16, 2001 11:40 AM To: 'classiccmp(a)classiccmp.org' Subject: RE: Subject: Light Pen for PCjr or PC? >From: Michael Brutman <mbbrutman(a)chartermi.net> > > >I've never seen a light pen in use on any machine ... I've >only seen them in pictures. How do these things work? >Does anybody know how to obtain one or have information >on how to build on? > > >Thanks, >Mike As I understand it the light pen detects the electron beam on the CRT display as it passes the end of the pen and can decode from the timing where the pen is located. Somewhere I have a light pen kit that was used to emulate certain types of IBM terminals. Many hospitals used light pens to move through the menus for patient registration and order entry. Pointer to some more information http://www.ftgdata.com/products/lightpennav.html Mike mmcfadden(a)cmh.edu

23 years

BBC Micro (was: Re: Apple II for into to microprocessors

by pete＠dunnington.u-net.com

On Jul 15, 20:13, Tony Duell wrote: > Hmmm... I have the US Beeb schematic somewhere.... OK, found it. > > The US version of the Beeb can output NTSC video. > Having found the US Beeb schematic, that's what they did, almost. The > cystal is 14.318MHz, and there are a couple of other capacitor changes in > the oscillator circuit. The flip-flops are re-numbered (IC46 -> IC96 and > IC44 -> IC97) but the circuit is unchaged electrically. And the output of > IC97b goes to one side of link S32. The centre pin of the link goes to > the xor gate input (now IC99d), the other outside pin is grounded. Set > the link one way and you have PAL, set it the other way and you get NTSC. > I think all BBC B+ machines have this link as standard (even the UK ones). Yes, I they do (mine has it, and it's shown on all the diagrams) and now you mention it, it sounds familiar. Or more accurately, I remember seeing soething about converting US machines back to UK spec (or UK-usable spec, at least). One Acorn dealer re-imported a lot of unsold US and German Beebs some years ago. For readers unfamiliar with the BBC family, the original machines were the Model A and Model B; the A lacking certain components present in the B to provide multiple-ROM support, printer port, user port, serial port, analogue port, 1MHz bus or Tube (2nd Processor) ports, and only having 16KB RAM instead of 32KB. However, upgrading was easy (and both official and unofficial kits were readily available) and there was no difference at all between a B and a fully-upgraded A. Both could be further extended with a disk interface, proprietary network interface, and various third-party addons. Then came the B+. This looked similar from the outside, but had a redesigned PCB with 64K of RAM, some of which was used to "shadow" the screen and OS workspace. There was a 64K upgrade for it, which made it a 128K machine (though you couldn't actually do much with the extra RAM except put BASIC and it's variable space in it). It also used a 1770 or 1772 disk controller rather than the 8271 in the B (though you could fit an 8271 to a B+ or a 1770 to a B). That was succeeded by the Master 128 -- externally as well as internally different. It had a numeric keypad added, used double density disks by default, had two ROM cartridge slots, more comprehensive MOS (machine operating system), several utility ROMs that would be extras for a B/B+ were built in, and it used a CMOS 65C02. It also used more custom chips :-( There were some coprocessor addons for the 128 and other members of the family launched shortly after it, like the Master Compact (a two-box solution) and the ill-fated Econet Terminal (terminal and network software only, no BASIC and no extra interfaces, didn't sell well and was quietly dropped). After that, in 1987, came the Archimedes range, based on the ARM processor. Initially the A310 with 1MB, which still had red function keys to denote its standing as a BBC Microcomputer, then the A440 (grey keys, not a BBC Micro). And after that, the A3000 and its successor the A3010, which were the last with BBC endorsement and once again were single-box systems (like an Apple ][ or Amiga 500, etc). There were many other models in the ARM-based range, ending with the RISC PC, but none were BBC Micros. Despite all this, when someone refers to "a Beeb" they usually mean a Model A or Model B, not a B+ or later. Acorn trivia: the plastic case of the A3000 was deemed not strong enough to support the weight of a multisync monitor, so a sheet-metal stand was devised. The front of it sat on the strong edges of the A3000 case, the rear was supported on a bent-over section. Because it clung to the case, and from the front looked like the outline of a Klingon warbird, it became known as "the klingon". -- Pete Peter Turnbull Network Manager University of York

23 years

thunderstorm damages!

by mmcfadden＠cmh.edu

Many times it's not the surge through the power line but through the phone line that gets you. I've lost two modems that way, one of my friends lost his motherboard with a built-in modem because of lightning. I knew the lightning would be a problem when I saw the power transformer and the pole burning and then I found part of my phone wiring was toasted. My UPS warbles all the time from voltage and line variations. I've got both my router and cable modem plugged in to it. Maybe I'm paranoid, of course I live on a lake in Missouri where trees fall on the power lines all the time, we have thunderstorms and the occasional tornado and the all too common fried squirrel on the transformer. Mike mmcfadden(a)cmh.edu

23 years

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test-drb July 2001