test-drb September 2001

test-drb@ccmp.vtda.org

256 participants
661 discussions

by gessler＠ucla.edu

All you Tekkies out there... I just pulled my old Tektronix 4051 out of the garage (no I don't want to sell it), plugged it in, turned it on and ... and ... and ... Well all the lights lit, the memory CRT bloomed, and that was that. Screen wouldn't clear and the machine wouldn't respond to any keystrokes. It's frozen... Well it worked fine when I put it in storage and I was wondering if anyone had any experience getting these to work after years without juice? I seem to recall that the machine goes through a self-test on power up: the "busy" and "i/o" lights light and after a few seconds they go out and a square cursor appears on the screen. Does anyone remember what the self-test looks for? I'm thinking it may try to trigger the tape to rewind and wait for the results. I don't know why any electronic part would fail after years of storage but would seem likely that a tape drive motor might seize up and stop the machine from completing its test. It would be an easy matter to free up a motor and a more difficult matter to diagnose a parts failure. Any ideas before I take the thing apart? Thanks in advance... Nick Nicholas Gessler gessler(a)ucla.edu Box 706, 22148 Monte Vista Drive Topanga, CA 90290-0706 310.455.1630 (home office) 310.825.4728 (UCLA office) 310.825.7428 (UCLA fax) Special Projects, UCLA Center for Digital Humanities Founding Co-Director, UCLA Center for Social Complexity (a.k.a. Center for Computational Social Science) Founding Co-Director, UCLA Social Interfaces & Networks / Advanced Programmable Simulations & Environments (SINAPSE) Instructor, Geography, Computational Geography Track: Simulations, Cartography, Artificial Culture In preparation - "Artificial Culture - Experiments in Synthetic Anthropology." Web Portal: http://www.bol.ucla.edu/~gessler

23 years, 2 months

Central Point Option Board vs Deluxe Option Board

by mark_k＠totalise.co.uk

Hi, A couple of people requested the Option Board Software. I created image files of the original floppies and uploaded them to http://www.btinternet.com/~mark_k/Option_Board_v5.4_3.5.bin.gz http://www.btinternet.com/~mark_k/Option_Board_v5.4_5.25.bin.gz After downloading decompress using gzip, then use your favourite disk-image- writing program to write to a (formatted) floppy disk. -- Mark

23 years, 2 months

FYI: Proper flag uses per Public Law 93-344

by rhblakeman＠kih.net

Just for those who aren't aware of the proper uses and display of the US flag in this moment of everyone just having to display it lately, here's a well done resource for reference. This is a guideline made from US Public Law 93-344 and done in a layman's format so it's easy to grasp and use. It might even be a good idea for local newspapers to print a variation of this once to inform people that don't know that they may be "doing it wrong" http://www.state.wi.us/agencies/dva/museum/flaguse.html

23 years, 2 months

Report from CARA Hamfest

by wh.sudbrink＠verizon.net

Went to the Columbia (Maryland) ARA hamfest this morning. By far, the most successful, in vintage computer terms, hamfest I've ever been to. Arrived at 6am. Dark... Walked around through the little bit of fog, squinting at the tailgating stuff already out. Silly me, forgot to bring a flashlight. Talked to some people and got a line, maybe two, on an ASR 33. As the sky gradually brightened, made my first score, a box of S-100 cards and motherboards. The guy wanted $20. I was so amazed to find anything that interesting that I forgot to haggle and handed him a twenty. Next I found a large pile of 50 pin twisted pair rainbow wire (perfect for 8 inch floppy cables) for $1. It quickly got lighter and the fog burned off. Now I could see the following of classiccmp interest (all of which I passed on): A pile of 20 or so Commodore 64s with a sign "2 for $5" A large collection of SGI boxes, Indigos, etc. A large collection of Sun boxes and monitors. A number of Atari boxes of various makes. A table with 10 or so old Mac boxes and a Next slab. A couple of CoCos. A lot of tailgaters were still setting up, but it was 8:30 and I had to leave. On my way out, a flash of "S-100 blue" caught my eye. In an unattended box labeled "project enclosures, $5 for the box, slip money in drivers side window" was a really nice, clean NorthStar 5 1/4" disk enclosure with power supply, but no drive. I didn't need all the other Radio Shack style project boxes that were also in the box, so I just took the N* box and put $2 in the window. I hope some other CC'ers made it to this one, I'll definitely be back next year.

23 years, 2 months

changing Aviion monitor refresh setting

by red＠bears.org

1) Power on the machine. 2) Wait approximately ten minutes. 3) Press 'reset'. 4) Wait a further thirty seconds. 5) Type <CTRL>-V on the console keyboard. The machine should beep. 6) Type '1' to set the video system to 70 Hz sync or '2' for 60 Hz. additionally, the default mode for the serial console (which the system will automatically use if there is no keyboard plugged in at power-on) is: 9600-E-7-1 Good luck. Hopefully this will help somebody get his Aviion going. ok r.

23 years, 2 months

Organization tips?

by mcguire＠neurotica.com

On September 19, Chuck McManis wrote: > So does anyone have a preferred way in which they organize all the many > hundreds of bits of stuff you need when you are keeping older computers alive? For storing stuff in boxes...I avoid cardboard nowadays...I've been replacing them with those plastic "tubs" that one can purchase at discount stores. They last longer, are waterproof, and more stackable. They've also considerably cut down on the dust level in the house. -Dave -- Dave McGuire Laurel, MD

23 years, 2 months

Mild OT: fixing an eMate

by spectre＠stockholm.ptloma.edu

I'm looking for parts to repair a dead? eMate 300. The screen is basically cracked in half! Fortunately, the rest of the unit is intact. For those who don't know what one is, this is basically a Newton-based laptop and a very nice little machine. I'm scoping around for parts but was wondering if someone had a dead one with an intact LCD they might be willing to part with. Ironically, it was damaged in a classroom demonstration of how difficult to break it was. The professor nailed it the first time. :-/ -- ----------------------------- personal page: http://www.armory.com/~spectre/ -- Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu -- In memory of Howard Caine --------------------------------------------------

23 years, 3 months

Mainframe stuff...

by mcguire＠neurotica.com

On September 19, jkunz(a)unixag-kl.fh-kl.de wrote: > BTW a stupid question: What is a 8700? Is it SBI based like the > 11/78[05] and 86[05]0, or is it XMI / VAXBI like the 85x0 or 6k VAXen? > I asume that a 8700 is a 8600 in a biger enclosure? The 8700 and the 8600 are very different machines. The 8700 uses VAXBI, and is mounted in a chasiss similar in size to that of the 8600. I don't think there's any XMI in there. Incidentally, the 8700 can be turned into an 8800 by plugging a second CPU card set into the machine. -Dave -- Dave McGuire Laurel, MD

23 years, 3 months

Address Decoding for Dummies! (was: SPDT Dip Switches...

by pete＠dunnington.u-net.com

On Sep 22, 13:11, Roger Merchberger wrote: > I did mention that I was primarily a softee-ware guy -- and when > dealing with chips I have a tendency to think of them *as software* -- > like: if you try to write to a ROM, what happens? Nothing. (duh...) Well, not unless you use "more interesting" voltages :-) > I > looked at the chip specs for the demux, and you have inputs & outputs... In > my mind (at first), your suggestion was "ramming 5V down an output port" > and sometimes I have to stop & think that "those ports are just a bunch of > gates jammed together on a chip to serve one purpose" and doing stuff like > that is not a "Bad Thing (TM)." :-) > My board isn't a "complete" board -- it's to be designed to make > experimenting much easier by having flexible on-board address decoding, and > (at least for my purposes) I want "one address per switch", so I'm not sure > if the MUX suggestion is what I want. As of right now (but I'm still > researching CoCo memory maps) I'm looking to have an 8K ROM socket at the > "normal" location ($C000-DFFF) w/jumper as to whether or not it will > auto-start (jumpering the Cart signal to the Q line) and I'm looking at > having the address decoding for my I/O ports at $FF50-3 & $FF60-3, but if I > want *just* $FF51 & $FF53 to be decoded & $FF50 & $FF52 to be ignored, I > want to be able to switch them individually. > (Originally, my design was just going to have 1 address decoded from each > "bank", but then I realized that if I wanted to interface "most anything" > like a PIA, UART or a FDC that it wouldn't work.) Let's see if I'm interpreting this correctly. I think you want to be able to decode addresses, but sometimes you want to be able to provide (let's say) two "enable" outputs, each active for a separate group of addresses (maybe two different ranges of four addresses each), and sometimes you want to be able to provide more finely selected enables (maybe responding to only one address in each range). I can see why you'd want to that if one day you are using a UART that needs four addresses and another time you use a a PIO or VIA that needs 8 or 16 addresses. A couple of ideas that come to mind are using a PROM or PAL to do the decoding. A PAL or GAL would probably operate faster than a PROM, but it might be easier to program a PROM (depending on how used you are to building tables for PROMs, logic rules for PALs, and what programming tolls you have access to). For example, suppose you have a PROM with 8 address and 4 data outputs. You could fill it with data such that certain data outputs were at the appropriate "active" level if (and only if) 6 of the address lines were in a certain state, ie were driven with a certain address(es). By tailoring the data appropriately, you could arrange it so that the outputs took account of all 6 address bits, or just (say) four). The other two address bits I'd use as a function selector: if both are low, the output is active for a range of addresses (only 4 bits significant); if one is high, respond to the first two addresses in the range; if the other is high, respond to the upper part of the range; if both high, respond only to the highest single address in the range. Or something like that, to suit the job in hand. Depending on the exact requirement, you might still be able to do this with a MUX or two. A multiplexer is a very useful general-purpose logic element, widely used as a circuit building block, not just for the obvious "if the clock phase is high, select the refresh/video addresses; if low, select the CPU addresses" sort of operation. > For anyone here who does their own hardware designing, what software do you > use? I've tried "Protel 99 SE" and CircuitMaker 6 (student version) -- and > a few others, and I must say that I'm not keen on most anything I've tried > compared to "good ol' AutoCad". I use an assortment. Often I use the drawing package from RISC OS on one of my Acorn machines. From time to time I've used 'pcb' on a Unix system. > Oh, I've found a really good site to purchase all manners of circuit board > "stuff" w/really good prices, too: > http://www.web-tronics.com/printed-circuit-board-supplies.html That's encouraging. Completely home-made PCBs seem to be a relativley rare occurrence in the US, at least compared to here. Over here, almost every secondary school, college, and university makes PCBs and there are still magazines publishing designs which enthusiasts photocopy onto film (OHP acetates, aka viewgraph foils for you colonials) and then apply to photoresist copperclad board. In the USA, as far as I can see, most people tend to pass the artwork or plotfiles to professional PCB houses to be made up. Lots of people do that here too (I'd probably not try to etch my own board for a really densely packed device using PGAs, for example) but there's still a strong tradition of using your own ferric chloride (not in the wife's best stainless steel sink, though). While there's nothing at all wrong with either method, I'd caution anyone trying it, that layout software (or dry transfers) tends to be suited to one or the other but not both. For the professional house, you are more likely to want nice round pads and not too many different sizes. You can use thin tracks, and pads with fairly small margins of copper round the holes. However, for truly homemade, handetched boards, there's usually more variation in the quality of the image transferred to the board, so very fine tracks are not such a good idea. Moreover, they won't normally have plated-through holes, so it's wise to use larger pads which won't come unstuck too easily -- often oval pads for ICs, which have a relatively large copper area yet are still narrow enough to leave a gap to get tracks between the pins. Lots of PCB layput software isn't capable of doing anything other than simple round (or square or symmetric octagonal) pads and is therefore much less useful for home-etched PCBs. No offence intended Roger, but I think your IC pads on the CoCo board are smaller than I'd personally be happy with for a home-etched and -drilled board without plated holes. (See http://www.dunnington.u-net.com/tmp/coco_pcb.jpg for a modified fragment) BTW, did you notice the tracks going through the pins on pins 13 and 14 of the leftmost LS244? -- Pete Peter Turnbull Network Manager University of York

23 years, 3 months

Excess Merchandise

by close＠2wongs.com

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23 years, 3 months

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test-drb September 2001