test-drb May 2001

test-drb@ccmp.vtda.org

273 participants
642 discussions

by pete＠dunnington.u-net.com

On May 16, 21:59, Louis Schulman wrote: > Well, I just got a fabled but seldom seen Exidy Sorcerer. It has a > power supply problem (including the need to be converted back from 220 > to 110V) but I am working on that. That should be fairly easy; you just change the transformer connections inside the case. The 110V setting has two primary windings connected in parallel to the mains; for 240V the black/red and black/yellow wire would have been cut at the mains filter and joined together, putting the two windings in series. There weren't different units for the two voltages; Exidy literally cut the wires as I describe above, and joined them together for the European sales. If it's been set for the "wrong" voltage, it probably has been set for the wrong vertical sync frequency as well. How you change this depends on whether it's a Mark I or Mark 2. If it has three rows of DRAM, or sockets for three rows, it's a Mark 2. For a Mark I, there are 3 jumper sets on the underside of the PCB, beside the ICs in positions 3B and 4B. The first set is a pair of square pads between the rows of pins of 4B; connect them for 60Hz, or disconnect them for 50Hz. The second set is a group of 3 pads between 4B and 3B. Two are nearer 4B, one is nearer 3B, and they're arranged in an L shape. Connect the middle of the L to the other one near 4B for 60Hz; connect the middle of the L to the one nearer 3B for 50Hz. The last set is the other side of 3B; connect the two pads nearest 3B for 60Hz, connect the one nearest row A to the one furthest from 3B for 50Hz. For a Mark 2, it's easier. There's a 4-pole DIP switch at positin 11A on the top side of the PCB. Switch section 1 off for 60Hz, on for 50Hz. > The Sorcerer was a contemporary of the Apple II, Commodore Pet and > TRS-80 Model 1. It was unique in a number of features, including its > use of an S-100 expansion box. In many respects, it appears to have > been inspired by the SOL 20. > > Info on the web in very sparse. I have nothing but the bare CPU, and > photocopies of some manuals. I would like any info anyone has > available, software, manuals, hardware, etc. Will pay good bucks, or > trade from my vast collection of interesting stuff. I have the BASIC ROMs, the original monitor ROMs, patched (bugfixed) monitor ROMs, images of the WP PAC ROMs (anyone got images of the Dev Pac ROMS? Or a WP PAc manual? I used to have all these...). I have both Technical Manuals and the Software Manual, the smaller of the two BASIC manuals, the S100 Expansion Unit Technical Manual, notes on the hardware bugs (eg the RS232 misdesign on the Mark I, for which I have a fix), and some expansion options (eg upgrading 32K Mk1 to 48K). I'm not willing to part with manuals, but I'm happy to lok anything up for you, and the ROM images and my source code is at http://www.dunnington.u-net.com/public/ExidyROMs/ I've also got some games and other software (not much, I'm afraid, things like Breakout, Galaxians, BASIC Toolkit) which aren't on line, but might be available if you can't find anything elsewhere. I assume you've found: http://www.trailingedge.com/exidy/ http://www.heydon.org/kevan/collection/manufacturer-exidy/sorcerer.html http://www.tardis.ed.ac.uk/~alexios/MACHINE-ROOM/Exidy_Sorcerer.html http://www.lisp.com.au/~michael/exidy/ http://utopia.knoware.nl/users/stuurmn/exidys.htm http://www.digidome.nl/exidy.htm There are some errors in the last two or three pages (for example, it never used a Z80A, and there was never any version but the 2.1MHz), but still useful information. -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

Exidy Sorcerer

by pete＠dunnington.u-net.com

On May 17, 19:55, Louis Schulman wrote: > Thanks, Peter. This is very helpful. I had figured out reversing the > serial to parallel wiring, but didn't know about the dip switch > settings. Mind is obviously the Mark 2. My original one was, too. However, I sold it in 1982 and the one I have now is a Mark 1. Does yours have 48K? It's easy to add extra memory to bring it up to full spec, but there is a timing problem that affects some boards when you fit the third bank. I was unlucky and spent days trying to figure out what was wrong when I bought the extra 8 chips, so eventually I sent it to a Sorcerer dealer/repeairer and he not only modified it but gave me a diagram showing the fix. > Is there some way I could get copies of the manuals? Not very easily. I don't have access to a scanner at the moment. However, David Williams has quite a lot on his Trailing Edge website. > Also, is there > some way to create a ROM Pack? I really could use the Standard Basic > ROM pack. Assuming I burn the chip, what else is there to the circuit? That's not too hard. The Pac consists of a PCB with 4 x 2316 ROMs and a 2-chip decoder circuit, all mounted inside an 8-track tape cartridge shell. It's perfectly possible to build a replacement using a single 2764 and a 74LS10. With a little care, the bare PCB can be inserted into the cartridge slot, so you don't even need to cannibalise a "rare" 8-track cartridge. I have a drawing for such a PCB which I'll put on my website for you. Look for it at http://www.dunnington.u-net.com/public/ExidyROMs/ROMPacPCB.ps Minor caveat: although the date on the file tells me I drew this years ago, the need to use it went away and I never built a prototype. It should work, though. There are 17 places to put track pins to connect one side to the other, two places to put capacitors (a 6V 10mfd tantalum and a 100nF ceramic), at the end of the 74LS10 location, and both IC locations indicate pin 1 by a square (instead of oval) pad. The ROM images are already there, just concatenate them (in order) to make a 2764. -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

Books available

by gregorym＠cadvision.com

>I have some vintage books that are surplus to requirements, and are free* >to any list member who wants to pay shipping. They are: > <list snipped> > E-mail me off-list if >interested. Take one, take 'em all. > Sorry for replying to my own message, but that last line is misleading. I meant to say: "Take one OR take them all". You don't have to take all of them. First come, first served. Mark.

23 years, 7 months

Books available

by gregorym＠cadvision.com

I have some vintage books that are surplus to requirements, and are free* to any list member who wants to pay shipping. They are: 6809 Assembly Language Programming, by Lance Leventhal (Osborne/McGraw Hill, 1981) Motorola MC6809-MC6809E Microprocessor Programming Manual (May 1983 printing) PL/1 Structured Programming 2nd Ed., by Joan K. Hughes (John Wiley & Sons, 1979) Structured PL/1 (PL/C) Programming, by Jean Paul Tremblay et al. (McGraw Hill, 1980) Structured Programming Using PL/1 and SP/k, by J.N.P. Hume and R.C. Holt (Reston Publishing Co., 1975) Computer Programming RPG II, by Gary Shelly and Thomas Cashman (Anaheim Publishing, 1981) Comprehensive Structured COBOL, by Gary Popkin (Kent Publishing Co, 1984) COBOL Programming A Structured Approach 2nd Ed., by Peter Abel (Reston Publishing, 1984) VAX Basic, by David Weinman and Barbara Kurshan, (Reston Publishing, 1983) 370/360 Assembler Language Programming, by Nancy Stern et al. (John Wiley & Sons, 1979) All are in good, but used, condition. Most were somebody's university textbooks at one time, so there are some marginal notations. Shipping is from T2J 5H9 (Calgary, Alberta, Canada). E-mail me off-list if interested. Take one, take 'em all. Cheers, Mark Gregory * Donations of unneeded Amiga books, magazines, hardware, or software always gratefully accepted.

23 years, 7 months

74xx orgin

by pete＠dunnington.u-net.com

On May 17, 22:11, Tony Duell wrote: > > Yes, a common pitfall. I got bitten by that :-) And the 74150 has the > > same number and arrangement of pins as the 74ALS150, but one is 0.6" wide > > and the other is 0.3" wide! > > Most of the 24 pin chips in the 'modern' familes (things like the 74F181 > and 74HC154) are 0.3" wide. The 'traditional' ones (74181, 74S181, > 74LS154, etc) are 0.6" wide. Don't ask how I found that out. > > Suffice it to say I have commerical instruments where the PCB was set out > for a 0.6" wide chip. In said space is a header plug, soldered to which > is the 0.3" 'modern' version with the pins bent out sideways. :-) A solution I've seen is more "three-dimensional". Take one 24-pin 0.3"-wide wirewrap socket. Bend the pins so they fit into a 0.6"-wide socket. Fit new IC to "upper" socket and fit this to the "lower" one. If liked, mould "power bulge" into the hood. Or cut ventilation hole. -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

Slicing open the top of a 48T02 Sun Sparc chip to replace battery is that thing hollow or filled with epoxy?

by claudew＠videotron.ca

Hi I am considering slicing open the part epoxyed to the top of a 48T02 chip to replace or hook up a new 3VDC source. I dont wanna buy a new chip.... My plan is to use a Dremel type cutting wheel and do a "lobotomy" on the module fitted on top of the chip. Then, either connect a new 3VDC source to this (2 alkalines in a battery holder) or simply replace the cells inside. If the thing (the top module with the batt and osc) is not filled with epoxy I imagine this can be done...does anybody know if that module is "hollow" and removing the top will reveal the components inside...??? Or will I just be cutting through solid plastic/epoxy??? Other method would be to slowly grind top of module until components inside are revealed... Alternative method is revealing the wires coming from top part to chip by digging into epoxy on one side and hooking up there (from sun NVRAM faq)... Thanks Claude

23 years, 7 months

Using audio cassette

by david_j_findlay＠yahoo.com.au

Hello I am a new member of the list in digest mode. I have read quite a bit about the early homebrew computer club days and processor techniques. I am currently designing my own computer and want to come up with a easy cheap method of mass storage. I have been thinking about hacking a tape recorder's read/write/erase heads and support equipment into my computer. I would just make a small modem thing to turn my data to sound and record it on the tape. Using a 90 minute tape, with a 10 second sector size, I would put a File allocation table at the start of the tape and that would tell the machine where to go to get a piece of data. Has anyone experimented with this sort of set up? I figured on audio tape because they are small, robust, and cheap. The computer will only be 16-bit so I don't think the speed of the storage would be a problem as my files won't be that big. It's got to be better than paper tape anyway. BTW, would anyone happen to know where I could find circuit diagrams/logic diagrams for either the PDP6 or PDP10? Thanks, David P.S. Could you please CC' your response to me? Otherwise I won't see your replies for a week... :-) -- David Findlay ---------- Email: david_j_findlay(a)yahoo.com.au Homepage: http://users.bigpond.com/nedz/ Segmentation Fault. (Core dumped)

23 years, 7 months

destinking the computers.

by mmcfadden＠cmh.edu

Slightly OT. Yesterday I listened to a National Public Radio, NPR, segment on people who clean up crime/medical scenes. An example was a person who died in their bathroom and wasn't found for 1 month. They talked about odor removal, they use active enzymes to remove any organic remains. They wore tyvec suits, respirators, double gloves, boots and goggles. Basically they tore out the sheetrock, tile and carpet because the blood and body fluids seep everywhere. Lots of problems with maggots. Company's name was Bioclean. Two ladies with strong stomachs. I'd bet they could destink a computer. Morbid humor on, no offense intended, may not be humorous Probably could clean up after suicidal Microsoft windows programmer. Back to normal Mike mmcfadden(a)cmh.edu

23 years, 7 months

Slicing open the top of a 48T02 Sun Sparc chip to replace battery is that thing hollow or filled with epoxy?

by pete＠dunnington.u-net.com

On May 17, 10:55, Claude.W wrote: > I am considering slicing open the part epoxyed to the top of a 48T02 chip to > replace or hook up a new 3VDC source. I dont wanna buy a new chip.... > > My plan is to use a Dremel type cutting wheel and do a "lobotomy" on the > module fitted on top of the chip. > > Then, either connect a new 3VDC source to this (2 alkalines in a battery > holder) or simply replace the cells inside. It's a single lithium cell inside > If the thing (the top module with the batt and osc) is not filled with epoxy > I imagine this can be done...does anybody know if that module is "hollow" > and removing the top will reveal the components inside...??? Or will I just > be cutting through solid plastic/epoxy??? It's solid. My colleague James Carter did this for one of his Suns, and he has a picture somewhere, showing a (replacable) battery fitted to the top. I can't find the picture on his web pages, but he mentioned it recently in response to a similar post on this list, so look through the archive... -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

74xx orgin

by pete＠dunnington.u-net.com

On May 17, 16:43, John Honniball wrote: > I've checked my "System 74 Designer's Manual", and it's I no longer have my really old Texas TTL data books -- the oldest I have is 1982 -- but didn't one of th eold ones have a short chapter describing the evolution of TTL, S and H series, and LS? I thought it might have dates. > But an oddity did show up: the chip pinouts sometimes > differ between ordinary 74 TTL and the 74H version. A 7401 > has a completely different pinout from a 74H01, for > instance. And a 7454 has one less input than a 74H54 (it's > an AND-OR-INVERT chip). I hadn't spotted that before. Yes, a common pitfall. I got bitten by that :-) And the 74150 has the same number and arrangement of pins as the 74ALS150, but one is 0.6" wide and the other is 0.3" wide! -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

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test-drb May 2001