test-drb January 2002

test-drb@ccmp.vtda.org

303 participants
1201 discussions

by jhellige＠earthlink.net

Well today I got my NeXT Dimension board fully functional with 32MB of RAM installed. Unfortunately the RAM came out of my slab. I am asking this here due to the number of SIMMs I am now in need of. If anyone has the following and would like to sell them, please let me know. 16 - 4MB 30pin SIMMs, 100ns or better, parity or non-parity (as long as they all match), low profile preferred. These are to replace the 1MB SIMMs currently in my Cube's '040 mainboard. 8 - 4MB 72pin SIMMs, 80ns or better, 1M x 32 or 1M x 36 (as long as they all match). These are for my slab to replace the SIMMs I pulled for use in the Dimension board. Thanks Jeff -- Home of the TRS-80 Model 2000 FAQ File http://www.cchaven.com http://www.geocities.com/siliconvalley/lakes/6757

22 years, 6 months

68010 (was Re: Mac IIci)

by pete＠dunnington.u-net.com

On Jan 14, 14:26, Ethan Dicks wrote: > > --- Richard Erlacher <edick(a)idcomm.com> wrote: > > I do believe the main reason for the 68010's appearance in what was > > previously a number of 68000 applications was that it could support > > virtual memory, while that was awkward on a 68K. > > That's my recollection as well. There are two relevant differences. The first is that on the 68000 (and 68008), reading the system byte in the status register isn't privileged, so MOVESR works in user mode as well as supervisor mode. In the 68010, that was corrected and an extra opcode was added to allow reading the user byte (condition codes) in user mode. The second difference is that the 68010 has the VBR (vector base register) so different interrupt/trap vectors can be used in different modes; the vector base is fixed in the 68000/68008. There's no difference in things like address range, modes, MMU interfacing, etc. Those changes came with the 68020. The other changes were improvement to the microcode, which made loops faster. -- Pete Peter Turnbull Network Manager University of York

22 years, 6 months

Info request : HP 9892A card reader

by hansp＠aconit.org

Hi all, We have an HP 9892A card reader which appears in decent shape. We would like to interface it to a PC if possible. It is a rebadged Documation M600. Anyone have docs or info about this model and its interface? Regards, -- hbp

22 years, 6 months

68010 (was Re: Mac IIci)

by mcguire＠neurotica.com

On January 14, Christopher Smith wrote: > > I know that some model of UNIX PC had room for a full-height MFM drive > > under a hump (most only had room for a half-height). It was > > too little, > > too late, but you could drop a lot more than 40Mb inside - maybe 80Mb > > or more! :-) > > IIRC, that was the second UnixPC model that was never released. (7400?) It was also supposed to have a color screen. That said, I suppose it wouldn't be difficult to run the drive interface cable through a plate in the back of the machine, if you can find a plate that will fit it, and has a hole for a connector that you can run to an external drive chassis. Umm, no, that was the 3B1. It was most definitely released, as I've had several of them. I used to run Seagate ST4096 80MB drives in them. I'd kill for one with a color display though. :) > On the other hand, there are MFM to SCSI bridges, I believe, and I wonder whether you could just use one of those and run some 1GB or so disk on it. Those bridges typically go the other way, to put MFM drives on a SCSI bus. I'd imagine it'd be pretty difficult to build one to go in the other direction. -Dave -- Dave McGuire St. Petersburg, FL "Less talk. More synthohol." --Lt. Worf

22 years, 6 months

OT: RE: Mac IIci

by dhquebbeman＠theestopinalgroup.com

> But A/UX sucks humongous hairy sweaty donkey balls. has anyone every noticed that *nothing* ever sucks tiny little dainty hairless donkey balls? ;)

22 years, 6 months

Prophylactic replacement of electrolytic capacitors?

by pete＠dunnington.u-net.com

On Jan 14, 15:52, Rob Kapteyn wrote: > I have not yet tried this yet -- > In theory, electrolytics can be re-formed. > There is a very thin aluminum oxide layer that disappears after a long time. > Running current through the cap will rebuild the insulating layer until current will no longer go through it. > > I want to reform the original capacitors in my Altair "in place" -- i.e., without unsoldering them. > > I have the following setup in mind: > > 1. Insulate the computer from the world -- unplug it and put it on a rubber table. > 2. Use ultra mini test clips to connect to both leads of a capacitor. > 3. Connect the test leads to one of those lab power supplies that have adjustable DC voltage and a milli-ammeter. > 4. Connect + on the lab power supply to + on the capacitor (very important). > 5. Start at zero voltage and increase slowly while looking at the ammeter. > 6. Stop increasing the voltage when the ammeter reads anything more than a few milliamps. > (If it draws too much current, the capacitor will heat up and may blow up) > 7. Wait for the current on the ammeter to drop to zero. > 8. Continue to increase the voltage, and wait for the ammeter to drop until you reach the rated voltage limit of the capacitor. > 9. Repeat for every electrolytic cap in the computer. > > Has anyone done this ? > Will it work ? I've not done that in-circuit, but it might work. There are some gotchas. If you're talking about power smoothing caps, any voltage you put on the cap will also be powering the rest of the circuit. Disconnect any transformer. You don't want to feed them DC. Also, the current drawn by the rest of the circuit will make it impossible to gauge the leakage current in the capacitor. If you're talking about any other capacitor, putting a voltage on it may provide power to some signal line connected to an unpowered device, which the device may not like. In particular, TTL doesn't like power on some signal inputs when there is a ground connection but no Vcc. In either case, the voltage rating on the capacitor is likely higher than the maximum for the logic ICs, and TTL in particular does not like excessive voltage (NMOS is more tolerant). Don't exceed the lowest maximum-voltage rating of any device on the board. Of course, you're assuming that the capacitors need reformed. They might not (but it's good practice to assume they might). If you can't remove them without risking damage to the PCB, I would try feeding power into the board through a current-limited supply at a low voltage and gradually winding it up to the normal value over a period of several tens of minutes. If they've completely dried out, they're dead anyway. Stop if the current shoots up, or seems too high -- you probably have a short. Is an Altair board like a typical S100 board, fed from an 8VDC unregulated supply, and with on-board regulator? If so, just use a bench supply as above. -- Pete Peter Turnbull Network Manager University of York

22 years, 6 months

68010 (was Re: Mac IIci)

by mcguire＠neurotica.com

On January 14, Ethan Dicks wrote: > > used the 68010 even though they had rather limited HDD > > resources. It would have worked better with two drives, methinks. > > I know that some model of UNIX PC had room for a full-height MFM drive > under a hump (most only had room for a half-height). It was too little, > too late, but you could drop a lot more than 40Mb inside - maybe 80Mb > or more! :-) If memory serves, the one with the half-height bay was called the 7300, and the full-height version was the 3B1. They were the same otherwise; I swapped a few out from damaged machines many years ago. They sure were great machines. I wouldn't mind having one for posterity. -Dave -- Dave McGuire St. Petersburg, FL "Less talk. More synthohol." --Lt. Worf

22 years, 6 months

OT: RE: Mac IIci

by dhquebbeman＠theestopinalgroup.com

> On Mon, 14 Jan 2002, Douglas Quebbeman wrote: > > > > But A/UX sucks humongous hairy sweaty donkey balls. > > > > has anyone every noticed that *nothing* ever sucks > > tiny little dainty hairless donkey balls? > > I bet tiny little dainty hairless donkeys do... Don't they call those "gerbils"? <ducking> ;)

22 years, 6 months

VAX 11/780s - Masscomp - Valid equipment available

by kapteynr＠cboe.com

Finally -- a nice haul in my area. BUT I WAS ON VACATION !!!! Is any of this still available ? It ALL looks interesting to me. I am in Chicago and I have a truck, and a lot of storage space (with loading dock). -Rob -----Original Message----- From: Jon Auringer [SMTP:auringer@tds.net] Sent: Tuesday, January 08, 2002 6:53 AM To: Classic Computer Mailing List Subject: VAX 11/780s - Masscomp - Valid equipment available Hello all, Along with the Astronautics ZS-1 machines I posted about earlier, we have some other equipment available. I have someone interested in one of the 11/780 machines and possible others. As with the ZS-1 machines, the time frame isn't very long. Again, we are closing this facility and the equipment will be scrapped if not rescued. 1 DEC 11/780 (3 wide cabinet) currently up and running 4.2 BSD 3rd cabinet has a Ven-tel plugin modem rack w/~10 modems 1 rack containing 4 Fujitsu Eagle drives (one drive is off-line due to increasing errors) 1 Fujitsu 9-track tape drive in 2 wide cabinet (not quite as tall as the VAX cabinet)(This is a nice auto loading drive, there is a second one available with two drives from a non-VAX system) 1 DEC TE16 9-track tape drive (1 wide cabinet) 1 Fujitsu line printer 1 DECWRITER III printing terminal as console 1 DEC 11/780 (3 wide cabinet) currently down but was running fine when turned off (VMS) 3 DEC RP07 drives (each the size of a washing machine on steroids!) 1 DEC TU78 9-track tape drive 1 Scicards design station (This is a dedicated color graphics terminal used for printed circuit board (PCB) layout) I am told the tube was a little on the fuzzy side. 1 Benson photo plotter (we used this exclusively to print out PCB artwork for checking) 1 Dataproducts line printer 1 DECWRITER III printing terminal as console 3 Valid Systems m68k based Multibus systems. Each system has several dedicated mono graphics cards to drive multiple design stations. Each system is in a half-height rack which contains the Multibus rack, an 8" Fujitsu fixed disk drive and the slot loading 9-track tape drive. I am unsure of the status of these systems. I believe they were running when shut down, but I have doubts about the drives. 6 or more of the Valid Scaldstation design stations. Each includes a table with built-in digitizer and a 19" green monochrome graphics monitor. These systems were used primarily for schematic capture, but ran a full blown UNIX, so I always enjoyed reading news on the "big screen". :) 1 Masscomp m68k based system This system is also Multibus based and resides in a pair of 5' high racks. One rack contains the multibus chassis and a pair of Fujitsu drives. The second rack houses the 9-track tape drive and a third 8" Fujitsu drive. This machine was only lightly used when I signed on in 1989, and shut down shortly thereafter. I have gotten it up and running RTU on its ST-506 boot drive, but haven't managed to get the Fujitsus online. 7 Masscomp MC-500 deskside chassis These are also Multibus based m68k systems. These run the same OS as systems above. They have an internal 5-1/4" floppy and ST-506 fixed drive. There are a bunch of the monochrome graphics tubes that go along with these units. Actually, it appears like each chassis is designed to drive a pair of the graphics terminals. I have one of these boxes that I did a clean install of the RTU OS. The other 6 are in varying states of repair. I think there are enough bits to assemble at least 3 more complete systems. 2 DEC MicroVax II in a 19" There is also a rack mounted chassis with a pair of SMD drives. Each of the MVII has a SMD controller card. Both of the boot drives are dead and I don't have a way to format replacements. I would like to hang on to these if I can manage to get them home without doing myself harm. 1 Tek 4014-1 graphics terminal w/hard copy unit. The terminal works fine, but I haven't had a chance to test the hard copy unit. I would like to hang on to this unit, but moving it is definately a two person and a truck kind of thing. So I may have to let it go. :( ? StorageTek 9-Track drives. 110V operation. How many of these I have depends on the fate of the ZS-1 machines. I have a couple now, and will have several more if the ZS machines are scrapped. Large quantities of documentation. Over a dozen UNIX programmers manuals in metal desktop racks. Complete documentation sets for VMS, gray and orange binders. I have a box with complete unopened docs for a later version (don't remember off-hand which version) of VMS than we had ever installed. Documentation for several revisions of SunOS4. If I were to walk through the building, I could easily double this list. Basically we have just about everything! Thanks for listening, Jon Jon Auringer auringer(a)tds.net

22 years, 6 months

OT? Apple Stylewriter problems (longish)

by pete＠dunnington.u-net.com

On Jan 14, 19:16, Tony Duell wrote: > Read that as 2SB1243 -- which is not in 'Towers International Transistor > Selector'. No, but it's in my Japanese transistor book (I can't tell you the proper title because it's in Japanese :-)) Yes, it's a PNP power trannie, in an ATV package, which is a bit like a TO220 but without the metal tab. It has a beveled edge on the front top, instead of a metal tab on the back. Vcbo -60V Vceo -50V Ic(max) -3A Pc 1W Icbo -10microA Vcb -40V hFE min 56 max 390 at Vce=-3V Ic -0.5A Vce(sat) -1V Vbe(sat) -1.5V Ft 100MHz Pin order is ECB (opposite of the common TO220). Near equivalent 2SD1864. > I am pretty sure 2SB numbers are 'power' PNP transistors. In which case > I'd expect the emitter to go to a +ve supply line and the collector to go > to the printhead pin. If it's a TO220 package, then it's a good bet the > pinout is : > > > ------------- > | | |------------- emitter > | O | |------------- collector > | | |------------- base > ------------- -- Pete Peter Turnbull Network Manager University of York

22 years, 6 months

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test-drb January 2002