test-drb April 1999

test-drb@ccmp.vtda.org

170 participants
1190 discussions

by Philip.Belben＠powertech.co.uk

Dear All I am thinking of renting a building in which to store my computer collection, together with that of a friend who has gone to Canada [Bob Manners, for P850UG people]. The building is very simply constructed - single brick walls and sheet asbestos roof - and currently has no supply of electricity or gas, but appears fairly dry (at least at present). Do people on either of the two lists have suggestions for: What precautions should I take in storing computers here? Do I need to insulate / heat the building? Should I install a dehumidifier (I think I can get hold of one)? Do I need (for example) to wrap each computer up in plastic with a packet of silica gel? The rent is very cheap - L2 (about $3.30) per square foot per year, and the building is only 10 min walk from my house. With luck, this will mean that I shall soon have a house with room for me as well as my junk... Philip. <><><><><><><><><><><><><><> Philip Belben <><><><><><><><><><><><><><> Bloedem Volke unverstaendlich treiben wir des Lebens Spiel. Grade das, was unabwendlich fruchtet unserm Spott als Ziel. Magst es Kinder-Rache nennen an des Daseins tiefem Ernst; Wirst das Leben besser kennen, wenn du uns verstehen lernst. Poem by Christian Morgenstern - Message by Philip.Belben(a)powertech.co.uk ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. **********************************************************************

25 years, 2 months

Compupro and DG question

by rigdonj＠intellistar.net

Went scrounging again today. Picked up some good HP stuff. Also found a Compupro 8/16 chassis with no cards or top cover. Also found a Compupro Hard Drive Subsystem chassis. It had one 5 1/4" and one 8" floppy drive. The hard drive and top cover were gone. Is the 8/16 an S-100 chassis? Anyone need this stuff bad enough to pay shipping and a scalper's price for it? Also found a DG hard drive. Looks like a 14" in a clear cover. I think the model number was 3462. Looks too heavy to ship unless someone REALLY wants it. Joe

25 years, 2 months

stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies)

by edick＠idcomm.com

I knew somebody woudl come up with a good example. That 6809 code is probably the closest thing I've seen in a micro. The 8051 uses a similar approach, pointing to the table with the datapointer and uses the accumulator as an offset. It does make it a bit awkward passing a parameter in the accumulator, though. In this case, the accumulator is occupied by what's really the only value you'd want to pass anyway under the circumstances. They (DEC) did make the uVax-II as a chipset for interfacing to their BI-bus, I believe, so that might qualify as well. The DEC chipset probably didn't sell for what a 6809 costs, even the faster part, and certainly not the $0.86 I last saw on the 4MHz Rockwell 65C02. The 6502 and its scions save a clock tick every time they loaded an address because the indexing or whatever arithmetic could be done on the low byte while the high byte was being fetched, leaving the carry set or cleared as was required, for the arithmetic on the next byte as was appropriate. Note that the carry was generally irrelevant, as most instructions requiring indexing simply wrapped the PC, but not in all cases. I thing indexed mode addressing was a case where an index could cross a page boundary. The MOT processors could often do the same thing, but they needed to add a clock tick to order the bytes and another to propagate the carry if appropriate (I think). It wasn't that sort of hair-splitting I was after, but rather, a contrast between the simple, elegant instruction set of one processor, versus the not-so elegant instruction set of "the other" meaning the intel/zilog clan. I'm not surprised that it was in the 6809 that this instruction came up. The 6809 showed lots of promise at first, but once it was in hand, one clearly could see that it would be MUCH easier going with the MC68008 if one had to use an 8-bit bus. I never had the opportunity to write in a high-level language for the 6809, but I was told it should have been quite easy to write a high-quality efficient compiler for it because of its repertioire of instructions and addressing modes. I turned out literally tens of thousands of lines of assembler code for it and never used this feature, though. It's likely most of my code would have run on a 6802 or 6803 just as easily. Dick -----Original Message----- From: Sean 'Captain Napalm' Conner <spc(a)armigeron.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 10, 1999 1:27 PM Subject: Re: stepping machanism of Apple Disk ][ drive (was Re: Heatkit 51/4 floppies) >It was thus said that the Great Richard Erlacher once stated: >> >> At the risk of becoming the resident infidel . . . >> >> The 6502, particularly in its later incarnation by Rockwell embodied the >> cleverness fostered by its earlier versions and the non-Intel family of >> processors. How the elegance of their instruction set became lost is a >> mystery to me. > > I've never been a real fan of the 6502, it seemingly geared more towards >embedded systems than for a general purpose computer. But that's just me >8-) > >> On a 65C02 from Rockwell (making the distinction because there were several >> CMOS 6502's, all slightly different) you load the input value into an index >> register and then jump, indexed indirect, to the routine which is >> appropriate for that pattern of inputs. This requires, then, that you have >> a table with 256 bytes, more correctly 128 words, with each word the >> address of the routine which is used to process the left-justified ASCII >> data. >> >> This is tremendously fast! It requires no STACK, and it requires only two >> instructions. Another way of doing this involves building a stack frame and >> loading the return address with a value looked up in a table, then executing >> a return. This can be done with any number of processors. On a Z-80 you >> can jmp HL, and I'm sure there are other neat ways of doing this simple >> thing. I've never seen anything more elegant than that simplistic sequence >> on the 65C02. How the MOTOROLA people let this go by the wayside in the >> design of their 6809, 6801, 68K family, and countless others puzzles me. >> I've not made an extensive study of other processors, but I have looked at a >> few. The only processor I've used which has a similar mechanism at its >> disposal is the 8051 core. It has a data register which can be used as an >> offset for a jump instruction. > > If I understand the problem correctly, then what you want can be done on >the 6809 as two instructions as well (okay, three, but the first one is only >there for setup): > > LDX #JMPTAB > MAIN: LDA UART > JMP [A,X] > > > As long as X is unchanged, your overhead is two instructions. Also, if >you want to use X for something else, you still have Y or U for use as well >(okay, you can use S, but then it gets a bit harder 8-) > > But if you want elegance, go with the VAX---one statement: > > caseb uart,0,255 > jmptab: .word c00 - jmptab > .word c01 - jmptab > > ; ... > > .word cff - jmptab > > And with this, you don't even have to jury rig a special UART. > > In fact, the VAX is about as elegant as they come---you have 16 general >purpose registers and the PC is one of them (R15). Not only that, but all >addressing modes work on all instructions---it's very regular and with some >practice you can probably end up reading hex dumps directly. It's a very >nice assembly language. > >> Now, I doubt that anything that simple can be used to discriminate between >> what's "best" and what's not, but it's for certain that it's a nice feature >> not available on the 6809. I used the 6809 extensively while I was in the >> aerospace industry, and found it fairly friendly. BUT, it still is >> relatively slow, as compared with processors of the same generation from >> sources clever enough to arrange the bytes the other way around in memory so >> you didn't have to fetch and the discard a high byte when there wasn't one. >> Fortunately, many tasks don't require a really fast processor. > > I don't follow. You either care about a 16-bit quantity, or you don't, >but I may be biased---my first CPU was a 6809 and when I switched to the >Intel x86 architecture, I didn't like the little endianess of it at all, but >I never found the bigendianess to be a real problem. > > -spc (Then there's the ARM ... ) > >

25 years, 2 months

Big Iron

by mbg＠world.std.com

I've got the pictures of the KS10 systems up on my web page... For anyone interested... http://world.std.com/~mbg/home_systems.html#ks10s to read a little about it.... Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+

25 years, 2 months

DG AViion stuff

by geoffrob＠stmarks.pp.catholic.edu.au

Someone wanted stuff for the M88K Data General Aviion's running DGUX. There is a fair bit at this site.. http://ftp.avlib.clemson.edu/avlib/pub/88k/ Hope this helps Cheers Geoff Roberts Computer Systems Manager Saint Mark's College Port Pirie, South Australia. Email: geoffrob(a)stmarks.pp.catholic.edu.au ICQ #: 1970476 Phone: 61-8-8633-8834 Mobile: 61-411-623-978 Fax: 61-8-8633-0104

25 years, 2 months

Trenton Computer Festivalt

by museum＠techniche.com

Can either of you supply any details? Date? Times? Specific location? >> I'm thinking about attending the upcoming Trenton Computer Festival. >> Unfortunately, if I do go, I won't be able to make it until Sunday. Any >> opinions on whether or not the second day of the TCF is worth a two and a >> half hour drive? >> >> Thanks. >> >> Tom Owad > >In the old days it was bargain and dumpster dive day. >TCF was a lot like what the VCF sounds like. (Except with a mix of some of >the classic stuff with some of the newer computers.) > >PDP 8's, and PDP11's as well as S100 stuff was common. Now there's some >Sun, Vax, HP Unix stuff, some older S100, H89, H8. Some CP/M (rare) >some Macintosh and Apple II/III... But it's becoming more and more >a Windows and PC kind of show. > >I don't know what it'll be like this year with Ken Gordon running the show >on contract (but I fear the worst). > >Bill >--- > bpechter@shell.monmouth.com|pechter@pechter.dyndns.org > Three things never anger: First, the one who runs your DEC, > The one who does Field Service and the one who signs your check. >

25 years, 2 months

TRW Swap & Vintage CompuCrawl(tm)

by jpl15＠netcom.com

A Reminder: Saturday, April 24th.. for all listmembers who will be in the Southern California area - The TRW Ham Radio and Electronics Swap Meet will be heald on the morning of the 24th, from 7:30 to 11:30, in the southernmost parking lots of the TRW plant in El Segundo, CA. From the 405 (San Diego) Freeway, take the Rosecrans exit west, go west on Rosecrans about 1 mile to the intersection of Aviation, then left at Aviation (under the Metrolink bridge)... proceed south on Aviation 1/2 mile, the swapmeet will be in the parking lots on the right, before Marine avenue. After the swapmeet, there will be the customary CoCo's Brunch 'n Brag, from noonish until one-ish. THEN: I will host a Vintage Computer Open House CompuCrawl. Listmembers and interested persons are invited to my place to look at / play with / make scurrilous jokes about my motley collection. I have four DEC machines running and a Pr1me 2550, as well as various micros, etc. This event will last until whenever Saturday night. Persons needing advance directions to my residence are encouraged to e-mail for directions. I *do* live in a rural area so directions are recomended. I believe some persons from outside the SoCal area expressed interest in showing up, so e-mail me privately for contact info. Cheerz John

25 years, 2 months

Sigh. Bringing up a PDP-8/M

by allisonp＠world.std.com

<OK... First thing is to clean out the backplane in the 8/m. Use a vacuum <cleaner to remove loose dust and then squirt isopropyl alcohol <(propan-2-ol) into the connectors. Dry it well before powering it up. Also make sure there are no shorts under the backplane to the outer case from foreign objest like screws. <Then, if it still doesn't halt, check the power supply. I can't remember <what the power good line will make the CPU do if it's in the wrong state, <but I don't think it forces the CPU to the RUN state (unlike the 11/45...) It does have power fail and if it's in the "wrong" state the machine it halted. Look for obvious stuff, shorted wires or other conductors (even on boards) and leads floating loose or misconnected. CHECK all three voltages because if any are missing it will do nothing intelligible. Allison

25 years, 2 months

VERY OT: Win'98 splash screen

by fpp＠concentric.net

>Me, too, but you don't know my dad... >He has his computer in the living room, with the screen facing the window, >and he says that he wants it to look nice when it's booting (don't_ask)... >I think he deleted the spare one, too. I did a search, and can't find it >anywhere. Either the computer didn't come with a copy of the CD on the HD, >or my dad deleted the copy, because I can't find that, either. >I told him he'd be better off to just put DOS back on the thing.... If he did not get the Windows CD then perhaps you have a bootleg copy of Windows. All new PC's have a CD copy and Microsoft certificate of authenticity.

25 years, 2 months

Restoration of an 11/34a

by mbg＠world.std.com

>You did remember to cut the NPG jumper on the slot that you stuck the >RL11 in, I hope... Thanks... I did forget (I've done mostly Qbus for quite awhile... so the UNIBUS specific stuff may slip my mind for a bit) >That's the most common 11/34 problem, assuming you're using an M9302 >terminator. You have a grant open somewhere (either you're missing an >continuity card or you've got an NPG jumper missing). THe M9302 then >asserts SACK, the CPU tries to remove the asserted grant line but can't, >and it locks up. Aha... right... I'll have to check the backplane... there were a number of boards in it, some were probably DMA devices... (as I said, it may take a little time for it to come back to me...) Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg | +--------------------------------+-------------------------------------+

25 years, 2 months

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test-drb April 1999