test-drb March 2007

test-drb@ccmp.vtda.org

239 participants
488 discussions

by dm561＠torfree.net

From: Fred Cisin <cisin at xenosoft.com> Subject: Re: place your bets To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Message-ID: <20070303100354.K76450 at shell.lmi.net> Content-Type: TEXT/PLAIN; charset=US-ASCII On Sat, 3 Mar 2007, Chris M wrote: > For fun, how's about we create a list of units that > had 8" drives. Off the top of my head: <snippage> Cromemco CDOS Cromemco Z2 (Micah) .... There are a lot more. .......... ------------------------------ AFAIK 8" drives for the Z2 were all third-party; however, the System 3 and 300 were stock 8" drive systems, first the dual Persci's and later Tandon TM 848's. mike

17 years, 1 month

B.M.S. tape format

by ard＠p850ug1.demon.co.uk

This is on-topic if you think the HP9830 is a computer :-) I'v been thinking about the internal cassette tape drive of that machine, with particular refeerence to being able to read/write the tapes in some other machine. By chance I was looking at the technical manual for the Racal Thermionic (the company name, it doesn't use valves!) Digideck P72. This unit has obvious similarites to internal tape drive on the HP9830, in fact some mechanical parts will interchange between the 2 units. Anyway, it appears the data format is very similar too. There are 2 tracks on the tape. A pules on one track is a '0'. A pulse on the other track is a '1'. And a pules on both tracks together is a marker. The format of a byte on the taoe is M b b b b f b b b b M Where 'M' is a marker (and both markers are part of a given byte, by default, therefrore, there are 2 markers between the data bits of adjacent bytes on the tape), 'b' is a bit of the data byte and 'f' is a flag bit. The flag bit, being in the middle, appears in the same position in the serial-parallel conversion shift register no matter wheter the tape is moving forwards or backwards. I think HP used it to identify the bytes in the fiule header or something. It's not chear whether HP record 2 markers between each byte, or just one. But the Digideck can do either. Anyway, the Racal manual refers to this as 'B.M.S. format'. Has anyone heard of this? A google search doesn't find anyhting that looks relevant. -tony

17 years, 1 month

ASR33 Partsbook and Facit 4070 manual

by ard＠p850ug1.demon.co.uk

>From time to time I get asked about the Teletype ASR33 Parts List (much harder to find than the other 2 volumes of the maintenance manual) and the service documentation for the Facit 4070 paper tape punch (which was used by just about all computer manuafacturers in the early 1970s...) I was poking around on www.hpmuseum.net and _both_ are on that site. The trick is that : HP2752A == ASR33 and HP2895A == Facit 4070 with HP modifications (an extra interface PCB, etc) In the fromer case the 3 volumes of the Teletype docs are available to download separately (the HP manual just gives the modifications to make it HP-compatible, and the schematics), tin the latter case there is one manual, most of which is the Facit service docs and parts lists. -tony

17 years, 1 month

FW: Re: old rare diskdrives?

by aek＠bitsavers.org

> Al Kossow wrote: > > > I have see some disk drives on your homepage and want to ask you if > > > sale the magnetic and coils from the old diskdrives? > > > > no > > Hear hear!! > > Peace... Sridhar > -- html links to eBay auctions clipped. "magnetic and coils from the old diskdrives" aren't what you'll find in commodity discs today. I assume he's asking about linear motors >from large drives, circa '85 and earlier, which have mostly gone into landfills. A linear motor from an early 80's drive is on the order of 4" x 8" with a pretty massive casting.

17 years, 1 month

place your bets

by ajp166＠bellatlantic.net

> >Subject: Re: place your bets > From: Fred Cisin <cisin at xenosoft.com> > Date: Sat, 03 Mar 2007 14:08:57 -0800 (PST) > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Are there ANY 30 year old computer companies that didn't? >(not counting "consumer electronics" companies :) > Apple! While there were add on 8" drives Apple started with 5.25. I'm sure there are others. Allison

17 years, 1 month

Geek Art Show

by jrkeys＠concentric.net

A local Art museum here in the Houston area is putting on a Geek Art showing in August and connected me for ideas and possible help. Is there anyone on the list living in this area that may have some computer generated art or any art that would be willing to loan out for the show? Contact me off list if you like to help out. Any suggests from the list on what you would like to see in a geek art show let me know also. Thanks for your time, John Keys

17 years, 1 month

OT: How do I flash an ATI Rage 128 GL for a PC?

by woyciesjes＠sbcglobal.net

Apologies for being off-topic. Please reply to me directly, and not the list. I've got an ATI Rage 128 GL 16MB PCI video card from a B&W Mac G3. I put it in my Dell Precision 530 workstation, CentOS 4.4 Linux recognizes it, but no video comes out. Not even when I tell the BIOS to use that instead of the AGP card. Looks like I need to change the firmware from the Mac version to PC. Searching on Google so far hasn't turned up anything. Anybody know where to look? Or does anyone have a comparable video card for trade/gift? -- --- Dave Woyciesjes --- ICQ# 905818 --- AIM - woyciesjes "...Talking to you is like clapping with one hand." Anthrax, "Caught in a mosh"

17 years, 1 month

HP 21MX/F and OS choices (was Lookee what I just got!)

by steerex＠mindspring.com

With that work done, it may be practical to boot your HP over a serial port at a reasonable speed, but loading a large ABS file this way can take a very long time (as things are). I generally don't recommend the serial boot method due to its poor performance. Then again, I think its nothing to throw together a PIC and some I2C eeprom and build little paper tape reader and punch emulators, and I can burn copies of any loader rom you wish. I found that serial booting the system to be the easiest way to get started. I don't recall which one but, one of the loader ROMS will work with the "high speed serial" card and read data off a serial link. There's no handshaking or error correction but, with a short RS232 link, passing data is not a problem. The ABS data format does provide checksum error detection so data errors will be detected. On many occasions, I have loaded HPBASIC and other programs over a serial link with absolutely no problem. The advantage to the serial link is that the only hardware required is a RS232 serial cable. Admittedly, it is not as fast as a parallel link but, who cares ;-) I had to write a PERL script to format the data before passing it to the 1000 but, that was fairly trivial. SeeYa, SteveRob

17 years, 1 month

Abandoned Prime looking for new home (UK)

by james＠machineroom.info

Hi all, this is probably the shortest time I've owned a machine. Bought just a few months ago as a "project" I now have it to offer again. I simply don't have the skill to get this running. I've also got too many other projects :) It's ex Salford Uni Prime 2550. Comes with 2 disk drives, 1 tape drive, 3 boxes of manuals, 2 boxes of tapes, 4 5.25" floppy drives and a bunch of terminal lines. Pictures (including all the manual covers) are here http://www.flickr.com/photos/17208732 at N00/ Located in Southampton near M27 J7. It's yours for the taking. I'd like it to go to a genuine collector but will consider any and all interest! I can hang on to it for a few weeks but it's just taking up valuable space right now. If there's no interest in the entire system then I may part out boards, manuals, etc. As I understand it when I bought this it had sat for a year unused. Previous to that it had sat for a few years in a garage and been used occasionally and prior to that had been in the hands of the chap who rescued it from Salford. When I received it I had problems getting anything sensible on the terminal then things went downhill and I discovered the main 5V PSU had failed. I tried replacing that with an external 200A unit borrowed from my Cray EL but hadn't considered how many other signals are generated by the power supply. (MAN070 is available on bitsavers but this only covers the older Prime models - the power supply signals look the same but the VCP is very different). The ? 12 and +16 are all OK. I tried faking some of the power good signals and checked others (50Hz clock, etc). I even found one signal had broken on the backplane and have repaired that. Unfortunately without the manual for this specific model I'm stuck. In it's current condition it just sits with all front panel lights on and nothing on the console. CPU: As I say, the 5V supply has failed. I've patched several lines (the power good signals) inside the supply. I've had all the boards out, cleaned the connectors and vacumed the boards and case. I can include an 80A 5V supply if it's of any use to you (I'd hope 80A is sufficient. The 200A unit I was using is now back with the Cray!!) Disk drives: I found that the bolts holding the disk units in the casings were missing (a bag of "spares" was supplied which included the bolts and rubber mountings). I replaced the bolts before powering up, thankfully! One of the disk units powers up and spins. The other doesn't power at all. I removed all the dust too whilst the drives were out. Tape drive: Powers up and front panel buttons seem to "do stuff" but can't test any further. Tapes: These are all externally clean but a lot of the casings have cracked. You'll need some experience with 9 tracks to read these I expect. Documentation: There's a lot of very tidy manuals and also quite a few loose manuals in ring binders. There's also about 10 pocket guides. What is nice is the collection of history - there's administrator logs, service requests, etc. Floppy drives: I'm told the two original Prime badged units have failed. There's a couple of more modern replacements (and a handful of floppies) included - one of these should work! Without a working system I obviously can't test anything. Therefore, you should consider this as a source of spares or possible repair if you have the skill and/or manuals. I'm around most weekends for collection and can obviously give a hand loading. A standard SWB Transit does the job nicely. So come on, give the Prime a new home. Please :) James

17 years, 1 month

Nine track tape BOT sensing foil

by ian_primus＠yahoo.com

After a recent fight with some Cipher tape drives, trying to boot a system, I managed to badly mangle the leader of my boot tape. Now, rewriting the tape isn't a problem, but fixing the tape is. I can cut off the mangled leader, but then there won't be enough tape left before the BOT marker. The BOT on a nine track is just a hunk of sensing foil, just like I remember from trying to repair eight track tapes (BTW, tinfoil and double sided tape _doesn't_ work on eight tracks). Rat Shack no longer sells sensing foil, surprise, surprise - so, does anyone know of a currently available solution? That metal duct work tape perhaps? I don't want to use anything that might risk damage to the heads though. Any ideas? -Ian

17 years, 1 month

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test-drb March 2007