test-drb August 2001

test-drb@ccmp.vtda.org

295 participants
726 discussions

by mcguire＠neurotica.com

On August 19, Chuck McManis wrote: > Would I be correct in assuming that a MXV11 and a KDF11 would be the > minimum PDP-11/23 that will talk "ODT" ? I would say yes. A quad-width 11/23 board (KDF11-B) comes to mind with its onboard console SLU, but then you'e need a memory board, so...still two boards. -Dave -- Dave McGuire Laurel, MD

23 years, 4 months

SemiOT: Mourning for Classic Computing

by dhquebbeman＠theestopinalgroup.com

> I'm talking mainly about kids, but anyone who is ready to be a programmer > can be taught. But not everyone is a programmer. Those that get it are > programmers. Those that don't are users, and should remain that. ^^^^^ More like lusers.... ;-) -dq

23 years, 4 months

Who reads their email the most Classically?

by dhquebbeman＠theestopinalgroup.com

> Master of all that Sucks skrev: > > >Actually Iggy, your preferences are more irrelevant to me. Chuck's always > >been polite to me, and I respect that. Chuck *is* a righteous dude... > It amazes me how people who work with computers for a living have failed to > grasp the most basic concepts of netiquette. I'm with you, Iggy, as to a preferred quoting mode. But while I used to think of it as an netiquette issue, I now see it as a Ford vs. Chevy, Coke vs. Pepsi, Poached vs. Sunny-Side-Up... type of thing. Me, I drive Audis, drink iced tea, and eschew eggs except when disguised as cakes, Mayonaisse, etc. -dq

23 years, 4 months

tape drive question

by fmc＠reanimators.org

jarkko.teppo(a)er-grp.com wrote: > Hmm, first time I read about a 7976, care to tell more :-)? Back about 1981, HP was complacent about half-inch tape drives -- they had their 7970E design and it was a real workhorse. But it was at best a 9-track 1600 bpi drive, and customers' data storage and backup needs were getting a bit large for that -- the site I worked at back then was dealing with a 20-tape full backup, and at 13 minutes to write each tape that meant over four hours of downtime. (And this was in the days when one bad tape would make STORE give up, and we had plenty of Memorex MRX IV tapes.) So HP did a deal with Storage Technology Corporation (STC) to get an HP-IB-attached 6250 BPI tape drive to market quickly, and this device was sold as the HP 7976 starting in about 1983. We bought one back then. Every six weeks it would blow a transistor on its servo board, we would place a service call, and some lucky HP CE would come out, replace the servo board, and stand there for a couple hours with the drive open and a tape loop mounted, twiddling some adjustments in the drive while watching a scope on the floor. The first guy who did this was on the tall side and was out of the office the next day with back trouble. The second time around they sent the new guy who found he was the right height to do this standing upright. We saw him every time thereafter. Being an STC drive, it has vacuum columns. Part of the CE toolkit for the thing was a vacuum gauge which was referred to by one of the CEs as a "suck and blow meter", in a way which made it clear that from his point of view these were *the* two operational modes of the drive. The vacuum columns are lined with little glass beads that are glued to the sides of the columns. Alcohol is a solvent for this glue, so make sure you use Freon TF to clean the drive! There's a small board set in its own cage under the drive. This is the part that provides the HP-IB interface. Some numb-nuts spec'd the cage to be a little bit too small, so another tool in the CE toolkit is a hammer to force the boards into place. It was picky about tapes too (especially compared to the 7970Es). HP recommended their own tapes, which I think were re-badged Graham Epoch 480s. We wanted 3M Black Watch. Our purchasing department was of the opinion that tape was tape, which is how we got Memorex MRX IV tapes, and later they got us a box of BASF Endura tapes that really made us think the Memorex tapes were good. Anyway, we continued to have problems, and there was a finger-pointing exercise in which HP told us many of our tapes (by this point we had got the purchasing folks to get us Black Watch) had been scored. We pointed out that these tapes (being for system backups) were used exclusively on one drive, the 7976. HP countered by saying we must not be cleaning the drive properly. There was some acrimony which ended up with HP replacing our tapes and us buying a 7978 to replace the 7976. Believe it or not, this made everyone happy: things started working for us, and HP didn't need to make near as many service calls out to our site. So my take on the 7976 is that somebody should save one, that others may learn from its mistakes. -Frank McConnell

23 years, 4 months

tape drive question

by fmc＠reanimators.org

ojw(a)dircon.co.uk wrote: > Hi. Having recently been the happy recipient of an HP 7978 tape drive I have > set about the task of finding new blank tapes for it. Not too difficult > until faced with the embarrassing question of whether my tapes need to be > Wright Line seal or Easy Load (Auto Load ?). The 7978 doesn't do anything with the autoload seals so you will have to remove and replace them manually. Wright Line or similar seal is probably easier to handle manually and somewhat less brittle plastic too. The 7976 can handle autoload seals if present, but this doesn't really make up for the rest of the drive. -Frank McConnell

23 years, 4 months

FREE: two RX01 dual floppy drive units

by mrbill＠mrbill.net

I've got two RX01s, free for pickup in Austin, TX. Email if interested. Bill -- Bill Bradford mrbill(a)mrbill.net Austin, TX

23 years, 4 months

SPARCStations anyone?

by cmcmanis＠mcmanis.com

Is anyone on the list interested in SPARCStation 1's ? --Chuck

23 years, 4 months

PDP-11/23 question

by cmcmanis＠mcmanis.com

Would I be correct in assuming that a MXV11 and a KDF11 would be the minimum PDP-11/23 that will talk "ODT" ? --Chuck

23 years, 4 months

Altair32 Posted

by rcini＠optonline.net

Hello, all: I'm posting working code and pre-built binary, along with a binary image of Altair BASIC 3.2. It works very well. I have no way yet to guage relative speed to a real Altair, but it seems pretty responsive. What I'd like to do is ask an Altair owner on this list to create some sort of benchmark program and run it on his real Altair. Then, I'll run it on the Altair32 and that'll give me a basis for improving the speed of the emulator. Thanks again and enjoy. Rich Rich Cini Collector of classic computers Build Master for the Altair32 Emulation Project Web site: http://highgate.comm.sfu.ca/~rcini/classiccmp/ /************************************************************/

23 years, 4 months

Identify this mystery Q-Bus board!

by zaft＠azstarnet.com

I have an unidentified Q-Bus board that I'm hoping someone will recognize. it's a quad-height (i.e. full-size) board. On the component side is says "RELIABILITY ASSOCIATES" and (c) 1987 and "TIME SLOT CONTROLLER". It has two 40-pin headers and a 20-pin header and two pushbutton switches. Chipwise, it's got a 68000RC10, a couple of 68450s, three MK68564s, and a 74S409N, all socketed, and a host of PALs and MSI/SSI chips. Anybody know what this is? Also does anyone have data sheets for 74S409? Gordon Gordon Zaft zaft(a)azstarnet.com

23 years, 4 months

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test-drb August 2001