test-drb August 2007

test-drb@ccmp.vtda.org

221 participants
459 discussions

Fwd: [sdiy] Wanted: Multibus (late 70s microprocessor bus) extender card

by rtellason＠verizon.net

Can anybody here help this guy out? ---------- Forwarded Message ---------- Subject: [sdiy] Wanted: Multibus (late 70s microprocessor bus) extender card Date: Tuesday 31 July 2007 17:30 From: "Steve Lenham" <lenham at clara.co.uk> To: "SDIY list" <synth-diy at dropmix.xs4all.nl> Hi, Does anyone happen to have spare, or can anyone point me in the direction of an inexpensive source for, an extender card for Multibus (the late 70s microprocessor bus standard)? I know that Digikey and Mouser list them new, but they are around $120 each. I'm working on a Lexicon 224 reverb unit (a fascinating device), which uses a Multibus backplane and eight plug-in cards. I need to be able to work on these cards with them still attached to the bus - hence the need for an extender. Any pointers would be much appreciated. I'm in the UK, but am happy to import. Cheers, Steve L. _______________________________________________ Synth-diy mailing list Synth-diy at dropmix.xs4all.nl http://dropmix.xs4all.nl/mailman/listinfo/synth-diy ------------------------------------------------------- -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

16 years, 8 months

cctalk Digest, Vol 48, Issue 2

by mtapley＠swri.edu

At 18:38 01-Aug, Jerry wrote: >Hi, > >I'm trying to get a MONO Cube I have here back to >a complete box. Good going! >Missing is the >- Floppy Drive 2.88 Sony and Bezel Drive is not so critical, many of them didn't have that. But having one is pretty nice when it comes time to boot the install CD. A Bezel is a *big* deal because of cooling airflow, I found out. My floppy drive looks out through a non-bezel aperture, which I keep covered with tape most of the time so cooling air doesn't escape that way. >- mounting Bracket for the Drives ??? The large piece > above the Power Supply is there. I would guess it had > something to hold the 3 1/2 drives. The what? ;-) NeXT supplied 5.25" hard drives, which just fit between the walls and mount with bolts through the bolt-holes in the side walls. You are more or less on your own for mounting a 3.5" drive in a cube. Mine >- no Optical drive or cover. Not Sure it had one ?? Many of them didn't have an optical drive, and almost *none* of them now have a functioning optical. Dust is one culprit, but there seems to be something (I have not really investigated) that kills them all over time. The optical is a great novelty and I really wish it had caught on, but it's not too useful today. >- no expansion slot covers. Rear cover is there. I think these would be less critical for cooling, but still good to have. >- mouse is missing Depending on the model, you may be able to use an ADB mouse (though will miss the other button). Do you have an ADB keyboard (distinguished by the "control" bar below the space bar)? >This is a 68040 25 built is 1991 > >Looking into the 2.88 floppy it looks like there was >no standard for the connection on the different makes. >So either I have to use a sony or make a adapter Sony, I think. I'm not aware of any substitutes. I can endorse Randy Rencsok, reachable through: http://www.channelu.com/Turbo/index.html as a parts supplier. There are also a fair number of downloads on his site which may be of use to you, as well as pictures of some of the missing parts. I also note the existence of http://www.blackholeinc.com/ but have not done business with Rob Blessin, though he's been pretty supportive in general of the NeXT community. >Thanks, Jerry > >Jerry Wright >JLC inc Good Luck! -- - Mark, 210-379-4635 ----------------------------------------------------------------------- Large Asteroids headed toward planets inhabited by beings that don't have technology adequate to stop them: Think of it as Evolution in Fast-Forward.

16 years, 8 months

UK VCF?

by silvercreekvalley＠yahoo.com

I'd be delighted to attend a UK VCF if there was one or something similar. At a push I would be happy to demo a few interesting machines :) Ian ____________________________________________________________________________________ Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow

16 years, 8 months

UK VCF?

by silvercreekvalley＠yahoo.com

I'd be interested too. For venues, what kind of size place would be needed? I've vistited several fairly active shows, some of which could be called somewhat vintage - eg the RiscOS shows. These are often held in sports halls or similar. There is also the retro show North, which is more classic gaming consoles. (www.retronorth.co.uk) Some others in the past included the 'all formats computer fairs', which often combined commercial sellers/items for sale with stands from clubs. A bit like the VCF in Mountain View. Ian ____________________________________________________________________________________ Pinpoint customers who are looking for what you sell. http://searchmarketing.yahoo.com/

16 years, 8 months

Imagedisk 1.17

by ajp166＠bellatlantic.net

> >Subject: Re: Imagedisk 1.17 > From: "Dave Dunfield" <dave06a at dunfield.com> > Date: Fri, 27 Jul 2007 07:11:40 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >> Lately I've found a very nasty bugs in IMD 1.16 (at least with a secondary >> FDC, tested on two different machines of different speed with different >> FDC). Reading disks is mostly fine, but writing to a drive connected to a >> secondary FDC doesn't work reliably. The problem is that the drive won't >> step properly, i.e. sometimes it misses a step pulse which makes the >> written disk unusable. The same problem occurs e.g. with the clean head >> routine. I had a look on your source code and I think it's a timing >> issue. I've inserted a small delay ('delay(55);') into the seek routine >> (between line 998 and line 999 in version 1.16) and this solved all the >> problem. I think that the seek routine is called too early after having >> sent the previous command to the FDC although it shouldn't matter because >> wrfdc officially waits for the FDC to be ready before sending a byte. But >> apparently some (many? all?) FDCs appear to be in a ready state although >> they are not yet ready to do a seek... really weird. > >It's impossible to test every FDC (at least in a free project). This >explaination doesn't make sense because the seek routine has a 55ms settleing >delay at the end (which you can increase with the SD= option), and the clean- >head routine has a 100ms delay between seeks, which makes a total of 150ms >delay. There are no other intervening commands during "clean heads" - since >seek() waits for seek complete, 150ms should be plenty of time for the >controller to be ready for another command. This also does not explain why >reading a disk would work, so I suspect there is some other factor involved >here.. > >This is the first I've heard of this problem - if you have problems with >ImageDisk, the best way to get it fixed correctly might be to work with >me on it instead of posting "fixes" to public forums. But... thats what >happens when you release source code. Ah, the step gremlin. It's an old 765(all!!!) problem. The problem is when the step pulse is set to minimum acceptable for the drive it's possible that due to internal timing of the 765 it can shorten the step timing of the first pulse by 1 count. If that occurs many drives seek badly and you get read or write errors because your not where you thought you were. Note: some old drives due to the lubricants turning to goo will also exhibit this type of error. There is one solution, step slower (SRT+1). Another problem is the 765 was designed for 77track drives (8" floppy) and there were no 80track minifloppies. So the Recal only issued 77 step pulses and would flag an see error if the drive was 80track. One fix is to issue a new Recal and see if the drive properly homed this time. The problem is there are some cores that fixed this and will issue up to 256 step pulses. The problem can also arise when using SA400/400L style drives ans some (not all) will jump track (loose the groove on the positioner disk) if stepped too far past tracks 000 or 39. Last gremlin is the 765(and cores) were designed to Seek/Recal up to 4 drives but PC hardware does not always decode this and may have drive 0 also appearing as drive 2 or 3 which makes it susceptable to being repositioned by commands not intended for it. Allison

16 years, 8 months

newbie building a scratch-built computer

by classiccmp＠memory-alpha.org.uk

Hi, > No matter what language, toggling in your code teaches (or >scares) you to write efficient code. : ) LOL, I used to seriously mess with my boss' head when dubugging code. I used to patch my code, in hex, in an EPROM emulator (a "Softy S3") as it was quicker than editing the source on my PC, assembling it and then downloading it the the emulator.... He just couldn't get his head around how I could "assemble" code in my head, even when I explained to him how easy it was when you understood how the opcodes were formed (doesn't work for all processors mind). TTFN - Pete.

16 years, 8 months

UK VCF?

by sellam＠vintagetech.com

Hello all! Just to add some clarity here: 1) No, "Vintage Computer Festival" is not trademarked internationally, nor do I have any inclination to invest the enormous amounts of money to do so. Besides, if anyone did want to try to put on a vintage computer festival and call it the "Vintage Computer Festival", there's a simple solution to that: I would hold a real Vintage Computer Festival down the street from theirs on the same dates and advertise the hell out of it and ensure that the wannabe "VCF" only got two attendees (who would be stragglers from the real VCF up the way ;) 2) There have been several discussions over the years about hosting a VCF UK. I can say it WILL happen--at some point. I just need someone in the UK eager and ready to make it happen. Talk to Evan or Pat about their experiences to see how it is done. Of course, talk to me if you're seriously interested and I'll get you started. It would be nice to finally have a VCF UK starting in 2008. 3) I am always interested in expanding the VCF to any area on Earth where there is a viable chance of it succeeding (i.e. attracting more than a few dozen attendees). I would really like to expand into Japan and South America, but I will consider any location (that doesn't conflict with existing events). This year is the 10th anniversary of the VCF (it's now on topic!) If you've never been to the main VCF in the Sillycon Valley, this is the year to come. The dates are November 3-4 (and don't be surprised if they are extended). Now that it's August, planning will begin in earnest. Speakers will start getting posted soon. Now is a great time to start thinking about an exhibit and getting it registered. A bunch of exciting announcements are in the works so stay tuned ;) -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

16 years, 8 months

UK VCF?

by evan＠snarc.net

That isn't the point, Pete. The point is: everyone knows the VCF is Sellam's thing and it would be really lame for someone else to make an event and call it a VCF. It would also just be dumb even if it weren't unethical: Sellam (and me and Hans and Pat) have done around 20 VCFs so far and we learned a LOT from the experience, so whoever is serious about making a new VCF would be wise to work with Sellam's organization, not around or against it.

16 years, 8 months

Victor Sirius/9000 Monitor

by silent700＠gmail.com

I just collected a Victor machine which I believe to be the 9000 aka Sirius 1, although it does not have a model # anywhere I can find. The fans and drive powers up, but the display does not. It appears to get its power via the 9-pin signal cable. Can anyone confirm that this is the case and if this is a common issue, perhaps with an equally common fix? -j -- Retrocomputing and collecting in the Chicago area: http://chiclassiccomp.org

16 years, 8 months

looking for DEC 875-A

by iamvirtual＠gmail.com

I am attempting to revive a Vax-11/750 that I recently acquired. During the several moves of the machine, damage was done to the 875-A power controller. The fuse holder, power control switch, and circuit breaker were all damaged. In particular, the circuit breaker (CB1) had the handles snapped clean off. The individual poles can be moved to the ON position, but always return to the OFF position. I am looking for a replacement of either the entire power controller, or, just the circuit breaker assembly. I have located a for-profit source of an 875-A, but it will be a few hundred dollars to purchase it. If anyone has a spare 875-A or breaker, I would be extremely grateful. Thanks! --barry

16 years, 8 months

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test-drb August 2007