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101090 discussions

formatting and checking floppy disks for bad sectors

by lyokoboy0＠gmail.com

I have a heap of floppy disks on hand. Most with old junk on them. Some are going bad, and have bad spots in the middle of the disk. Is there a good utility for either windows or dos that can format a floppy and mark the bad parts of the floppy to not be used? If anything, such a utility can let me find what disks are having issues and i can pitch them before i run into the aggravation of finding there is an issue with a disk down the line. --Devin

9 years, 6 months

Concurrent Computer Corporation

by stark＠mit.edu

Is there a part number on the nvram? The chips Sun used with the enbedded battery were a standard part available from Mouser. Or is there a visible battery on the board anywhere?

9 years, 6 months

KT-24 and/or -11/24 backplane info

by jnc＠mercury.lcs.mit.edu

>> I guess it will require getting ahold of a backplane, and seeing what >> I can find out with an ohm-meter. > It looks like I'll still have to do this at some point, to confirm my > theories about how the two busses are wired on the backplane > (separation of UB and EUB address lines, and cross-connection of the > data lines, for the EUB/SPC slots) I have checked an -11/24 backplane, and the wiring is indeed as I hypothesized (above). > Another mystery: The "PDP-11 UNIBUS Processor Handbook" (1985) says > (pg. 4-10) that in the 5.25" box, "only one MS11-P memory module can be > configured". Anyone know the cause/source of that restriction? > ... > I can't come up with any technical rationale for that limit? Am I > missing something? Or is it just DEC marketing, trying to limit how > powerful the machine can be? I would still be grateful for any insight from anyone about this. Noel

9 years, 6 months

ExpandaCore 18 core memory

by axelsson＠acc.umu.se

Hi again... My recent adventures with the StorageTek tape unit is on hold since I got a whole new computer to play with... (and because the disk on my linux with SCSI card had gone bad). A NORD-1 by Norsk Data AS (or Norsk Dataelektronikk AS as the company was called in those days). It is a computer built from TTL chips, a whopping 2250 of them. I seems to be in great shape and I even have drawings of the most of the CPU. More about it here : http://www.ndwiki.org/wiki/NORD-1_Serial_47 ... with pictures. :-) The NORD-1 was designed in 1967, the first one was sold in 1969 and somewhere between 60 and 120 were produced until it was succeeded by the NORD-10. A few NORD-1 ended up in Cern. The power supplies all was within 0,05V from nominal, not bad for a 44 year old computer. And except from a few broken switches, a shorted capacitor (mechanical damage) and a few missing cards it is in "running condition". Well, liberally used definition, it sort of runs. I can set the address register and inspect the different registers. When put in continuous mode the program counter runs through and loops the memory. My guess so far is that there is a problem with reading and writing to the memory. The problem is that I have no documentation over the memory module except a drawing of the circuitry used to access it. ND bought several different models of core memory for it's early computers and just adapted the interface. So once again I turn to the cctech for help, does anybody have instructions about ExpandaCore 18 from by Cambridge Memories INC, Newton, Massachusetts (also known as CMI but probably not the CMI on bitsavers). So far the only thing I've found was a newsflash in a computer magazine about a sale of memories to another computer maker. My plan is to have this machine up and running within a year, in time for the 50 year anniversary of ND founding. :-) ... and this is a long shot, if anyone has a copy of ND-NEWS (ND-NYTT in Norwegian) I would like to have a scan of it. There might be an article in it about delivering this machine to the school that I got it from. Thanks in advance, G?ran

9 years, 6 months

help identify Unisys memory board

by pontus＠Update.UU.SE

Hi A rather large Unisys memory board came up for sale locally. The seller doesn't know much about it and I'm curious which machine it comes from. Here are some picture, fairly low resolution I'm afraid: http://www.pdp8.se/slask/unisys_mem/ Do you know what it might be? Thanks, Pontus.

9 years, 6 months

DECmate, Rainbow, and Pro 350/380 parts

by shadoooo＠gmail.com

Hello Paul, hope you are fine now. I'm interested too to Pro380 boards, because I have a machine with almost no expansion. I'm trying to contact you since weeks, sent some emails but never received an acknowledgement. Maybe there are problems with spam-killers? Please check your email and let me know if you didn't receive anything. Thanks Andrea

9 years, 6 months

Nova 3 front panel

by henk.gooijen＠hotmail.com

Ahhh, thanks Ray. I still need to replace several bulbs of my NOVA3 console. Somebody knows of a source for 28V 40 mA ?grain? bulbs with wires? I could use some 10 ? and 20 as spare ? BTW, I read somewhere that the bulb to LED replacement is not as straight-forward as you may think. The small continuous current through the bulbs (to prevent thermal shock) is enough to make LEDs appear continuous on! - Henk. Van: Bruce Ray<mailto:Bruce at Wild-Hare.com> Verzonden: vrijdag 22 juli 2016 20:16 Aan: General Discussion: On-Topic and Off-Topic Posts<mailto:cctalk at classiccmp.org> Onderwerp: Re: Nova 3 front panel DG generally used 28V, 0.040 Ma (nominal), fragile wire-lead incandescent bulbs for the Nova/SuperNova/Nova2/Nova3 front panels as well as the early Eclipses. The S/130 was DG's first LED-based front panel and was much-appreciated by Field Service. More followup off-list... Bruce On 7/21/2016 10:53 PM, jim stephens wrote: > Is there anyone with documents on the Nova 3 front panel, and what > drives it? It has some number of custom DG chips, which hopefully are > good if I want to try to fire it up to play, but am interested in that > on good authority there are 28v incandescent lamps. > > A friend has an Eclipse front panel with nearly identical bezel, which > has LED's and a number of differences in the logic (different connector > to the system, for instance). So it is probably all run on 5v. > > I have not had time to figure out the driver circuit for any of the > lamps to see what that may turn up, and wanted to know whether it was > 28v lamps before I buy 40 of them. (the thing has only 2 out of a lot > of lamps). > > Thanks > Jim

9 years, 6 months

Anybody have a need for some old HP drive sleds (A3647A)?

by teoz＠neo.rr.com

Was cleaning out some stuff and ran across some HP drive sleds I don?t need. HP Model A3647A made for 4.3GB HVD 3.5? SCA 7200 RPM drives. I have 4 of them and all the screws that were inside holding the drives. Any interest? --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

9 years, 6 months

GVP Ram for Amiga Accelerators

by fast79ta＠yahoo.com

I've got an old amiga 2000, that I have stuffed a GVP G-Force 030 accelerator into. Does any one have, or know a source for the 1mb or 4mb 64pin GVP Simms? Thanks

9 years, 6 months

20MB 8" Bernoilli transfer wanted

by cclist＠sydex.com

I've been asked to refer a customer to someone with a 20MB 8" Bernoulli setup. There are only 2 disks involved and absolutely nothing is known of the provenance. I can put you in contact and you can name your terms to do the work. Note that a sector-by-sector image of the disks might be useful as it's unknown if these are PC or Apple format. Contact me off-list if interested. US only, please. Thanks, Chuck

9 years, 6 months

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