test-drb January 2005

test-drb@ccmp.vtda.org

254 participants
551 discussions

Troubleshooting an IBM 5155 - (portable personal computer)

by CCTalk＠catcorner.org

> > > The heads are selected by U4 (75451 dual AND gate/driver), > > the outputs of > > which are pulled to+5V, and slo drive the bases of Q7 (Head > 1) and Q6 > > (Head 0), PN2222 transistors via restors. One input of each > > of the AND > > gates comes from the power-OK circuit, built round Q9 and Q10 > > (as this is > > common to both heads, it's working correctly), the other > > input comes from > > the sides select signal on the connector (U4b, for head 1) or > > from that > > signal inverted by U8b (7414) on U4a, for head 0. That should > > give you > > some components to check. > > > Are you sure U4a drives Q6 and U4b drives Q7? Tracing the > board shows them > on Q7 and Q8. Yikes. Any chance you could scan the schematic > and email it? > 1bpp tiff, bmp or pcx would do. The higher the resoultion the > better, but I > could probably make due at 150dpi. > > You could even send it in seperate parts. I could then stitch > them together. > Making some preliminary measurements, it's beginning to look > like a head > problem. I am reluctant to actually load the heads until I > have to. I still > have not "cleaned" the top head thouroughly, although it seems clean > examining it through a loop. > > I may just install a pair of known good drives in the machine and > troubleshoot these two independantly. At least I would have > matching drives > in the machine until I can figure out what is wrong here. > > Thanks, > Kelly > I don't kwow what it means when I reply to my own replies, but here goes. I have the same continuity measurements on head 0 and head 1. However, if I swap the controller board (I know, Tony, you generally frown upon "swapping" for troubleshooting, but I couldn't find anything electrically), the problem stays with the drive. So, if I have the same continuity, and the problem doesn't seem to be on the controller, I can only guess either dirty or magentized heads. I noticed that if I close the drive with no media and open it slowly, the heads stick together until there is a bit of load on them to pull apart. Kind of like the are lightly magnetized. Since I don't have access to a tape head demagnitizer (hey, all I use is DTRS for my recording), how else could I demagnetize these heads? I'm going to bed now. More tomorrow. Kelly

19 years, 7 months

Troubleshooting an IBM 5155 - (portable personal computer)

by CCTalk＠catcorner.org

> > > The heads are selected by U4 (75451 dual AND gate/driver), > the outputs of > which are pulled to+5V, and slo drive the bases of Q7 (Head 1) and Q6 > (Head 0), PN2222 transistors via restors. One input of each > of the AND > gates comes from the power-OK circuit, built round Q9 and Q10 > (as this is > common to both heads, it's working correctly), the other > input comes from > the sides select signal on the connector (U4b, for head 1) or > from that > signal inverted by U8b (7414) on U4a, for head 0. That should > give you > some components to check. > Are you sure U4a drives Q6 and U4b drives Q7? Tracing the board shows them on Q7 and Q8. Yikes. Any chance you could scan the schematic and email it? 1bpp tiff, bmp or pcx would do. The higher the resoultion the better, but I could probably make due at 150dpi. You could even send it in seperate parts. I could then stitch them together. Making some preliminary measurements, it's beginning to look like a head problem. I am reluctant to actually load the heads until I have to. I still have not "cleaned" the top head thouroughly, although it seems clean examining it through a loop. I may just install a pair of known good drives in the machine and troubleshoot these two independantly. At least I would have matching drives in the machine until I can figure out what is wrong here. Thanks, Kelly

19 years, 7 months

Windows Backup program?

by rigdonj＠cfl.rr.com

This past weekeend I found a ADIC 1200D DAT tape library in a scrap pile. It has a Sony DAT-2 tape drive with an autochanger and holds up to 12 tapes. I'm thinking of using it on my PC. Can anyone recommend a good (and cheap!) backup program that will work with Windows 98? Joe

19 years, 7 months

DOS feature on formatting disk

by dwight.elvey＠amd.com

>From: "Dan Williams" <williams.dan(a)gmail.com> > >On Tue, 18 Jan 2005 10:16:11 -0800 (PST), Dwight K. Elvey ><dwight.elvey(a)amd.com> wrote: >> Hi Randy >> I've written special drivers for the floppies >> under DOS in the past so that isn't a real >> issue. I just wish it would work without me >> having to pull out the reference books to >> deal with it. >> It works incorrectly in both MSDOS and PCDOS. >> It is just annoying. The /u should mean just that, >> unconditionally format. >> Dwight >> > In MSDOS the /u doesn't actually mean unconditional in the normal >sense. It means do not save unformat information, it will still stop >if it gets errors. > >Dan > Hi Sure but what about not reading track 0 before formatting means it should abort the formatting without first doing a low level format of that track. It is just stupid. If I completely erase the track, it formats just fine. As Sellam says, it is just stupid design. Dwight

19 years, 7 months

AMI Not

by Innfogra＠aol.com

This is not an AMI chip. It is from a small foundry in Canada that was the first second source for intel memory chips. I was informed of the name a couple years ago when I sold some of these on epay. But did not save it. Perhaps someone on the list knows. My 1101s were from 1973. I think the foundry only existed for about three years in the early 70s. Paxton Astoria, Oregon PS, If you want to part with any I am interested.

19 years, 7 months

DOS feature on formatting disk

by cb＠mythtech.net

>I know. It's another one of those stupid things that MS did with DOS that >makes absolutely no sense. Just format the damn disk and report any >errors for the USER to decide. > >I once came across some program on the WWW that supposedly rehabilitates >such disks (most likely by doing an LLF on track 0) but unfortunately I >never bookmarked it. I used to run into this all the time. When you format a floppy for the Mac, DOS will then report the Track 0 error and refuse to reformat it. I always just formatted the disk for DOS on my Mac to get around the problem (and then got really irked when I was told "The mac is not compatible with anything else"... REALLY, not only can I read/write PC disks, but I could read/write all the PC users files long before any of them had tools to deal with Mac files!) -chris <http://www.mythtech.net>

19 years, 7 months

DOS feature on formatting disk

by dwight.elvey＠amd.com

>From: "Dave Dunfield" <dave04a(a)dunfield.com> > >>I once came across some program on the WWW that supposedly rehabilitates >>such disks (most likely by doing an LLF on track 0) but unfortunately I >>never bookmarked it. > >When I was selling my software on diskette, I wrote my own tools for diskette >duplication, using a Victory autoloader - I also boiled-down the core functions >into a one-at-a-time disk command line duplicator that works with standard >floppy drives called XDISK. > >Like most disk-to-file copiers it will read a complete image of the floppy >track by track into a disk file - unlike most file-to-disk copiers, it >will low-level format, write, and verify each track in a single pass as it >writes the file back to a disk. It does not care *WHAT* is previously on the >disk, as the first command it issues on each track is "format track". > >This can be used to restore disks that DOS refuses to format due to problems >in track-0 (just write out a blank floppy image) - I can send it to you if >you like (runs under any version of DOS). > >Regards, >Dave >-- >dave04a (at) Dave Dunfield >dunfield (dot) Firmware development services & tools: www.dunfield.com >com Collector of vintage computing equipment: > http://www.parse.com/~ddunfield/museum/index.html > > > My only issue there is that I'm never sure how big to make the various gaps. Anyway, the strong magnet works, it is just a hassle. Dwight

19 years, 7 months

DOS feature on formatting disk

by dwight.elvey＠amd.com

Hi Randy I've written special drivers for the floppies under DOS in the past so that isn't a real issue. I just wish it would work without me having to pull out the reference books to deal with it. It works incorrectly in both MSDOS and PCDOS. It is just annoying. The /u should mean just that, unconditionally format. Dwight >From: "Randy McLaughlin" <randy(a)s100-manuals.com> > >From: "Dwight K. Elvey" <dwight.elvey(a)amd.com> >> Hi >> DOS has an irritating feature when asked to format >> a disk. If track 0 is partially readable it will >> fail to format, even if you use the /u option. >> I've been moving data from one machine to another >> and the source machine has a flaky drive. It sometimes >> trashes track 0. >> I've found that the only way to get around this problem >> is to wipe the disk with a strong magnet. >> Why can't it just try to format first and then check >> track 0. Why must it fail to format because track 0 >> is partially readable when I specifically asked it >> to unconditionally format? >> Dwight > >Try picking up the format program from freedos/opendos and see if it does >the same. If needed it may be able to be modified. > > >Randy > > >

19 years, 7 months

DOS feature on formatting disk

by dave04a＠dunfield.com

>I once came across some program on the WWW that supposedly rehabilitates >such disks (most likely by doing an LLF on track 0) but unfortunately I >never bookmarked it. When I was selling my software on diskette, I wrote my own tools for diskette duplication, using a Victory autoloader - I also boiled-down the core functions into a one-at-a-time disk command line duplicator that works with standard floppy drives called XDISK. Like most disk-to-file copiers it will read a complete image of the floppy track by track into a disk file - unlike most file-to-disk copiers, it will low-level format, write, and verify each track in a single pass as it writes the file back to a disk. It does not care *WHAT* is previously on the disk, as the first command it issues on each track is "format track". This can be used to restore disks that DOS refuses to format due to problems in track-0 (just write out a blank floppy image) - I can send it to you if you like (runs under any version of DOS). Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html

19 years, 7 months

Data recovery on Toshiba T3100 laptop

by r_a_feldman＠hotmail.com

A good MS-DOS program to use to transfer files off an old computer is Xport (search on Google for XPORT21). It includes a procedure to send itself over a serial line to the target computer, so you don't need to have a working floppy. It also includes instructions on wiring the cable. Bob Date: Sat, 15 Jan 2005 12:09:37 -0600 From: Jim Leonard <trixter(a)oldskool.org> Subject: Re: Data recovery on Toshiba T3100 laptop To: General Discussion: On-Topic and Off-Topic Posts <cctalk(a)classiccmp.org> Message-ID: <41E95C61.5000901(a)oldskool.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Tore S Bekkedal wrote: >I have a VGA monitor, no CGAs around, but I also have a 9-pin to 15-pin >male-male cable - but aren't the voltages different? Voltages aside, the technologies are completely different; it won't work. I would follow the "boot-a-floppy-and-transfer-via-kermit" method. Or use a DOS-based program like FastLynx or even the built-in transfer in DOS 6.x's intersvr/interlnk programs. -- Jim Leonard (trixter(a)oldskool.org) http://www.oldskool.org/ Want to help an ambitious games project? http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/

19 years, 7 months

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test-drb January 2005