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5 1/4" Floppy Disk giving bad sectors on format

T-Squared

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Well, my adventures with my Compaq Portable III continue. I received a junk CP today and I was able to use the plasma screen to replace the working CP without the screen. The thing is, the 5 1/4" disk drive on my working CP is not working quite correctly. Whenever I format a floppy disk, I get over 2/3 of the disk in bad sectors. I'm not scared, cause I think the previous owner of the computer never cleaned the read-write head with a cleaning disk, and I think the head is clogged with years and years of dust and really-tiny disk flakes. Is this the reason, or is it something worse?

I'd like to be able to copy Arachne to my computer so I can surf the internet early-1990s style! (OR maybe go a little further back and dial-in to a still-running BBS!)
 
Entirely possible--also the carriage rails can be quite dirty, interfering with the positioning. One of the problems with most PCs is that the power supply fan sucks in crud through the disk slot, depositing it all over the heads.

Use some isopropanol (isopropyl alcohol) and a soft lint-free swab to clean the heads, being careful not to push the heads laterally (in a tangential direction).
 
Yep, as Chuck says. Heads, rails and then maybe speed adjustment in that order. I've found checking/dealing with those factors have solved 90% of any disk issues I've had. Dont forget to use good disks too. If they are starting to deteriorate they will just leave crud all over the heads again.

Tez
 
Another thing to consider and to address is that often times a lubricant similar to white lithium grease was used to lubricate the mechanism that moves the heads (in newer 3-1/2 floppy drives this is usually a spiral cut rod attached to a stepper motor, in older 5-1/4 drives this may be a geared track or some sort of a similar spiral cut rod setup) this grease may have dried up and is essentially blocking movement of the mechanism, it's also possible that this grease may have attracted dust and other contaminants that may also need to be excised in order to restore proper head positioning capability. Again use a lint free cleaning material dampened with some Isopropyl Alcohol to clean any debris and old possibly deteriorated lubricant, then remember to apply fresh lubricant, myself I have an aerosol can of 'Primis' brand 'Light Viscosity Lube Gel' (originally purchased in the Automotive department at Walmart) that I find is thick enough to stick to components without dripping all over everything and is slick enough to likely provide sufficient lubrication for most moving components in a computer system without being thick enough to impede movement.
 
Another thought--make sure that you're using DSDD floppies and not DSHD. All 5.25" floppies are not the same--and the drive has no way to tell them apart. 360K/DSDD floppies generally have a reinforcing ring around the inner hub hole, while 1.2M/DSHD does not.
 
Another thought--make sure that you're using DSDD floppies and not DSHD. All 5.25" floppies are not the same--and the drive has no way to tell them apart. 360K/DSDD floppies generally have a reinforcing ring around the inner hub hole, while 1.2M/DSHD does not.
I would say the other way around.
Compaq Portable III should have 1.2 MB drives, and trying to format a DSDD diskette into 1.2 MB typically results in about 800 KB in bad sectors.
Use DSHD.
 
Either way--if you're formatting 1.2M, use DSHD; if you're formatting 360K, use DSDD. A 1.2M drive can format either (with the usual proviso of trying to read the result in a 48 tpi 360K drive). Don't mix formats and media.

Unfortunately, most new users don't understand or appreciate the difference.
 
i would say the other way around.
Compaq portable iii should have 1.2 mb drives, and trying to format a dsdd diskette into 1.2 mb typically results in about 800 kb in bad sectors.
Use dshd.

that's exactly the problem i've been having! 8d
 
HUZZAH! IT WORKED! 8D

And I didn't break my computer in the process. |3 (All that was lost was a small piece of a holding clip for some system RAM SIMMs, cause I wanted to see if some memory from my Junq Compaq would be useful in expanding my working Compaq.)

I'm probably going to have to get a pack of DSHD disks, cause all I have are the DSDD & SSLD(?) disks for my Apple II and C64.
 
...I'm probably going to have to get a pack of DSHD disks, cause all I have are the DSDD & SSLD(?) disks for my Apple II and C64.
By all means get some HD disks, but as Chuck pointed out there's no reason why you can't use pretty well any kind of soft-sector diskette as long as you format it appropriately!

FORMAT A: /4 or FORMAT A: /F:360 will format and prepare a 360K DSDD disk; there are also options for single-sided disks and various other sizes, but you probably won't need those.

You might want to review the FORMAT options:
http://en.wikipedia.org/wiki/List_of_MS-DOS_commands
 
A lot of what's being asked lately about the 80's era systems has been answered over and over again here. I'm not blaming anyone, but perhaps we should have a FAQ that covers floppies, hard disks, displays, operating systems, etc. for the 8088-80386 PC-compatibles. I understand that most people get the systems "naked" and don't have a manual and have never had to low-level format a hard disk and probably don't realize that a 30MB hard disk at one time was a large device (i.e. if you want to hook up that 20GB drive, small as it may seem, you're going to have to jump through some hoops)).

Do we have anything like that at present?
 
Yeah, you want to stay away from the disks for Apple computers and probably the Commodore ones too, there is actually a difference in the drives (and the disks too) for the comparable Apple versions. If I remember correctly the difference is partly in the number of tracks the media contains for Apple drives. This difference in number of tracks is probably the source of your problems.
 
Yeah, you want to stay away from the disks for Apple computers and probably the Commodore ones too, there is actually a difference in the drives (and the disks too) for the comparable Apple versions. If I remember correctly the difference is partly in the number of tracks the media contains for Apple drives. This difference in number of tracks is probably the source of your problems.
The drives are indeed different, and the format (including the number of tracks) is also different from a PC, but the diskettes themselves are no different; as mentioned above, you select the number of tracks etc. when you format a diskette. These days there are really only two types of 5.25" floppy diskettes, DSHD for PC-compatible 1.2MB HD drives, and DSDD for pretty well everything else, and the 1.2M HD drives can use either type; the only type of disk that PC-compatible systems can't handle are the relatively rare hard-sector diskettes which have more than one index hole.

Of course this doesn't mean that you can actually read and make sense of what an incompatible system has written on a disk, but you can certainly use the disk if you format it appropriately.
 
Yes, perhaps a wiki thing called "The Care and Feeding of Computers That Came Out Before You Were Even Alive"
It would help some people. I prefer only using OEM replacements in systems. Generally works right away. :) Especially when using IBM equipment.
 
A lot of what's being asked lately about the 80's era systems has been answered over and over again here. I'm not blaming anyone, but perhaps we should have a FAQ that covers floppies, hard disks, displays, operating systems, etc. for the 8088-80386 PC-compatibles.

Yeah, I wouldn't have thought it necessary, but it seems we do. A sticky thread should do. Maybe I'll take a hand at writing something later today.

It's funny - I've known this stuff so long that I can't imagine someone else wouldn't know. But, if you've never been told, or don't know how the hardware works, it wouldn't be something you would think about.

Reminds me of one time when I was talking to a guy bringing 1940's era Plymouth out of his storage unit. The whole car had been repainted, and it looked great, and he was talking about how long it had taken to repair and fix it up, and how he'd had the seats redone, etc. I mentioned something like "Where do you get leaded gas? Is there a lead substitute you can use?", and he said "Leaded gas?"...

Yes, he had honestly forgotten about the requirement of leaded fuel.

So, yes, a quick "this is what you need to know about IBM PC's" would be handy.

-Ian
 
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