Floppy Woes on SE FDHD

[jwse30]

I have been slowly getting back into my vintage Macs. When I tried to fire up my SE, the Hard drive was dead, as was the floppy drive. So I replaced both, though I don't know if the floppy drive was any good. I managed to get a System onto the "new" hard drive via a SyQuest drive, but the floppy still didn't work.

So I sent the motherboard out to have some work done to it, after being told the borne (sp?) filter may be bad, with no effect. I bought an 800k external drive which works fine with this machine. I recently traded for a third internal floppy drive, figuring that the first two were bad (the second one made some pretty rough noises when first installed; I sprayed it down and cleaned it up with some contact cleaner...). When I installed this third one, it didn't work either. I then swapped out the motherboard with an SE/30 motherboard I had laying around, and it didn't work with it either. (I honestly don't recall if I tried the 800k drive with the SE/30 though)

One thing I did notice with the SE board (and maybe the SE/30?) was that if I put in an 800k disk the dialog box would give the option of formatting single sided, and if it were a HD disk, it wouldn't. So I think I've got the right ROMs. I don't remember ever swapping them or the board out of this machine, but last time I used it was likely ten years ago.

So assuming I have a good floppy drive (I trust it was good when it left the person I got it from), is there anything else I could be looking for? I've never heard of a ribbon cable going bad, but I guess it could be possible. Do the HD drives take more juice than an 800k drive and my power supply isn't giving it what it needs?

That's all I can think of at the moment. If anyone has any other ideas, I would really like to hear them.

J White

 

[uniserver]

i just realized from my own floppy Woes, with the 128k i am working on.

i am having the exact same issues as you are having right now.

Just realized there are ( 2 ) filters that control the internal and external floppy drive.

i have only been replacing the one.

i'm going to replace the other one in my 128k tonight i will let you know.

boots fine from external.

internal either : ejects / partially boots / makes funny noises for a bit then ejects / on a rare occurrence it will boot depending the amount of tries.

 

[jwse30]

boots fine from external.internal either : ejects / partially boots / makes funny noises for a bit then ejects / on a rare occurrence it will boot depending the amount of tries.

Haven't tried more than once or twice per disk, so I never got to the rare occurrence of it booting, but other than that, your description sounds like my experience.

J White

 

[Paralel]

But does the internal somehow route through the 2nd filter, while the external doesn't? That seems weird.

 

[uniserver]

Hey man.

In my situation the issue was wire 9 and wire 20 needed to be cut counting from the red stripe on the floppy cable.

In order to use the 800k drive with my 128k board.

- Inspect your floppy cable and maybe try one from another machine.

- Sometimes a bad floppy drive will screw up the disk you have been using… making you think everything is screwed...

When it was just a bad floppy drive that keeps screwing up your boot disks, making them not work even in a

good working floppy drive.

But does the internal somehow route through the 2nd filter, while the external doesn't? That seems weird.

Both the internal and the external floppy ports route through both resistor networks.

Also the mouse shares some of the network on the filter right of the internal floppy port.

One of the serial ports share some of the network too, on the filter right in front of the internal floppy connector.

 

[jwse30]

Well, after messing around with three HD floppy drives and two ribbon cables, I've got one combination that seems to be working somewhat. I have a few disks that the drive won't mount, but it will mount almost 800k disk I put in it. It will initialize HD disks and mount ones that it has formatted. The few I have been using while trying all this out won't mount though. I am going to try to rewrite them in my SE/30 and see if they work then. I am also going to try to read the disks I formatted with this drive in the SE/30 and make sure they can be read on another machine.

One thing that seemed to help is using the bottom floppy connector on the logic board (when the screen is facing down, like when you're working on it) instead of the top one. I didn't think that mattered, perhaps I've got a bit of corrosion on the top one?

Hopefully I'm close to getting this one working again,

J White

 

[techknight]

Well if you can format/read HD floppies on the machine your using, but they cant be read on another one, your heads are out of alignment. the track alignment is alot tighter on HD than DD. So DD can work fine (mostly) but HD be dead.

Only way I know of realigning the heads is let the motor sit and run on track 0 of an HD disk. (a readable one in all machines). Then measure the head output with a scope. Unlock and twist the stepper motor until your amplitude is at its maximum. Then tighten the stepper motor locking screw.

Voiala.

 

[jwse30]

I tried out the disks I was formatting with the SE with my SE/30 and the SE/30 can read them. The disks that the SE wouldn't mount can't be mounted by the SE/30 anymore either (they did just prior to me doing all this). I made a new System 6 startup disk with the SE/30, and the SE booted off of it successfully.

The disks that won't work in either machine now don't seem to be able to be reformatted either. They must have gotten really chewed up through all this.

I think I've got a combination that works now.

J White

 

[Paralel]

Watch out, that drive might be a disk eater. I've seen that happen before with a few systems of that era. You stick a disk into it a few times, and the disk is trash regardless of what system it is put into.

 

[uniserver]

yes, if you suspect a drive that is eating disks pull it apart and have a look at the heads.

 

[techknight]

well if they get highly magnetized it can ruin disks. Just like the old cassette decks did back in the day.

the simplest demagnetizer is if you have one of the old trigger-style soldering guns. they have a big transformer in them and make great degaussers.