What does your 9114 sound like after a NEWM 050?

[steve]

My 9114 makes a few (4) long seeking sounds followed by 38 single track steps, followed by "MEDM ERROR" on the HP41, and then another long seek.

(Hmmm, that time it stepped 43 times)

How many times do you hear the single track stepping.

(I'd think 79, corresponding to 80 tracks)

It sounds more and more to me like either dirty heads, or (maybe) a head problem.

Just prior to writing this it _always_ failed after 38 steps, making me think there might have been some gunk stopping it get to the last (40th) track. But the evidence is that there's probably 80 tracks -- just like other disks of this size.

Does anyone know if the disk drives in these units are standard? I know that the Seagate hard drives used in the bigger brother (mains powered) units were...

[steve]

After multiple (many) uses of the head cleaning disc I have, the drive now works with about 1/3 of the 720K disks I have.

I'm still trying to buy some new 720K disks... I wonder if anybody still stocks them. Probably right next to the 5 1/4 and 8 inch disks.

[Joe]

Are you using a 720k disk in it? They won't work with a 1.44Mb disk. The drives used in the 9114 were made by Sony and they identical to the drives used in some other HP products.

Joe

[steve]

Yeah, 720K disks. I now have three of my ol 720K disks that work :-)

after MUCH cleaning.

I may try to get hold of another couple of (HPIB) drives an aquaintance has. The disk drives themselves may be compatable...

[Joe]

I have picked up a lot of 9114s surplus and never had to do much head cleaning on them. SOMEWHERE I had a list of HP-IB drives that used the same floppy as the 9114s but I have no idea where it is now. A lot of the HP-IB drives have double sided floppy drives. The 9114 is single sided. If you tell me what IB drives you're looking at I might be able to tell you if they're DS or SS. The 9121 drive is SS and the 9122 and 9123 are DS.

Joe

[Reinhard Hawel]

I didn't open my 9114 til now but I'd bet, that the Sony drives used in the 9114 and other HP products are fully compatible with the drives found today in the PCs.

Yes, I know they're only 720k, but the Shugart Bus (the cable used to connect disk drives didn't change for at least the time there are Personal Computers on the market. The presence of 3 1/2 " drives is evidently shorter than the existence of the 5 1/4 " drives and they're all compatible with each other.

You might be able to exchange the drive or you might (theoretically) even be able to connect a 5 1/4 " drive to the 9114 control logic.

There was a bunch of articles about the 9114 in PPC and CHHU publications. Maybe somebody could find technical data there and post it here. Most of the articles were about patching the 9114s ROM to change the run-down time of the drive, but there may be other details too.

[steve]

Yes, I used a 3 1/2 720K drive from one of the early HP dirves (it was one that had 720K drive and 10Mb dard disk) in a PC for some time.

I wonder if I can find new 720K 31/2 drives anywhere....?

Yeah, if anyone can locate which issues of what have information, I'll try to track them down... (I have a couple of CD's but searching them isn't too easy :-(

[Reinhard Hawel]

What I wanted to say, is thay you possibly could even use a 1.44 drive, like it's sold for abt $10 everywhere.

The bus (lug and signals) is the same and even the number of tracks (80 = 135 TPI) doesn't differ. The only difference is the number of sectors (DD=9, HD=18 in the IBM PC), which does depend on nothing but the software in the controller, that takes care of the drive (does the physical interfacing with electrical signals).

I dug out a very old Hardware book and they explain, that HD drives commonly had (have ?) jumpers, that differentiate between HD and DD.

The drive must surely "know" the difference, because in an IBM PC there is a line (line 2 on the plug, which tells you, if there's a HD or DD disk in the drive. The guys who are longer in the hardware business know, that one of the holes (the one without the switch) is for differentiating between HD and DD disks.

The drive controller applies the correct signals. In case of an 9114 the controller would always ignore the HD/DD line and format every disk to something abt >600 k (the equivalent of the PCs 720 k).

Please note, that I didn't try this out, but the theory seems to be ok. Somebody, who's in in real despair could try this out as a last resort.

A note about the using HD disks on the 9114: I wouldn't recommend using HD disks on a 9114, just because the heads of this old 720k only drive are not made for the magnetic flux needed to write to a HD disk. Newer (=HD) drives are prepared to use both media, even if the 720 k disk is long deas. I dug in my old PC disks and found lot of 720 k disks. I burnt the data on CD (which I'd recommend anyway, because a disk is a rather risky method of saving valuable data) and set aside the 720 k disks for use with the 9114. Sure, the 1.44 disks will work, but I doubt they'd have the same reliability as the 720k disks.

[steve]

May be worth a shot, even just to test if it works.

I've just got to get the right screwdriver to open the case. I have a selection of screwdriver bits, but these are so far down tiny thin holes that I'll need to get the appropriate screwdriver :-(

[Reinhard Hawel]

I guess, it's a TORX #8 or #9, but I'm not sure. I own a Torx to open my HP-71. Don't know the size now (should be #6 ?)

No, the screwdrivers from the car repair sets won't work. I always try to get high-priced quality toolsn (paid abt $5 for mine (1 piece) long ago. That might be cheaper in the U.S., because Torx is rather unknown in Europe.

I'd be really be interested, if a drive swap will work.

[steve]

I think it must be a TORX #6 because I took the drive under my arm int a store and tried the TORX #8 and it was too large.

Unfortunatly all the TORX #6 drivers were either a) sold out, b) too thick, or c) too short :-(

I now have a second (old version) 9114 and a spare drive (that may or may not work). I just need to get in to the damn thing!!!!!

The older 9114 I have has a definitely dead drive.

Actually, on a related point. I have repaired drives of this type that have become seized through solidification of lubricant. This appears to be the problem on this drive. The first symptom is that ejecting the disk becomes slower and slower. Eventually the disk won't eject and you have to pull it out. In advanced cases the heads seem to fail to retract (or something) and you end up damaging them.

I have witnessed (and fixed) this in a number of HP drives of this type and vintage that have lived in hot conditions. I believe that the more volatile components of the oil evaporate leaving a sticky greasy glue.

Fixing them requires solvent, q-tips, patience, time, and light machine oil. (did I mention lots of time and patience?)

[Reinhard Hawel]

I'm happy, that my 9114B works!!!

Yes, I've heard of the problem, but I just can't imagine where the lubricant get's hard in the drive. Is it in the 9114's mechanics or in the Sony drive itself ?

[steve]

The lubricant in the drive itself goes hard.

From memory, and it's been a while, the heads are lifted by springs, but are pushed toward the disk.

Eventually the lubricant hardens enough that the heads don't lift far enough as the user pulls out the disk (because by this time it wont eject) and one or both heads are not so gently repositioned.