• Please review our updated Terms and Rules here

Selecting an 8" floppy drive

Just looked up the Exorciser disc manual, they are Caldata drives, model 142 (SS) or 143 (DS). Yes, they seem to be 40 way connectors, I have had one in the 'what to do with this' pile for ages, been binned so not one to look at now.

I did notice that my disc drive unit had an adapter PCB that split the drive cables to use both the Caldata drives and the normal 50 way data cables. Think mine had Shugarts in it.

About a year ago a whole pile of these Caldata drives came up for sale in one of our (UK) military clearance sales. There were something like 60 or so brand new boxed drives. I put a very small bid in and was lucky enough to not win, no idea where the ended up but be warned. These drives were spares for a rather nice 6809 based computer. The snag was that Racal decided to build the drives into the RAE transit case housing the computer such that you couldn't remove the drive and still use it, you had to use the special front panel. This made them slightly less than useless.
 
MicrocomputerSolutions said:
Qume did not make the floppy drives. I believe Y.E. Data was actually the manufacturer of the floppy drives. Drives were marketed in the U.S. with the Qume label, Y.E. Data in the Far East, and I don't remember which label was used in Europe. Y.E. Data drives did not show up for sale in the U.S. until after Qume stopped selling them, so probably a Marketing Agreement between Qume and Y.E. Data was in place.
Click to expand...

I've also seen YE Data drives with Fujitsu labels on them (3.5" ones) and I've got a couple of YED-labeled 3.5" drives with part numbers that show up on nobody's list--they were manufactured for Mitsubishi.
 
Chuck(G) said:
I've also seen YE Data drives with Fujitsu labels on them (3.5" ones) and I've got a couple of YED-labeled 3.5" drives with part numbers that show up on nobody's list--they were manufactured for Mitsubishi.
Click to expand...

At some point a Holding Company by the name of World Storage Technology sprang up at the end of the 8" floppy drive era and bought up the rights and remains/remaining parts inventories of many of the 8" floppy drive companies. I know for sure that eventually they got Siemens, Shugart, Qume, Y.E. Data, and Tandon 8" and 5.25" full height floppy drives, as well as others. After the buyouts, we started seeing drives with other names on them (example: Shugart drives with the Tandon name on them and Tandon drives with the Shugart name on them).
 
woodchips said:
Just looked up the Exorciser disc manual, they are Caldata drives, model 142 (SS) or 143 (DS). Yes, they seem to be 40 way connectors, I have had one in the 'what to do with this' pile for ages, been binned so not one to look at now.

I did notice that my disc drive unit had an adapter PCB that split the drive cables to use both the Caldata drives and the normal 50 way data cables. Think mine had Shugarts in it.

About a year ago a whole pile of these Caldata drives came up for sale in one of our (UK) military clearance sales. There were something like 60 or so brand new boxed drives. I put a very small bid in and was lucky enough to not win, no idea where the ended up but be warned. These drives were spares for a rather nice 6809 based computer. The snag was that Racal decided to build the drives into the RAE transit case housing the computer such that you couldn't remove the drive and still use it, you had to use the special front panel. This made them slightly less than useless.
Click to expand...



Besides the "CalComp Drives" there are a whole class of early 8" floppy drives they fell by the wayside early on that I would not recommend wasting your money on. A few that come to mind are: Remex, MFE, Pertec, Persci, and Miniscribe/Microscience.
 
smbaker said:
I just dragged the box upstairs. I figured it was going to be big and heavy, but I had no idea it was going to be that big and heavy...



Thanks, I will do these tests.



Speaking of which, where does someone find alignment disks? I've read of the alignment procedures in the manual for this drive (as well as other drives), and I have an oscilloscope and enough skill to use it, but I fear I'm out of luck without an alignment disk. Are these special disks, or are they ordinary floppies that just have the appropriate data stored on them?
Click to expand...



You might find an alignment disk for sale on eBay. They do show up occasionally there. You need to be careful/cautious when buying alignment disks. A single mistake or a malfunction can render an alignment disk worthless. As far as I know, there is only only company still making them (Accurite). They range in price between $150-$200 each. You can find them on the Internet. Alignment Disks are made in two flavors:

AAD (analog alignment disk) are used with a 100mhz (or better dual trace scope), and either a software program to control the drive you are aligning, OR a dedicated alignment exerciser OR a dedicated drive tester (can replace the scope and possibly the drive exerciser).

DAD (digital alignment disk) are used without a scope. Using a software program to control the drive,and read the special digital disk to measure alignment.

I use dedicated alignment drive testers (Lynx Technologies), dedicated drive exercisers (Teaco), and AAD alignment disks. I have a supply of Dysan Alignment Disks (maybe three dozen) that are about 25-30 years old. Many of them have one or more damaged alignment tracks. Remember what I said about malfunctioning drives? Over time, and with use, they wear out also.

Expensive Floppy Drive Analyzers (Wilson & Brikon) are usually available on eBay for between $500-$2000. Analyzers were built to test drives when they arrived at computer manufacturers, before being built into equipment. Most of them are not designed for drive servicing unless optional modules were ordered along with the analyzer when it came from the factory.

Drive Testers,and Drive Exercisers like the Lynx and Teaco models that I use originally sold for between $100 (Teaco Exerciser), $500 (Lynx 400 Tester), and $1500 (Lynx 460 or 470 Combined Exerciser and Tester). Occasionally, you can find these on eBay for between $20-$100.

There are/were other companies selling Drive Testers, Exercisers, and Analyzers. Some had decent reputations. I didn't have any experience with them. I've been watching an interesting looking Combination Floppy and Hard Drive Exerciser on eBay, to see if the price would come down (which it hasn't yet) made by AYA Instrumentation.

http://www.ebay.com/itm/332036689266?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

The asking price is only $50, and it's advertised for a while without any bids. I got a Lynx 470 floppy Tester for a spare, and a Lynx 500 Hard Drive Tester/Exerciser (with MFM Drive Module) in a package deal, off eBay earlier this year so I'm not hurting for a hard drive tester.

Something like this might be something you could use.
 
Last edited:
If it turns out that the Qume 8" floppy drives that you just bought have the common Qume upper head alignment problem, and you are lucky enough to get drives that don't have defective logic boards or bad stepper motors, you might be able to disable the double-sided index pulse sender or sensor and run the drive/s as single-sided drives. Double-sided drives carry double index sensors and senders. The index hole in a double-sided 8" floppy is in a different location from the index hole on a single-sided floppy disk.

When you stick a floppy disk in a 8" floppy drive, the drive determines whether the floppy is single-sided or double-sided by the index pulse that works. If you disable the double-sided index sensor or sender, the drive will not be able to detect double-sided disks, but it will still be able to detect single-sided disks, and should be able to work as a single-sided drive (if everything else on the drive still works correctly).

The nice part about running a double-sided drive as a single-sided drive is performance specs. Double-sided drives have a 3ms step rate, while single-sided drives are spec'cd at 10ms. A lot of OS software is assembled assuming double-sided drives and 3ms step rate. Even you you get the OS on single-sided floppies, you might have a problem reading and writing the disks if they were assembled with a 3ms step rate.
 
MikeS said:
I see that nobody's mentioned Tandons; despite the bad reputation of their 5.25" floppies and their hard drives I've had pretty good luck with their 1/2 height TM848s. The straight 848 is belt driven and a little fussier than the 848E which is direct drive but at the cost of a custom chip. They're both pretty solid and they also both have dual index sensors so you can read both single and double sided disks. 24V and 5V only required, documentation available.

YMMV.

m
Click to expand...

I agree.
 
MicrocomputerSolutions said:
If it turns out that the Qume 8" floppy drives that you just bought have the common Qume upper head alignment problem, and you are lucky enough to get drives that don't have defective logic boards or bad stepper motors, you might be able to disable the double-sided index pulse sender or sensor and run the drive/s as single-sided drives.
Click to expand...

Thanks. If need be, this would probably be an acceptable solution for me.

I did pull out one of the drives this week, took me a while to figure out how to get it out of the funky case, and had a look. The logic board serial number does match the drive serial number. The head carriage slides well, and the stepper feels like a stepper should feel. It's going to be another week or so before I'm able to actually try it out.

Unfortunately, I missed that $50 drive exerciser on eBay. That's the way good deals are, I always miss them by about a day. I had been considering building my own, though I wasn't planning anything quite so sophisticated (a debounced pushbutton to step and some toggles for direction, head load, etc. seems like it would be an easy way to exercise the mechanical functions of a drive).

Scott
 
I was wondering if you got it, or if someone else who happened upon this thread grabbed it up. It was available on eBay for a while, so it's probably not a coincidence that someone finally grabbed it up.

The AVA Exerciser is much more complicated (and originally much more expensive) that the Teaco Exercisers that I use. Lots of features not needed for controlling floppy drives while servicing. The plastic cased, handheld Teaco that I've has the longest (about 1985) costed about $90 back then from Specialized Tools. I got a larger metal cased benchtop Teaco around a year ago from the ACP Computer Swapmeet in Santa Ana, CA. The guy that sold it me had been trying to sell it on eBay for months starting at $50, and dropping down $25-$30 without any takers. I got it for $17. I offered the Seller $15 since i didn't really need it (other than as a backup), and he countered at $17.

The AVA Exerciser is more like the LYNX 500 Hard Drive Tester that I got earlier this year, in that you can test hard drive functions (that the Teaco cannot test). The LYNX takes interchangeable control modules so it can be used with hard drives with different interfaces (MFM, SCSI, etc...), and I got it with the MFM Module. The LYNX 500 also has a Printer Port so the results of a hard drive test can be printed out like a on Brikon or Wilson Analyzer.

I would not think that a drive exerciser would be that hard to build. Maybe a good project for a Google S-100 Group Project/Buy. Useful Features that I would recommend would be Drive Selects 1-4, Head Load, Head Side Select, Motor-on, Step-in, Step-out, Adjustable step speed, and drive connectors for both 5.25" and 8" floppy drives. LED Indicators for: Track Counter with Reset, TK00, Index, Ready, Read, Write, and Data. This is about what the Teaco Exercisers offer.

If you are not in a hurry, keep watching eBay. They do pop up occasionally. and when they are listed high initially, after a few months the price comes down. These are some of the sort of items that people find in unclaimed storage lockers and try to make a killing on, not realizing that there is very little demand for them,
 
Last edited:
MicrocomputerSolutions said:
I was wondering if you got it, or if someone else who happened upon this thread grabbed it up. It was available on eBay for a while, so it's probably not a coincidence that someone finally grabbed it up.
Click to expand...

I bought it, mainly for testing MFM and ESDI hard disks.
Would be nice to get a manual, the interface is non-obvious.

AVA_103E.jpg
 
I've had some mixed level of success with the Qume 842.

I build a 24V/5V power supply, built a 34-50 adapter, wired it all together, and loaded up CP/M. I inserted a blank unformatted disk and dir a "DIR" on it and was presenting with "Missing Address Mark". That's not surprising given that my disks are unformatted.

Unfortunately, the CP/M that I'm using (wwarthen's RomWBW) doesn't have the format operation implemented in the BIOS floppy driver. It does have a "FD.COM" tool, but I'm having some issue getting that working (won't accept serial input) and I'm not even sure if it supports my WD37C65 controller.

So now I'm sitting here looking at the WD37C65 datasheet, contemplating how to implement the format operation. :D

Scott
 
Success! I made a few changes to Wayne Warthen's FD.COM utility and was able to format the first 40 tracks of the disk. I then wrote out a test pattern to the first 40 tracks, and read that test pattern back in. Tried this cycle twice and it was successful both times. I suppose I still need to get a second drive up and running (or test a known disk) to verify that the alignment is correct?

So far, I'm only using the first 40 tracks, as I need to modify the floppy driver to support the RWC (reduced write current) signal to write to the remaining tracks. This should be doable with just a little better understanding of the WD37C65 datasheet.

This is only the first of the two drives, the 842. I haven't tried the DT/8 yet.

Scott
 
Finally looked at the drives in my Exorciser and 9845 boxes.

One has Magnetic Peripherals BR8A8-B d/s drives, the other BASF 6104 d/s drives.

Now to see if any of them work.
 
You must log in or register to reply here.
Back
Top