Floppy emulator with flash media

There is the FlashPath adapter for SSFDC, which is a fake 3.5" diskette that goes into a regular floppy drive, and reads/writes SSFDC cards :)

I can understand no USB, but no IDE is totally useless. There are cheap (

Which is very unreliable. FlashPath is less reliable than floppy disks.

Many types of test equipment such as oscopes and analyzers, music industry equip such as synthesizers, programmable sewing machines, industrial equip, etc. When these were manufactured, the floppy was the most common removable storage. Some also have an IDE interface, but to keep costs down, many have only a single floppy drive interface used for data storage and data transfer back and forth to a PC. Unlike the PC the useful life is 10-20yrs. Replacement cost is also high.

A while back I created a gizmo that connected an IDE drive to a ST-412 controller, so it can be done, and reliably.

The question is whether it's worth it or not. The above product went into equipment where the down-time was measured in the 10's of thousands of dollars per hour, so replacement was not an option.

3.5" floppies are still available, and should be for a while. It's fairly easy to strap one up to "just about any" FDD controller.

G.

Note the smiley. I never got as far as a reliability assessment on FlashPath because I could never get it to work on any of my computers. I know the Mac guys in the office had it working but they complained bitterly that the Mac required special software, and writing to the card wasn't supported by that software.

As I understand it this is was an IDE controller, not a FDC controller. I can go out and buy an IDE to CF or SD adaptor, but I don't see any FDC to X adaptors. I have seen a few hobbyist attempts to do this but nothing commercial. The more I read the more I see there were quite a few different densities and disk formats, probably more so with the equipment I am talking about.

In that case it was well worth the trouble.

Yes, but floppies are so yesterday...and seem less reliable than I remember. What got me going on this is I have an old HP analyzer. The drive is mainly used to save configuation and data dumps. The drive still works fine (for now) but its becomming increasingly inconvenient to track down a PC with a (working) floppy drive just so I can save the data. A nice FDC to flash adaptor would be just the thing. The answer I suppose is to get a usb floppy drive and duct tape it to the side of the box.

There is nothing surprising in that. The ATA (IDE) inerface is a very simple one - a parallel port between a host and an MCU - while the FDD interface is between an FDC (floppy disk controller) like the uPD765, which is probably still cloned on modern silicon, and a piece of hardware - one or two R/W heads, a stepper to seek a track etc. Since I have done both - and I have done the FDC to the lowest thinkable detail back in the 80-s - I can see how what you need can be done, but not easily. The serial data stream on an 1.44 M floppy would be 1Mbps _IIRC_ (I would have to look at my ancient clock recovery circuits to tell that for sure), then there are a number of gaps, address fields per sector, sectors may be interleaved etc. etc. To manage the

1 MbpS NRZ data would take more than a tiny micro, and more than messing around with just a few lines of a HLL, hence no product on the market - not many people who could do it would bother, there are hotter segments and floppy disks are still available.

That's true, but not such a guge issue, once you have one format the rest will be an easy ride. The clock recovery for single and double/high density disks is different, though, only the latter are NRZ, single density write each clock pulse...

Dimiter

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The easiest way to accomplish that is by the software. All you have to do is to capture all requests to the floppy driver and redirect them to whatever image of the floppy disk. This operation is fairly trivial for the PC platform; you can even boot up from the virtual drive. Look at NE2000 bootROM procedure for the reference.

Vladimir Vassilevsky DSP and Mixed Signal Consultant

OT, but salutory perhaps: I'm moving house on Saturday, and am having to be fairly ruthless about what I take (moving from large house in the sticks to small house in prime housing market). Starting from when I went solo in the mid 80s, I built up a considerable archive of floppies - several thousand in all, with each project I worked on saved onto at least two floppies, and of course all the installation floppies from previous eras (Windows 3.1, 95 etc etc). Since then hard disk capacities have ballooned, and at some point I copied all the project data onto my server here and onto CDs...

... Which is just as well, since none of the floppies appear to now be readable. Tried a random handful with a new drive; no go - "disk not formatted". Thus, *all* my floppies are being binned. I also had several hundred 5.25" disks, including some new ones still in unopened boxes... and a drive. All heading for the bin. Same goes for the short-lived and troublesome Colorado Jumbo tape drives and a dozen or so backup tapes. Seems a shame, but hey. Same goes for a filing cabinet full of data sheets and a large pile of databooks, all now obsolete due to the interweb...

The company I work for now has *one* filing cabinet in the building (for invoices). I had about four cabinets' worth of paper. I conclude that I'm a dinosaur and have been doing this job too long.

Steve (who is just about to try reading some of his CDR archive, and is expecting them to be mostly junk too...) (PS: if anyone has a use for several thousand used floppies, in 3.5" and

5.25" formats, and a 5.25" drive, and can collect from Selsey in Sussex, contact me ASAP. I shall not be holding my breath.)

Not really. This gizmo emulated an MFM hard disk drive. The IDE drive was just to record the data.

The data format of a floppy is not that different from the data format of an ST-412 drive. MFM is MFM.

G.,

On Sep 5, 11:08 am, "Steve at fivetrees"

On the other hand, I am resurrecting a bunch of TRS-80 Model II systems (and some other even older stuff), and almost all of the 8" floppies I have for this system are reading just fine, including backup disks dated as far back as 1977 (those disks weren't written on the Model II, they were written on an IBM data entry machine, basically a keyboard and 8" floppy drive built into a large desk).

The big danger to these media is from not being stored in temperature/ humidity-controlled environments: the biscuit develops some kind of fungal growth that displaces the magnetic coating.

Had a related experience recently. Before I retired an old system with floppies I used it to copy all floppies with data I needed via RS-232 to a DPS system as FD image files, where the old system is emulated anyway.

It turned out that I could read floppies as old as 1988; no lost data at all. I think some of the DD floppies I had been rude enough to write as HD ones had forgotten this or that, though, but I seem to have had enough copies of all so I got my data.

However, when I tried - don't remember why now - to write to floppies which were 10 years old or so, it did not work! The floppies had been readable before trying, the drives were in perfect order, checked with newer disks, just the old floppies were non-writable, non-formattable (well some tracks did format but overall they were no good).

Dimiter

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These embedded devices are not PCs, there is no source code to be had. Considering the vintage, its probably all custom firmware burned into just-large-enough proms with no OS, no BIOS. After reverse engineering the code and HW design you would likely find there was no way to do what you suggest without a HW redesign.

I thought one difference between the FDC and IDE interface (right at the connector), was that the FDC does talk at that lowest level so that MFM, FM, GCR whatever is present right on the ribbon cable, but for IDE this lower layer is done by chips on the drive itself. At least that is what I thought a modern IDE drive did. I now see that the ST-412 was one of the very first. Was it considered IDE back then?

Hah! The TRS-80s I remember were the cheapskate versions with the cassette (Kansas?) interface.

During my clearout, I also found a few 8" floppies. 160k, IIRC, which seemed massive at the time. These were from a Motorola 6800 development system, back when CPU development platforms were bespoke and cost several arms and legs... so I felt fairly comfortable about junking those ;).

(If you'd like the disks, email me and I'll retrieve them and send them to you. I don't suppose they're available in the shops these days ;).)

Ah. Didn't know that. These have most definitely *not* been stored thus. Ah well. Needed an excuse to dump 'em anyway.

Talking of antique computers, does anybody have a home for: a) Jupiter Ace (Forth machine based on Z80) b) Sharp PC-1350 (handheld with BASIC and full QWERTY keyboard) with

16k (whoa!) RAM cards c) Dragon 32 (6809 home 'puter), non-functional but (I'm told) easily fixed d) Psion Series 3 with spreadsheet card etc

Let me know. Seems a shame to bin 'em.

Actually, anyone have any use for reel-to-reel audio tape decks (TEAC) (4-track 3340 with 4-track DBX, and 2-track ???? 1/4")? I won't bin these. Sex on legs.

Or how about an HP 7550 A3 pen plotter with shedloads of spare pens? Built like a tank. Takes about the same space. Noisy. But also sexy ;).

Shit, I really *am* a dinosaur.

Steve

I'd kill for these three items, especially the Jupiter Ace; who do you need rubbed out?

Don't bin them. I have a KIM-1, a PC-jr, a Radio Shack CoCo, a DEC PDP 8/l and 11/70,

3 LSI 11's, a VAX CPU board, a Northstar Horizon, a Sharp PC-1350 and a Curta mechanical calculator.

Believe it or not, I gave away an Apple Lisa about 10 years ago...

I've a 3340 up in the garage rafters along with a TEAC 6-in, 4-out mixing board. The board has come in handy a couple times a year for various projects. The 3340, not. They are still getting a pretty good price on ebay...

Only if you take my Houston Instruments C-size plotter. Comes with my own special custom adapter so you can use a Pilot rolling pen in place of the accursed technical pens.

Many of us are. Which reminds me, how about the Roland Poly88 Synth and the Hallicrafters Skybuddy that's next to the TEAC? Want them?

You don't even want to get me started on my '80s pro video equipment collection.

You perhaps forget that with an emulation, you wouldn't _need_ clock recovery etc - the data would be a 'nice' synchronous data stream.

Regards,

--
Mark McDougall, Engineer
Virtual Logic Pty Ltd, 
21-25 King St, Rockdale, 2216
Ph: +612-9599-3255 Fax: +612-9599-3266

I've a couple of C64s, a chicklet keyboardy ZX-81 I built, and I gave away the Altair 8800 I'd built. Boxes of stuff laying about might surprise my further recollection, if I went through them again.

I remember using mechanical calculators with the hand-crank and the top that moves over and over and over during a multiplication. Never owned one, myself. If you ever get a mind to look for a home for that

11/70, though.... look me up. I enjoyed those and would get some use out of it, teaching others.

Okay. I admit it. I had a lot of fun on the PDP-8/e I'd used earlier and the RK05s and DECtape drives. Reminds me, just found a cache of DECtapes. I wonder what remains on those? And some old paper tapes

-- mylar, some of them. One of these days....

Cripes. I remember those. Never owned one but _before_ it first came out and was announced to the public, the Apple office here in the area had them and called me in to look. I believe I was told the price would start around $10k or more and that was _way_ outside of my ability. (Born poor, you know, and had other priorities for what little I had left of my hard earned cash.)

Somewhere around here I may still have my Persei drives. Voice coil floopy drives, instead of steppers. Can't say they were as reliable as the significantly slower Shugarts, though.

Egads. Now if that were an E size....

hehe.

Jon