Replacing a Floppy drive with Solid State

[RonH]

Hello,

I have an HP16500 Logic Analyzer, it has 2 floppies (1 in the front and 1 in the rear), using these to load the OS is a very slow process, I would like to attempt to make a solid state version of a floppy drive, preverably one that will fit in the same form factor.

I have searched the net for this type of a product but I didn't see one. I wouldn't mind using an SD card if I could.

I know that these LA could be upgraded with a HD upgrade kit(E2479a) but these cannot be found anywhere.

I'm quite good at using Pic's and I would like to use this as my platform.

I'd like to get some input from people as to the feasability of this concept or any other route I should take.

Thanks

Ron

 

[on1aag]

Hi Ron,

Take a look at this:

**broken link removed**

I don't know how fast it is but it's worth checking, and you can't build
it for that price !

on1aag.

 

[RonH]

Yeah at first it looked promising, but then I noticed that you needed a driver for it to work, don't think there was ever one written for the OS of my LA!! LOL

Ron

 

[Sceadwian]

If you're good with PIC's and don't mind doing a little bit of external glue logic, just look up the floppy drive protocol specifications and replicate that on a pic. Finding the interface specs might take a little bit of searching, a quick look on google lended a lot of hits so just vary your key words a bit and see if you can find anything out there. A good start might be searching for any links of people that have designed PIC interfaces to floppy drives.

 

[Roff]

This is great. Now we have another RonH. It seems to me that user names should be filtered to prevent new guys coming on with names like, ummm, NigelGoodwin or Audio Guru.
EDIT: Looks like he's been here for a long time. He's just been an infrequent poster.

 

[Optikon]

This is great. Now we have another RonH. It seems to me that user names should be filtered to prevent new guys coming on with names like, ummm, NigelGoodwin or Audio Guru.
EDIT: Looks like he's been here for a long time. He's just been an infrequent poster.

Hmm.. yeah I was wondering.. didn't sound like your kind of post.
Maybe you need to change to R0n H to deter those common spellings.

 

[Roff]

Hmm.. yeah I was wondering.. didn't sound like your kind of post.
Maybe you need to change to R0n H to deter those common spellings.

How do you change your user name?

 

[justDIY]

you have to ask God to do it, aka our host, Electomaster

 

[jbeng]

You might be able to use something these folks offer to replace your drive in your HP analyzer. They're designed as solid-state replacements for IDE hard drives though.
Jeff

 

[on1aag]

This is great. Now we have another RonH. It seems to me that user names should be filtered to prevent new guys coming on with names like, ummm, NigelGoodwin or Audio Guru.
EDIT: Looks like he's been here for a long time. He's just been an infrequent poster.

Dear God, there are two of them !

on1aag.

 

[Sceadwian]

jbeng, the floppy interface and the ide interface are totally different.

 

[pc88]

As Sceadwian says, the floppy drive interface is very different from an IDE drive interface. A computer accesses a floppy drive at a very low level controlling the position of the head and the reading and writing of bits using precisely timed signals. You would also have to implement that timing, so I doubt you could speed up the data transfer rate. Moreover, you have no idea what sector of data the computer wants to read, so you could actually slow down the boot process if you don't emulate the right sectors at the right time. You would also have to implement track and sector headers so the computer can tell where the head is currently positioned. It would be an interesting project, but I don't think you would achieve what you set out to do.

If you want to learn more about what you're up against, here's a pretty good site:

http://geocities.com/alphacore_mail/ProbingFDC.htm

Alternatively you can check out this ebay auction:

**broken link removed**

Since you already have a working 16500C, you could buy it just for the plugins.

 

[Super_voip]

Pin 30 seems to be the only one really needed, the unfortunate thing is that it only reads at 100,000 baud -10,000 Bytes /sec. From this I would assume that even if the floppy were replaced by a SD card 10,000Byte would be the max. It all depends on the floppy interface in the HP not the floppy and like you've said it would be difficult to change the HP OS.

 

[3v0]

Are you interested in gettng the parts to add a hard drive?

I sent you a PM regarding it but did not get a reply.

Could be that my box was full

 

[Scylla313]

Replacing Floppies on the 16500

Hi RonH,

I was looking form information on the floppies in the 16500 and came accros your forum entry.
I recently got my hands on a 16500A and have the same problem: I would like to replace the floppies by something more usefull.

Have you had any luck replacing the drives?

I am now in the process of trying to get HP's LIFUTIL to format some 1.44MB floppies but I keep getting track 0 errors (I have 1 set of floppies that work but they are 720KB, and I have no spares....
Have you got the LIFUTIL working?

Best Regards,

Robert

 

[crutschow]

I am now in the process of trying to get HP's LIFUTIL to format some 1.44MB floppies but I keep getting track 0 errors (I have 1 set of floppies that work but they are 720KB, and I have no spares....

I think you can fool the drive into thinking 1.44MB floppies are 720KB by taping over the small rectangular hole on the 1.44MB floppies. That should allow you to use 1.44MB floppies (of course you need to reformat them as 720KB floppies).

 

[Nigel Goodwin]

I think you can fool the drive into thinking 1.44MB floppies are 720KB by taping over the small rectangular hole on the 1.44MB floppies. That should allow you to use 1.44MB floppies (of course you need to reformat them as 720KB floppies).

You can fool it into thinking they are 720K, but that's not enough - the magnetic characteristics of the floppies is different (1.44 need more power to the write head).

So while it may appear to write OK, it tends to give VERY poor reliabilty, and very poor long term retention.

The Commodore Amiga used 720K floppies, and I had a LOT of experience with them.

 

[Scylla313]

The LIFUTIL has the option to use high density disks as well. But I cannot get it to work: I keep getting a Track 0 error using 1.44MB disks.
Not sure whether this is a BIOS problem or just crappy ploppies.

I read about the 16500C upgrade kit.

Does anybody what was in it? And is it possible to make something that that yourself?

 

[Nigel Goodwin]

The LIFUTIL has the option to use high density disks as well. But I cannot get it to work: I keep getting a Track 0 error using 1.44MB disks.
Not sure whether this is a BIOS problem or just crappy ploppies.

Have you fitted 1.44Mb drives?, you can't use 1.44Mb disks in a 720Kb drive.

 

[Scylla313]

Hello Nigel,

After reading you reply I got slightlyu worried and rushed off to the Logic Analyser with my one and only disk that I have for the Logic Analyser. This is a 1.44MB.
This one can be read on both the rear and the front drive. Pfieuw.. (I am not completetely oblivious after all .

But I cannot read this disc with the PC's drive. I'll have a try at work (we have a stone old PC there for dust collecting.

Best Regards,

Robert