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MSD SuperDisk drive modifications to support GCR?


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Woot!

post-27864-0-46152000-1432696622_thumb.jpg

 

I found my MSD SD-2s, got them cleaned up and working.

 

I did a little research while I was cleaning them up. Given the schematics, like the 1541 there is no floppy controller chip. All work is done by the 6511Q and its I/O ports, similar to the 1541 and its 6522s. No hope in making the drive double-sided without a good bit of work: it looks like the 6511Q has a free I/O pin or two, so with some wiring and DOS modifications it may be possible to set up a head-select.

 

That aside, one of the things I came across was that MSD made modifications to the TEC (TEAC?) FD-501 to accommodate GCR. None of this is mentioned in the schematics I have.

 

If true, does anyone have information on what had to be modified on the drive?

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OLD CS1 wrote:

 

> I found my MSD SD-2s, got them cleaned up and working.

 

I had to have Ray Carlsen fix my MSD's. See

 

http://blog.retro-link.com/2012/08/front-back-corroded-caps-and-others.html

 

> ...one of the things I came across was that MSD made modifications to the TEC (TEAC?) FD-501 to accommodate GCR.

 

It was TEC.

 

> If true, does anyone have information on what had to be modified on the drive?

 

I can't help you on that one.

 

FCUG celebrating 33 years,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 -

http://www.portcommodore.com/commvex

 

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Woot!

attachicon.gifmsd sd-2.jpg

 

I found my MSD SD-2s, got them cleaned up and working.

 

I did a little research while I was cleaning them up. Given the schematics, like the 1541 there is no floppy controller chip. All work is done by the 6511Q and its I/O ports, similar to the 1541 and its 6522s. No hope in making the drive double-sided without a good bit of work: it looks like the 6511Q has a free I/O pin or two, so with some wiring and DOS modifications it may be possible to set up a head-select.

 

That aside, one of the things I came across was that MSD made modifications to the TEC (TEAC?) FD-501 to accommodate GCR. None of this is mentioned in the schematics I have.

 

If true, does anyone have information on what had to be modified on the drive?

 

 

Those looks great! I bet they weigh quite a bit for shipping :)

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OLD CS1 wrote:

 

> I found my MSD SD-2s, got them cleaned up and working.

 

I had to have Ray Carlsen fix my MSD's. See

 

http://blog.retro-link.com/2012/08/front-back-corroded-caps-and-others.html

 

> ...one of the things I came across was that MSD made modifications to the TEC (TEAC?) FD-501 to accommodate GCR.

 

It was TEC.

 

> If true, does anyone have information on what had to be modified on the drive?

 

I can't help you on that one.

 

FCUG celebrating 33 years,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 -

http://www.portcommodore.com/commvex

 

 

 

Wow RobertB, you have quite the collection of MSD drives as well! I envy the storage space some of you seem to have for this type of thing ;)

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Those looks great! I bet they weigh quite a bit for shipping :)

 

Yeah... that is why I just cannot sell them. The shipping would be too much for anyone to bother!

 

 

Wow RobertB, you have quite the collection of MSD drives as well! I envy the storage space some of you seem to have for this type of thing ;)

 

I like that one of them has a handle.

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  • 2 weeks later...

 

Wow RobertB, you have quite the collection of MSD drives as well! I envy the storage space some of you seem to have for this type of thing ;)

 

For me that is exactly the problem: I do not have the storage space for this stuff. I used to have a three bedroom house which held my hobbies just fine. After I finally got rid of that albatross I moved into a much smaller two bedroom apartment and most of the house went into storage. Now I am trimming down my excess (very easy to accumulate if you are not careful,) and squeezing what I can into my small office.

 

On another topic, though, I have found over the years that people can be quite rude and annoying about the purging process. I have often offered stuff for nothing more than shipping cost. To illustrate the urgency of moving equipment out of my possession I would note that if I cannot GIVE this stuff away then it has to go to the dump. Oh, man, the nasty messages and hate mail I get for that. But the reality is I cannot spend my time and money warehousing stuff that is no good to me just because it MIGHT be useful for someone else in the future. Of course, if I were to factor in storage and moving costs for all of the equipment in sale pricing I would be decried for gouging, and not one of the people giving me hassle were offering to take the stuff.

 

I refuse to be one of these sad fekkers at the flea market with a table (or storage unit) full of stuff I have held onto over the years for no other reason than because SOMEONE might need it one day. Mind you, I have found an interesting thing or two at such a place, but I do not want to be that person. Even worse would be leave a collection of "junk" for my family to dispose of after I meet an untimely demise. I am trimming what I have down to reasonable and useful size, cataloged, and more easily handled.

 

Okay... I am done now :)

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  • 1 month later...

 

Woot!

attachicon.gifmsd sd-2.jpg

 

I found my MSD SD-2s, got them cleaned up and working.

 

I did a little research while I was cleaning them up. Given the schematics, like the 1541 there is no floppy controller chip. All work is done by the 6511Q and its I/O ports, similar to the 1541 and its 6522s. No hope in making the drive double-sided without a good bit of work: it looks like the 6511Q has a free I/O pin or two, so with some wiring and DOS modifications it may be possible to set up a head-select.

 

That aside, one of the things I came across was that MSD made modifications to the TEC (TEAC?) FD-501 to accommodate GCR. None of this is mentioned in the schematics I have.

 

If true, does anyone have information on what had to be modified on the drive?

 

 

Floppy disk drive mechanisms are not inherently FM, MFM or GCR. The formatting/writing/reading of the disk is up to the floppy disk controller chip(s). Perhaps the modification you mention had to do with the drive jumpers as early drives (before IBM PC became standard) had slightly different interface pin assignments and more configuration options.

 

That being the case, I have several MSD drives and some with dead mechanisms, and I have not been able to find a replacement drive mechanism other than a TEC that would actually work. I have heard of other people doing it, so I believe it's possible but I have not had the time to look into it further.

 

Steve

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sjgray wrote:

 

> I have several MSD drives and some with dead mechanisms, and I have not been able to find a replacement drive mechanism other than a TEC that would actually work. I have heard of other

> people doing it, so I believe it's possible...

 

When Ray Carlsen repaired my MSD SD-1, he replaced all the leaking capacitors and the drive mechanism. He used a Panasonic mech, and it worked perfectly; for some reason, the TEC mechanism was not needed. However, he warned that the MSD SD-2's required the TEC mechanisms; he had tried other mechs, but they didn't work in the SD-2.

 

Prepping for CommVEx,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 2015 -

http://www.portcommodore.com/commvex

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sjgray wrote:

 

> I have several MSD drives and some with dead mechanisms, and I have not been able to find a replacement drive mechanism other than a TEC that would actually work. I have heard of other

> people doing it, so I believe it's possible...

 

When Ray Carlsen repaired my MSD SD-1, he replaced all the leaking capacitors and the drive mechanism. He used a Panasonic mech, and it worked perfectly; for some reason, the TEC mechanism was not needed. However, he warned that the MSD SD-2's required the TEC mechanisms; he had tried other mechs, but they didn't work in the SD-2.

 

Prepping for CommVEx,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 2015 -

http://www.portcommodore.com/commvex

 

That is a bummer. Thankfully all four of my drives are functioning properly. I am about to go through both of them and rip out the old transformer power supplies and replace them with switching supplies, and I will replace caps as I go about it.

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OLD CS1 wrote:

 

> I am about to go through both of them and rip out the old transformer power supplies and replace them with switching supplies...

 

Oh, is something going wrong with the old p.s.'s? Or do you just want something that is more efficient and runs cooler?

 

Prepping for CommVEx,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 2015 --

http://www.portcommodore.com/commvex

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OLD CS1 wrote:

 

> I am about to go through both of them and rip out the old transformer power supplies and replace them with switching supplies...

 

Oh, is something going wrong with the old p.s.'s? Or do you just want something that is more efficient and runs cooler?

 

Prepping for CommVEx,

Robert Bernardo

Fresno Commodore User Group

http://www.dickestel.com/fcug.htm

July 18-19 Commodore Vegas Expo v11 2015 --

http://www.portcommodore.com/commvex

 

 

The latter. Plus the damned things are heavy.

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  • 4 weeks later...

 

Woot!

attachicon.gifmsd sd-2.jpg

 

I found my MSD SD-2s, got them cleaned up and working.

 

I did a little research while I was cleaning them up. Given the schematics, like the 1541 there is no floppy controller chip. All work is done by the 6511Q and its I/O ports, similar to the 1541 and its 6522s. No hope in making the drive double-sided without a good bit of work: it looks like the 6511Q has a free I/O pin or two, so with some wiring and DOS modifications it may be possible to set up a head-select.

 

That aside, one of the things I came across was that MSD made modifications to the TEC (TEAC?) FD-501 to accommodate GCR. None of this is mentioned in the schematics I have.

 

If true, does anyone have information on what had to be modified on the drive?

 

What mods? BTW, these are the same drives in the tandy FD-501

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What mods? BTW, these are the same drives in the tandy FD-501

 

Well, here we go... not the best source of sources, but this must be where I found it as I found no other reference (in my 20 second research session):

 

MSD Super Disk - Wikipedia, the free encyclopedia

"Internally, both models featured TEC brand (model FB-501) floppy drive mechanisms. The electronics on the mechanisms was modified by MSD to be compatible with the GCR recording format used by all Commodore disk drives at the time. The main control board utilized a 1 MHz Rockwell International 6511Q microcontroller."

https://en.wikipedia.org/wiki/MSD_Super_Disk

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  • 3 months later...

I have 3 of these beasts. I repaired one MSD SD-2 that had a capacitor meltdown in one drive. I replaced the drive with a TEC FB-501 purchased on ebay, The one I received on ebay was permanently solder jumpered where the MSD's selectible jumpers were (correct?) so I removed the wires from the pads - placed removable jumpers there and reconfigured it like the stock one and it works like a champ.

 

I saw no obvious physical difference in the two drives other than the jumper area.

 

It has been a while since i fixed it so hopefully my memory is correct. Whatever I did - the jumpers were the only thing at issue. I also have a few more extra FB-501's that I got for a steal - they pop up on ebay from time to time but they are pretty rare at this point it seems.

 

Hope that helps.

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