Converting from 8 to 3.5 inch floppy diskettes

[marcus bennett]

Dear All,

Get ready to use 3.5 inch diskette drives instead of those big and
noisy 8 inch drives

http://majzel.blogspot.com/2009/04/converting-from-8-to-35-inch-floppy.html

Regards marcus.

[Keith]

Nice work Marcus. I purchased four of these drives when you mentioned
the option these had of density three and is needed as you pointed
out. I have the same model number but the circuit board is slightly
different. The circuit board does NOT run along both side of the motor
as in your pictures. With your pictures I was able to find the OPA
pads and make the changes as you have and it does work great as drive
B now. Being a CP/M fan I had to make a cable that swapped select
lines 0 and 1 to boot CP/M as drive A. CP/M is weird and requires it
to boot as drive A with this image. No pictures of my cable as you
provided as it is a real mess but does now boot CP/M as drive A and is
VERY fast. I was able to copy files on the Marcus drive with 22disk
and then read them with CP/M

Question Marcus. Does you PCB show where you can make the changes to
revert it to normal drive A and not like all other 3 1/5 drives hard
wired for drive B?
It would be great to make the changes to allow drive C or D. The lines
are there so worst case is you could make a ugly cable.

Thanks for the tips.

On Apr 16, 9:42 am, marcus bennett <amou...@gmail.com> wrote:
> Dear All,
>
> Get ready to use 3.5 inch diskette drives instead of those big and
> noisy 8 inch drives
>

> http://majzel.blogspot.com/2009/04/converting-from-8-to-35-inch-flopp...
>
> Regards marcus.

[Marcus Bennett]

Keith,

Some random comments ...  (some a little off topic)

I found out today that you need CDOS > 2.36 in order to boot to a non A: drive.  It's todo with the boot program that you place in the boot area with wrtsys.  Clearly it must have changed it since at say 02.53 with which I have no trouble booting from  any drive.

Next ... PCB .  Yes I remember seeing a DS1 with a solder blob on it and nearby a DS0 and DS-others as I recall. Presumably one needs to solder up DS0 and unsolder DS1 to select it as A:.  (Dont forget on the blog you can always click on the photo to get the high res source picture )

Personally I am absolutely thrilled that the 3.5 drive is working. No more scouring ebay for 5.25 HD diskettes.  The last box that I had bought on eBay , upon opening turned out to have "Gateshead College" on the media and not memorex as the box indicated.  And they were 360K not 1.2M  The git who sold me them must have put them in there then shrink wrapped it with a personal tool.   Some people eh!

And even more off topic ... Anybody have a maximiser board, because I just got the software for it!

Good night

2009/4/16 Keith <khar...@gmail.com>

--
marcus bennett    amo...@gmail.com

[Keith]

On Apr 16, 6:18 pm, Marcus Bennett <amou...@gmail.com> wrote:
> Keith,
>
> Some random comments ...  (some a little off topic)
>
> I found out today that you need CDOS > 2.36 in order to boot to a non A:
> drive.  It's todo with the boot program that you place in the boot area with
> wrtsys.  Clearly it must have changed it since at say 02.53 with which I
> have no trouble booting from  any drive.
>
> Next ... PCB .  Yes I remember seeing a DS1 with a solder blob on it and
> nearby a DS0 and DS-others as I recall. Presumably one needs to solder up
> DS0 and unsolder DS1 to select it as A:.  (Dont forget on the blog you can
> always click on the photo to get the high res source picture )
>
> Personally I am absolutely thrilled that the 3.5 drive is working. No more
> scouring ebay for 5.25 HD diskettes.  The last box that I had bought on eBay
> , upon opening turned out to have "Gateshead College" on the media and not
> memorex as the box indicated.  And they were 360K not 1.2M  The git who sold
> me them must have put them in there then shrink wrapped it with a personal
> tool.   Some people eh!
>
> And even more off topic ... Anybody have a maximiser board, because I just
> got the software for it!
>
> Good night
>

> 2009/4/16 Keith <kharr...@gmail.com>
>
>
You are right. You can boot B drive with a later RDOS. I forgot I had
a very old 16FDC(2.01) card in that machine. Thanks. There still
appears to be a number of different PCB on floppy drive due to where
and when it was made. It's a great floppy with a lot of options.

> marcus bennett    amou...@gmail.com

You are right. You can boot B drive with a later RDOS. I forgot I had
a very old 16FDC(2.01) card in that machine. Thanks. There still
appears to be a number of different PCB on the floppy drive due to
where and when it was made. It's a great floppy with a lot of options.
I picked up a few more just to see what the PCB would look like. I
have looked under a eye glass and don't see any ds0-ds1 pads where
your picture shows them. I could just rework the pins on the connector
and not build a bunch of cables with different wired connectors. Hope
the new ones are like yours.
I have spent a lot of time cleaning drive heads on 8" drives while
going through old floppies not to mention the cost of buying new ones.
My plan is to use 3 1/2 as my work drives a-c and maybe a 5 1/4. I'm
done with using 8" on a daily bases anymore. I just finished running
disk which is a disk test program 200 times with ZERO errors on the
drive with the mod. Let the other folks debate the techs different I'm
sold with cost,speed,shipping and moving data around between PCs and
Cromemco assuming you have 22disk or something like that.

[Bill Sudbrink]

marcus bennett wrote:
> Get ready to use 3.5 inch diskette drives instead of those big and
> noisy 8 inch drives

Well, I like 8 inch floppies (maybe there's something wrong with me).
Anyway, I wonder whether the same modification could be made to one
of those combo-3.5-5.25 units. You could get the storage of four
8-inch floppies in the space of one 5.25 full height unit.

> http://majzel.blogspot.com/2009/04/converting-from-8-to-35-inch-floppy.html
>
> Regards marcus.

[Keith]

> >http://majzel.blogspot.com/2009/04/converting-from-8-to-35-inch-flopp...
>
> > Regards marcus.
>
> I have uploaded picture of the floppy drive I have from egghead($7.00). The model number is the same and it works but the PCB is a little different.

[MdntTrain]

On Apr 16, 4:55 pm, Keith <kharr...@gmail.com> wrote:
> Nice work Marcus. I purchased four of these drives when you mentioned
> the option these had of density three and is needed as you pointed
> out. I have the same model number but the circuit board is slightly
> different.

I bought 2 of these drives and was sorely disappointed to discover
they're quite different from Marcus' photos. These are cheap junk
whereas the one in Marcus' photo looks much better. I'm sorry I
wasted the money.. but now that I have them....

See page 25 of the 31 page SFD-321B .pdf Marcus provides.. it tells
you how to decode the serial number. Mine is FBTA S1AU5xxxxx Rev.
TA. The PCB is Rev WT-10S 2.1. The only difference from the
example in the manual is that mine is minor rev A vs. minor rev 6.
Seems like a major rev difference to me.

Marcus, what serial # do you have? Keith, what is yours?

Mine has no DS select pads, and though I can see OPA and OPB lettered,
it's not clear at all what pads are associated. My OPA and OPB are
right next to each other.. 90 degree angle between them. There are 4
pads right there but no visible marking associating them. Compared
to the Mitsumi D359T3 or Teac FD235HG, this drive is frustrating the
s**t out of me. lol.

jS

[Keith]

On Apr 21, 8:52 pm, MdntTrain <j...@cimmeri.com> wrote:
> On Apr 16, 4:55 pm, Keith <kharr...@gmail.com> wrote:
>
> > Nice work Marcus. I purchased four of these drives when you mentioned
> > the option these had of density three and is needed as you pointed
> > out. I have the same model number but the circuit board is slightly
> > different.
>
> I bought 2 of these drives and was sorely disappointed to discover
> they're quite different from Marcus' photos.   These are cheap junk
> whereas the one in Marcus' photo looks much better.   I'm sorry I
> wasted the money.. but now that I have them....
>
> See page 25 of the 31 page SFD-321B .pdf Marcus provides.. it tells
> you how to decode the serial number.   Mine is FBTA S1AU5xxxxx Rev.
> TA.   The PCB is Rev WT-10S 2.1.    The only difference from the
> example in the manual is that mine is minor rev A vs. minor rev 6.
> Seems like a major rev difference to me.
>
> Marcus, what serial # do you have?  Keith, what is yours?
>

FBTA S1BU50330610 REV.TA
SFD-312B /LFBL1

> Mine has no DS select pads, and though I can see OPA and OPB lettered,
> it's not clear at all what pads are associated.  My OPA and OPB are
> right next to each other.. 90 degree angle between them.  There are 4
> pads right there but no visible marking associating them.    Compared
> to the Mitsumi D359T3 or Teac FD235HG, this drive is frustrating the
> s**t out of me. lol.

I would agree on DS0-DS1 swap on the PCB. I followed Pin 10 which is
DS0 and it doesn't connect on the PCB at all. I made the swap at the
connector swapping PINs 10 and 12. I removed the black plastic cable
guide and swapped the pin position and replaced the plastic connector
making sure not the have the pins touch at the swap point.

Does the manual show where the density selection pads are on the PCB
for the Teac?
>
>  jS

[kharrell]

I can send you a picture of my jumpers if you want. I purchased four of
these drives and three work great. The fourth one is laying out in the
yard. It looks like it was throw out a open window. Maybe it was bad
before I started or maybe I smoked it. Whats the saying
Smoke them if you got them.

[MdntTrain]

On Apr 22, 10:15 am, Keith <kharr...@gmail.com> wrote:

> FBTA S1BU50330610 REV.TA
> SFD-312B /LFBL1

Ok, so we have the same drive, just made at different factories.

> I made the swap at the
> connector swapping PINs 10 and 12. I removed the black plastic cable
> guide and swapped the pin position and replaced the plastic connector
> making sure not the have the pins touch at the swap point.

Interesting way to do it.. sounds tricky. I think I'd just cut the
trace on the PCB and wire over from the other pin.

> Does the manual show where the density selection pads are on the PCB
> for the Teac?

The drive works differently. It logically-enough assumes that if you
have an HD diskette in the drive, and if pin 2 is low, to use the
1.6MB. If pin 2 is high, it goes to 2.0MB. When a DD diskette is
in drive, it knows it could only be the 800k mode.

jS

[MdntTrain]

Harrell, do you have the same drive version as Keith and I?

Sure, if you can upload your pic to the Files section of this group,
that'd at least save me, possibly others, time screwing around.

jS

[Keith]

On Apr 22, 2:02 pm, MdntTrain <j...@cimmeri.com> wrote:
> Harrell, do you have the same drive version as Keith and I?

Sorry I'm one of the same. I email sometime and it posts as kharrell
I'll upload a picture of my PCB with the mods.

[Keith]

I have just received two more Samsung drive with white face plate and
these are the same as Marcus pictures. They have DS0,DS1,DS3 contact
pads and all the others pads needed. These also have two plates on the
top and bottom which have to be removed which the other one's only had
one. The PCB also runs down both sides on the motor. These seem to be
better quality then the other ones from egghead.
I got these from
http://www.alancomputech.com/sfd-321b-knec.html
Note the KNEC at the end. They offer two models. These are refurbished
but look new. They are $7.00 but shipping is higher?

[MdntTrain]

On Apr 23, 10:41 am, Keith <kharr...@gmail.com> wrote:
> I have just received two more Samsung drive with white face plate and
> these are the same as Marcus pictures.

What's the serial number on these?

[kharrell]

The Serial number is
FBT1 P4CK944334 REV T2

[MdntTrain]

On Apr 22, 4:19 pm, Keith <kharr...@gmail.com> wrote:
> I'll upload a picture of my PCB with the mods.

Nice photos. Thanks very much for taking the time to do that.

On #60, man, where you soldered the OPA black wire on the left, I
thought those two *might* have been the OPA pads.. but saw that
they're already bridged. I hadn't thought that tiny pad under the
black wire as the other OPA pad.. geeze, that's small.

Are those two pads actually OPB? Or is OPB the one on left and one
*down* from it?

I presume the HD0 zero pads are the two right under "HD0"

jS