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Teac FD-235GF 3156-u replacement

G

gcd

Jan 1, 1970
0
Hi all,
I have an Advantest network analyser that uses a Teac FD-235GF 3156-U floppy
drive. Teac cannot/willnot provide any information on the drive or a
suitable teac replacement. They tell me it's a proprietary drive and to
contact Advantest. Advantest won't help either, the analyser is past service
support life.

Anyone have a collection of NOS or even used FD-235GF 3156-U drives I can
buy ( want around 3-5)

Or - anyone have any info on the teac 235-gf apart from the teac.jp website
glossy and any knowledge of a suitable replacement?

If I can determine what the jumper settings mean perhaps I can find another
drive that would suit. Anyone have a copy of the service manual for the
drive that identifies the jumper settings?

The jumper configuration for the drive as installed in the 3762ah is per the
following list.
A1-B1,B4-C4,B3-C3,D4-E4, F1-G1
D1-D2, E2-E3, G3-G4

Any help appreciated

Thanks
Greg
 
B

Baron

Jan 1, 1970
0
gcd said:
Hi all,
I have an Advantest network analyser that uses a Teac FD-235GF 3156-U
floppy
drive. Teac cannot/willnot provide any information on the drive or a
suitable teac replacement. They tell me it's a proprietary drive and
to contact Advantest. Advantest won't help either, the analyser is
past service support life.

Anyone have a collection of NOS or even used FD-235GF 3156-U drives I
can buy ( want around 3-5)

Or - anyone have any info on the teac 235-gf apart from the teac.jp
website glossy and any knowledge of a suitable replacement?

If I can determine what the jumper settings mean perhaps I can find
another drive that would suit. Anyone have a copy of the service
manual for the drive that identifies the jumper settings?

The jumper configuration for the drive as installed in the 3762ah is
per the following list.
A1-B1,B4-C4,B3-C3,D4-E4, F1-G1
D1-D2, E2-E3, G3-G4

Any help appreciated

Thanks
Greg

That could just be a standard PC floppy drive. Teac FD-235's are/used to
be used in IBM compatible PC's. I'm sure I have some kicking around.
I'll have a look on Monday when I get into work.
 
G

gcd

Jan 1, 1970
0
Baron said:
That could just be a standard PC floppy drive. Teac FD-235's are/used to
be used in IBM compatible PC's. I'm sure I have some kicking around.
I'll have a look on Monday when I get into work.


Hi Baron,
the PC drives are FD-235 HF not GF as far as I've been able to identify and
the jumper set is different.

For the most part I reckon all I need is to know the jumper matrix settings,
from there I should be able to sort out modifying any current drive to suit.

However, if you do find some GF drives I would be most interested.

Thanks for the help
Greg
 
L

Larry

Jan 1, 1970
0
Baron said:
That could just be a standard PC floppy drive. Teac FD-235's are/used to
be used in IBM compatible PC's. I'm sure I have some kicking around.
I'll have a look on Monday when I get into work.


Hi Baron,
the PC drives are FD-235 HF not GF as far as I've been able to identify and
the jumper set is different.

For the most part I reckon all I need is to know the jumper matrix settings,
from there I should be able to sort out modifying any current drive to suit.

However, if you do find some GF drives I would be most interested.

Thanks for the help
Greg

***
Do any of these help?

http://www.teac.com/DSPD/pdf/3fd0105a.pdf

http://www.google.com.au/search?num...GGGL_en___AU231&q=FD-235hf+&btnG=Search&meta=

http://www.hkinventory.com/public/O...ry=&postdate=&brand=&crit3=&crit4=0&datecode=

Larry
 
G

gcd

Jan 1, 1970
0
Larry said:
Hi Baron,
the PC drives are FD-235 HF not GF as far as I've been able to identify
and
the jumper set is different.

For the most part I reckon all I need is to know the jumper matrix
settings,
from there I should be able to sort out modifying any current drive to
suit.

However, if you do find some GF drives I would be most interested.

Thanks for the help
Greg

***
Do any of these help?

http://www.teac.com/DSPD/pdf/3fd0105a.pdf

http://www.google.com.au/search?num...GGGL_en___AU231&q=FD-235hf+&btnG=Search&meta=

http://www.hkinventory.com/public/O...ry=&postdate=&brand=&crit3=&crit4=0&datecode=

Larry

Hi Larry,
thanks for the links - unfortunately not much use I'm afraid. I hadn't seen
that pdf on the teac site but as it was about HG to HF differences no
mention of the GF drive.

I'm particularly looking for the GF drive not the HF drive. The jumper pad
on this drive allows for all sorts of non standard pinout configurations
such as density select on pin 6 rather than 2 etc. The problem is some of
these interfaces have changed over time, for example the density select can
be either an input or an output or both depending on the drive and the
controller and without the jumper data I'm not sure how the drive is
actually configured to operate.

The controller on the drive is a T4A34F, again no luck in finding any info
on this chip to allow me to identify what pin goes to what jumper. If anyone
has a datasheet on that teac IC that would also be of some use.

Thanks
Greg
 
G

gcd

Jan 1, 1970
0
Baron said:
Hi Greg,
I've had a look through a number of bits of HP kit ! They are all Teac
FD-235-HF's I'm afraid.
I'm very sorry about that ! I felt sure that I could help. :-(

Hi Baron,
no problems. Thanks for looking though.
I've had some success using a standard pc drive. Had to use DS0 rather than
DS1 (expected) and needed to ensure the drive was using disk change on pin
34. The only thing that is still a little peculiar is the density select and
whether it's an input/output or both. Using a standard PC drive I need to
use a HD disk but cover over the HD hole and that seems to work reliably. On
the original drive I would use HD without covering up the hole. The only
issues I end up with is that the drive light is always 1/2 on when not in
use.

I'll keep looking for FD-235GF data and playing around. i'ts almost sorted
now

Thanks
Greg
 
F

Franc Zabkar

Jan 1, 1970
0
I've had some success using a standard pc drive. Had to use DS0 rather than
DS1 (expected) and needed to ensure the drive was using disk change on pin
34. The only thing that is still a little peculiar is the density select and
whether it's an input/output or both. Using a standard PC drive I need to
use a HD disk but cover over the HD hole and that seems to work reliably. On
the original drive I would use HD without covering up the hole. The only
issues I end up with is that the drive light is always 1/2 on when not in
use.

I'll keep looking for FD-235GF data and playing around. i'ts almost sorted
now

Thanks
Greg

This URL suggests that pin 2 is an input to the drive:
http://pinouts.ru/Storage/InternalDisk_pinout.shtml

I suggest you look at the datasheet for an old multi-IO chip such as
were used on 486 and Pentium motherboards, before the functions were
incorporated into the chipset.

For example, here is the datasheet for a Winbond W83757F:
http://www.datasheetarchive.com/datasheets/Datasheet-022/DSA00379504.pdf

Amongst the FDC pins is RWC, Reduced Write Current. "This signal can
be used on two-speed disk drives to select the transfer rate."

Logic 0 = 250 Kb/s
Logic 1 = 500 Kb/s

It is described as an "open-drain output pin with 24 mA sink
capability".

I've seen this pin used in 2-speed 5.25" drives, but not in 3.5"
drives. It could be that the HD hole in the diskette tells the [PC]
drive what write current to use, but the drive does not report the
diskette type to the controller.

Does your Advantest network analyser write 1.44MB or 720KB of data to
the diskettes? It would seem odd if the drive were writing to the
diskette as if it were a 720KB lo-den type while the controller were
transferring data at a hi-den (500 Kb/s) rate.

Could it be that your current setup is operating at a 250Kb/s data
rate, and that your diskette's capacity is being reduced to 720KB?
Could it be that the original FDD uses the "RWC" pin as an output
rather than an input, and that it communicates the diskette type to
the analyser, in which case the analyser could automatically adjust
the data rate to suit??? In the latter case, if the analyser doesn't
get any feedback from the drive, perhaps it defaults to a lo-den data
rate. You might like to experiment with a pull-down or pullup resistor
on this pin.

- Franc Zabkar
 
F

Franc Zabkar

Jan 1, 1970
0
such as density select on pin 6 rather than 2 etc. The problem is some of
these interfaces have changed over time, for example the density select can
be either an input or an output or both depending on the drive and the
controller and without the jumper data I'm not sure how the drive is
actually configured to operate.

FWIW, this document refers to FD55-GFR 5.25" drives:
http://www.teac.com/DSPD/pdf/5fd0050a.pdf

There is an LG strap and an I strap that define how the drive behaves
in lo-den and hi-den modes.
The controller on the drive is a T4A34F, again no luck in finding any info
on this chip to allow me to identify what pin goes to what jumper. If anyone
has a datasheet on that teac IC that would also be of some use.

Thanks
Greg

- Franc Zabkar
 
F

Franc Zabkar

Jan 1, 1970
0
FWIW, this document refers to FD55-GFR 5.25" drives:
http://www.teac.com/DSPD/pdf/5fd0050a.pdf

There is an LG strap and an I strap that define how the drive behaves
in lo-den and hi-den modes.

There is also an In-Use (IU) jumper set that defines the conditions
under which the in-use LED turns on. The standard jumpering for a PC
AT system is to illuminate the LED whenever Drive Select is active,
whether or not the drive is actually doing anything. Is it possible
that the controller is constantly checking the DiskChange pin and
thereby activating the LED?

- Franc Zabkar
 
G

gcd

Jan 1, 1970
0
Franc Zabkar said:
There is also an In-Use (IU) jumper set that defines the conditions
under which the in-use LED turns on. The standard jumpering for a PC
AT system is to illuminate the LED whenever Drive Select is active,
whether or not the drive is actually doing anything. Is it possible
that the controller is constantly checking the DiskChange pin and
thereby activating the LED?

- Franc Zabkar

Hi again Franc,
I've been across all the jumpers on the drive I'm playing with and none
appear to affect the dim led. it goes off but I'll keep playing around if I
can't find the info I'm after

Cheers
Greg
 
G

gcd

Jan 1, 1970
0
Franc Zabkar said:
I've had some success using a standard pc drive. Had to use DS0 rather
than
DS1 (expected) and needed to ensure the drive was using disk change on
pin
34. The only thing that is still a little peculiar is the density select
and
whether it's an input/output or both. Using a standard PC drive I need to
use a HD disk but cover over the HD hole and that seems to work reliably.
On
the original drive I would use HD without covering up the hole. The only
issues I end up with is that the drive light is always 1/2 on when not in
use.

I'll keep looking for FD-235GF data and playing around. i'ts almost sorted
now

Thanks
Greg

This URL suggests that pin 2 is an input to the drive:
http://pinouts.ru/Storage/InternalDisk_pinout.shtml

I suggest you look at the datasheet for an old multi-IO chip such as
were used on 486 and Pentium motherboards, before the functions were
incorporated into the chipset.

For example, here is the datasheet for a Winbond W83757F:
http://www.datasheetarchive.com/datasheets/Datasheet-022/DSA00379504.pdf

Amongst the FDC pins is RWC, Reduced Write Current. "This signal can
be used on two-speed disk drives to select the transfer rate."

Logic 0 = 250 Kb/s
Logic 1 = 500 Kb/s

It is described as an "open-drain output pin with 24 mA sink
capability".

I've seen this pin used in 2-speed 5.25" drives, but not in 3.5"
drives. It could be that the HD hole in the diskette tells the [PC]
drive what write current to use, but the drive does not report the
diskette type to the controller.

Does your Advantest network analyser write 1.44MB or 720KB of data to
the diskettes? It would seem odd if the drive were writing to the
diskette as if it were a 720KB lo-den type while the controller were
transferring data at a hi-den (500 Kb/s) rate.

Could it be that your current setup is operating at a 250Kb/s data
rate, and that your diskette's capacity is being reduced to 720KB?
Could it be that the original FDD uses the "RWC" pin as an output
rather than an input, and that it communicates the diskette type to
the analyser, in which case the analyser could automatically adjust
the data rate to suit??? In the latter case, if the analyser doesn't
get any feedback from the drive, perhaps it defaults to a lo-den data
rate. You might like to experiment with a pull-down or pullup resistor
on this pin.

- Franc Zabkar


Hi Franc,
yes - pin 2 determines the density of the drive which is usally related to
the speed of the drive. Some fdc chips expect this to be sent to the dhip
from the drive, some expect to send it out to the drive and others are
bi-directional. Just depends on the age of the drive and the controller, as
things changed from shugart to pc format interface.

This is why I'd like to get the jumper info - it would tell all.

I've had a bit of play with pull ups with no luck but I'll persist :)

Thanks for the links and suggestions, mind you, if all I end up with is a
light 1/2 on I can live with that - just need to ensure the configuration i
end up with is reliable in terms of data storage


Greg
 
B

Baron

Jan 1, 1970
0
gcd Inscribed thus:
DS1 (Drive Select) was the result of some bright spark realising that a
twist in the cable could be used to determine which drive was "A" In
practice it probably saved a lot of money for the manufacturers and
confused techies !

It sticks in my mind that it was always an output in the sense that it
was used to detect the difference between 720/144 Mb disks and set the
rotational speed, 300/360 rpm I belive.

I wonder if that is anything to do with difference in the material used
for the magnetic coating.
 
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