Help! 5.25" drive must be alone to work!

[Jim Jones]

Jim Jones wrote:


Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.misc Folkert Rienstra


[...]

If you're not sure about yours, do a Google search for each
drive's brand and model number and "jumper," to see if yours
are set correctly for the position you want each in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to respond to
drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB 3.5").
And I have seen a newer one as well somewhere. Not all 3.5" floppies
are designed for PC use only. The Shuggart-bus definitely supports
4 floppies. I think the design with the twisted cable was just to
make it idiot-proof. So no surprise Rod does not know about this ;-)

How odd that I've actually commented on it in the past and
even a pathetic excuse for a troll could find it in groups.google.

Not so much "idiot proof" as easier to assemble. With jumpers you
either have to have two bins of drives or you have to have the guy on
the line set
the jumpers each time. Either of these will increase manufacturing
cost due to rework--with the jumpers he'll set them incorrectly from
time no matter how diligent he is, to time, with the preconfigured
drives they'll
get binned incorrectly from time to time. With the twisted cable you
only have to maintain one bin of identically jumpered drives,
eliminating that source of manufacturing errors, at the cost of a
slightly more expensive cable that can be easily inspected.

Pity there have been bugger all PCs shipped with
more than one floppy drive for years and years
now, and even less with two identical floppy drives.

Nice theory. Pity about the reality tho.

The reality is that the twisted cable was use for both diskette and hard
drives
Duh.

and it was put into use in the era in which
dual diskette drives were the norm.
Nope.

Nope?

Nope.

I see.

You dont.

So would you be kind enough to provide the date on which
machines with dual diskette drives ceased to be commonplace
and the date on which IBM introduced the twisted diskette cable?

YOU made that claim. YOU get to provide the
substantiation for that claim. THATS how it works.

So what was the reason?

Its basically simpler to have the drives jumpered
the same way all the time and control the letter the
drive gets by the connector its plugged into. The
same rationale as with cable select and ATA drives.

Quite a few motherboard bios have
an A/B swap in the bios as well.

The first IDE implementations preceded the existence of any standard.

Duh. I never said anything about any standard.

 

[Rod Speed]

"J. Clarke" (e-mail address removed)> wrote in message Arno Wagner wrote:
"Rod Speed" (e-mail address removed)> wrote in message
[...]

If you're not sure about yours, do a Google search for each
drive's brand and model number and "jumper," to see if yours
are set correctly for the position you want each in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to respond to
drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB 3.5").
And I have seen a newer one as well somewhere. Not all 3.5" floppies
are designed for PC use only. The Shuggart-bus definitely supports
4 floppies. I think the design with the twisted cable was just to
make it idiot-proof. So no surprise Rod does not know about this ;-)

How odd that I've actually commented on it in the past and
even a pathetic excuse for a troll could find it in groups.google.

Not so much "idiot proof" as easier to assemble. With jumpers you either
have to have two bins of drives or you have to have the guy on the line
set
the jumpers each time. Either of these will increase manufacturing cost
due to rework--with the jumpers he'll set them incorrectly from time no
matter how diligent he is, to time, with the preconfigured drives they'll
get binned incorrectly from time to time. With the twisted cable you
only have to maintain one bin of identically jumpered drives, eliminating
that source of manufacturing errors, at the cost of a slightly more
expensive cable that can be easily inspected.

Pity there have been bugger all PCs shipped with
more than one floppy drive for years and years
now, and even less with two identical floppy drives.

Nice theory. Pity about the reality tho.

The reality is that the twisted cable was use for both diskette and hard
drives

It was?

Yep, with MFM, RLL and ESDI drives that were current at
the time that twisted cable approach showed up with floppys.

IDE never needed a twist. Cable select has nothing to do with a twist.

Wrong. Those are two different ways of achieving the
same effect, the drive ID being determined by the drive
connector used. Instead of having to fiddle with jumpers.

IDE doesn't even have a specific device select line. IDE devices react
to a register delivered ID (0/1). And even a twist to avoid nipping
a wire doesn't work as pin 27 (2 wire twist) is a used signal and both
26 and 30 (3 wire twist) are ground, similar to CSEL (pin28)
The floppy wire twist involves 7 wires, not just 2 (or 3).

No news.

 

[Rod Speed]

In comp.sys.ibm.pc.hardware.misc Folkert Rienstra <[email protected]>
wrote:

"Rod Speed" (e-mail address removed)> wrote in message
[...]

If you're not sure about yours, do a Google search for each
drive's brand and model number and "jumper," to see if yours
are set correctly for the position you want each in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to respond to
drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB 3.5").
And I have seen a newer one as well somewhere. Not all 3.5" floppies
are designed for PC use only. The Shuggart-bus definitely supports
4 floppies. I think the design with the twisted cable was just to
make it idiot-proof. So no surprise Rod does not know about this ;-)

Not so much "idiot proof" as easier to assemble. With jumpers you either
have to have two bins of drives or you have to have the guy on the line set
the jumpers each time. Either of these will increase manufacturing cost
due to rework--with the jumpers he'll set them incorrectly from time no
matter how diligent he is, to time, with the preconfigured drives they'll
get binned incorrectly from time to time.

With the twisted cable you only have to main-
tain one bin of identically jumpered drives,

To use jumperless PC-type drives that have drive select fixed at pin 12.

Jumperless floppy drives came much later, once
there was no longer any point in changing the
jumpers with the vast bulk of floppy drives sold.

 

[J. Clarke]

Jim Jones wrote:


Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.misc Folkert Rienstra


[...]

If you're not sure about yours, do a Google search for each
drive's brand and model number and "jumper," to see if yours
are set correctly for the position you want each in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to respond
to drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB 3.5").
And I have seen a newer one as well somewhere. Not all 3.5"
floppies are designed for PC use only. The Shuggart-bus
definitely supports 4 floppies. I think the design with the
twisted cable was just to make it idiot-proof. So no surprise Rod
does not know about this ;-)

How odd that I've actually commented on it in the past and
even a pathetic excuse for a troll could find it in groups.google.

Not so much "idiot proof" as easier to assemble. With jumpers you
either have to have two bins of drives or you have to have the guy
on the line set
the jumpers each time. Either of these will increase manufacturing
cost due to rework--with the jumpers he'll set them incorrectly
from time no matter how diligent he is, to time, with the
preconfigured drives they'll
get binned incorrectly from time to time. With the twisted cable
you only have to maintain one bin of identically jumpered drives,
eliminating that source of manufacturing errors, at the cost of a
slightly more expensive cable that can be easily inspected.

Pity there have been bugger all PCs shipped with
more than one floppy drive for years and years
now, and even less with two identical floppy drives.

Nice theory. Pity about the reality tho.

The reality is that the twisted cable was use for both diskette and
hard drives

Duh.

and it was put into use in the era in which
dual diskette drives were the norm.

Nope.

Nope?

Nope.

I see.

You dont.

So would you be kind enough to provide the date on which
machines with dual diskette drives ceased to be commonplace
and the date on which IBM introduced the twisted diskette cable?

YOU made that claim. YOU get to provide the
substantiation for that claim. THATS how it works.

Fine, I remember personally repairing many machines with dual diskette
drives and twisted cables.

Your ball.

Its basically simpler to have the drives jumpered
the same way all the time and control the letter the
drive gets by the connector its plugged into.

I see. So who made the decision to simplify everyone's life in this fashion?
And do you have proof of any kind that your assertion is true or are you
just speculating?

The
same rationale as with cable select and ATA drives.

Quite a few motherboard bios have
an A/B swap in the bios as well.


Duh. I never said anything about any standard.

Well, now, prior to the standard most ide implementations didn't even work
with other drives of the same brand, so I think we can pretty well discount
that as a learning period.

 

[Robert Nichols]

:> Its basically simpler to have the drives jumpered
:> the same way all the time and control the letter the
:> drive gets by the connector its plugged into.
:
:I see. So who made the decision to simplify everyone's life in this fashion?
:And do you have proof of any kind that your assertion is true or are you
:just speculating?

Apparently it was an IBM-ism from "way back when ..." . I dug into my
musty old book pile and found a 1988 copy of The Winn Rosch Hardware
Bible, wherein the chapter on floppy disks states:

"With IBM products, drive select settings have no relevance. All
floppy disk drives in an IBM-style computer are set to be the
second drive in the system. A special twist to the floppy disk
connecting cable sorts out the proper disk drive's identity."

Note that in the above book, the 80386 and the IBM PS/2 were
considered "State of the Art" for personal computers.

 

[Jim Jones]

Jim Jones wrote:


Jim Jones wrote:


Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.misc Folkert Rienstra


[...]

If you're not sure about yours, do a Google search for each
drive's brand and model number and "jumper," to see if yours
are set correctly for the position you want each in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to respond
to drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB 3.5").
And I have seen a newer one as well somewhere. Not all 3.5"
floppies are designed for PC use only. The Shuggart-bus
definitely supports 4 floppies. I think the design with the
twisted cable was just to make it idiot-proof. So no surprise Rod
does not know about this ;-)

How odd that I've actually commented on it in the past and
even a pathetic excuse for a troll could find it in groups.google.

Not so much "idiot proof" as easier to assemble. With jumpers you
either have to have two bins of drives or you have to have the guy
on the line set
the jumpers each time. Either of these will increase manufacturing
cost due to rework--with the jumpers he'll set them incorrectly
from time no matter how diligent he is, to time, with the
preconfigured drives they'll
get binned incorrectly from time to time. With the twisted cable
you only have to maintain one bin of identically jumpered drives,
eliminating that source of manufacturing errors, at the cost of a
slightly more expensive cable that can be easily inspected.

Pity there have been bugger all PCs shipped with
more than one floppy drive for years and years
now, and even less with two identical floppy drives.

Nice theory. Pity about the reality tho.

The reality is that the twisted cable was use for both diskette and
hard drives

Duh.

and it was put into use in the era in which
dual diskette drives were the norm.

Nope.

Nope?

Nope.

I see.

You dont.

So would you be kind enough to provide the date on which
machines with dual diskette drives ceased to be commonplace
and the date on which IBM introduced the twisted diskette cable?

YOU made that claim. YOU get to provide the
substantiation for that claim. THATS how it works.

Fine, I remember personally repairing many machines
with dual diskette drives and twisted cables.

Separate issue entirely to 'the norm'

Your ball.

Nope, still yours.

I see. So who made the decision to simplify everyone's life in this fashion?

Pretty sure it was IBM. They basically just started doing
it that way, as part of the process which involved cleaning
up quite a bit of the detail in the original IBM PC that never
did get used much like the cassette interface etc and a
rather more complete rethink of the basics like the drive
tables in the motherboard cmos that came with the AT etc.

And do you have proof of any kind that your
assertion is true or are you just speculating?

Nope, its fact that the original IBM PC didnt use
a floppy cable with a twist and the later ones did.
You can see that spelt out in the Tech Ref manuals.

Presumably those are available online now, havent
bothered to look. I've still got the printed originals.

The clones of that era were very close clones on the
whole, often right down to the use of the same IC
numbers in the schematics, tho with often a higher
level of integration with more on each card etc.

Well, now, prior to the standard most ide implementations
didn't even work with other drives of the same brand,

Thats overstating it considerably.

so I think we can pretty well discount that as a learning period.

Irrelevant to that question of a twist in the cable being discussed.

MFM, RLL and ESDI werent formal standards either.

 

[Rod Speed]

:> Its basically simpler to have the drives jumpered
:> the same way all the time and control the letter the
:> drive gets by the connector its plugged into.
:
:I see. So who made the decision to simplify everyone's life in this fashion?
:And do you have proof of any kind that your assertion is true or are you
:just speculating?

Apparently it was an IBM-ism from "way back when ..." . I dug into my
musty old book pile and found a 1988 copy of The Winn Rosch Hardware
Bible, wherein the chapter on floppy disks states:

"With IBM products, drive select settings have no relevance. All
floppy disk drives in an IBM-style computer are set to be the
second drive in the system. A special twist to the floppy disk
connecting cable sorts out the proper disk drive's identity."

Thats overstating it. The original IBM PC didnt use
a floppy cable with a twist and neither did the XT.

Note that in the above book, the 80386 and the IBM PS/2
were considered "State of the Art" for personal computers.

Yes, the twist had become universal by then for floppy cables.

 

[J. Clarke]

Jim Jones wrote:


Jim Jones wrote:


Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.misc Folkert Rienstra


[...]

If you're not sure about yours, do a Google search for
each drive's brand and model number and "jumper," to see
if yours are set correctly for the position you want each
in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to
respond to drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB
3.5"). And I have seen a newer one as well somewhere. Not all
3.5" floppies are designed for PC use only. The Shuggart-bus
definitely supports 4 floppies. I think the design with the
twisted cable was just to make it idiot-proof. So no surprise
Rod does not know about this ;-)

How odd that I've actually commented on it in the past and
even a pathetic excuse for a troll could find it in
groups.google.

Not so much "idiot proof" as easier to assemble. With jumpers
you either have to have two bins of drives or you have to have
the guy on the line set
the jumpers each time. Either of these will increase
manufacturing cost due to rework--with the jumpers he'll set
them incorrectly from time no matter how diligent he is, to
time, with the preconfigured drives they'll
get binned incorrectly from time to time. With the twisted
cable you only have to maintain one bin of identically jumpered
drives, eliminating that source of manufacturing errors, at the
cost of a slightly more expensive cable that can be easily
inspected.

Pity there have been bugger all PCs shipped with
more than one floppy drive for years and years
now, and even less with two identical floppy drives.

Nice theory. Pity about the reality tho.

The reality is that the twisted cable was use for both diskette and
hard drives

Duh.

and it was put into use in the era in which
dual diskette drives were the norm.

Nope.

Nope?

Nope.

I see.

You dont.

So would you be kind enough to provide the date on which
machines with dual diskette drives ceased to be commonplace
and the date on which IBM introduced the twisted diskette cable?

YOU made that claim. YOU get to provide the
substantiation for that claim. THATS how it works.

Fine, I remember personally repairing many machines
with dual diskette drives and twisted cables.

Separate issue entirely to 'the norm'

It does not have to be "the norm" for it to result in savings in
manufacturing cost.

Nope, still yours.

I suspect that providing you with signed statements by the engineers at IBM
who were responsible for the decision would not induce you to accept the
ball.

Pretty sure it was IBM. They basically just started doing
it that way, as part of the process which involved cleaning
up quite a bit of the detail in the original IBM PC that never
did get used much like the cassette interface etc and a
rather more complete rethink of the basics like the drive
tables in the motherboard cmos that came with the AT etc.

And if when the twisted cable was introduced machines seldom had two drives
then why would IBM be willing to pay the slight premium for the twisted
cable? What would be the benefit to them? If the machines all have only
one drive then they're all jumpered identically anyway so what difference
does it make?

Nope, its fact that the original IBM PC didnt use
a floppy cable with a twist and the later ones did.
You can see that spelt out in the Tech Ref manuals.

Who said anything about the original IBM PC? Can you say "straw man"?

Presumably those are available online now, havent
bothered to look. I've still got the printed originals.

The clones of that era were very close clones on the
whole, often right down to the use of the same IC
numbers in the schematics, tho with often a higher
level of integration with more on each card etc.

Try a slightly later era.

Thats overstating it considerably.

Not really.

Irrelevant to that question of a twist in the cable being discussed.

MFM, RLL and ESDI werent formal standards either.

The cabling was.

 

[J. Clarke]

:> Its basically simpler to have the drives jumpered
:> the same way all the time and control the letter the
:> drive gets by the connector its plugged into.
:
:I see. So who made the decision to simplify everyone's life in this
:fashion? And do you have proof of any kind that your assertion is true or
:are you just speculating?

Apparently it was an IBM-ism from "way back when ..." . I dug into my
musty old book pile and found a 1988 copy of The Winn Rosch Hardware
Bible, wherein the chapter on floppy disks states:

"With IBM products, drive select settings have no relevance. All
floppy disk drives in an IBM-style computer are set to be the
second drive in the system. A special twist to the floppy disk
connecting cable sorts out the proper disk drive's identity."

Note that in the above book, the 80386 and the IBM PS/2 were
considered "State of the Art" for personal computers.

I'm not sure of your point--if you read the thread you will see that the
assertion has been made that the original IBM PC did not have the twisted
cable--the discussion is over the reason that the twisted cable was adopted
instead of using jumpered drives. My contention is that it was to reduce
manufacturing costs, the other guy's contention is that it was just "to
make everybody's life simpler".

 

[Jim Jones]

Jim Jones wrote:


Jim Jones wrote:


Jim Jones wrote:


Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.misc Folkert Rienstra


[...]

If you're not sure about yours, do a Google search for
each drive's brand and model number and "jumper," to see
if yours are set correctly for the position you want each
in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to
respond to drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB
3.5"). And I have seen a newer one as well somewhere. Not all
3.5" floppies are designed for PC use only. The Shuggart-bus
definitely supports 4 floppies. I think the design with the
twisted cable was just to make it idiot-proof. So no surprise
Rod does not know about this ;-)

How odd that I've actually commented on it in the past and
even a pathetic excuse for a troll could find it in
groups.google.

Not so much "idiot proof" as easier to assemble. With jumpers
you either have to have two bins of drives or you have to have
the guy on the line set
the jumpers each time. Either of these will increase
manufacturing cost due to rework--with the jumpers he'll set
them incorrectly from time no matter how diligent he is, to
time, with the preconfigured drives they'll
get binned incorrectly from time to time. With the twisted
cable you only have to maintain one bin of identically jumpered
drives, eliminating that source of manufacturing errors, at the
cost of a slightly more expensive cable that can be easily
inspected.

Pity there have been bugger all PCs shipped with
more than one floppy drive for years and years
now, and even less with two identical floppy drives.

Nice theory. Pity about the reality tho.

The reality is that the twisted cable was use for both diskette and
hard drives

Duh.

and it was put into use in the era in which
dual diskette drives were the norm.

Nope.

Nope?

Nope.

I see.

You dont.

So would you be kind enough to provide the date on which
machines with dual diskette drives ceased to be commonplace
and the date on which IBM introduced the twisted diskette cable?

YOU made that claim. YOU get to provide the
substantiation for that claim. THATS how it works.

Fine, I remember personally repairing many machines
with dual diskette drives and twisted cables.

Separate issue entirely to 'the norm'

It does not have to be "the norm" for it to
result in savings in manufacturing cost.

I just commented on your 'the norm' there.

I suspect that providing you with signed statements
by the engineers at IBM who were responsible for
the decision would not induce you to accept the ball.

Its obvious that you should be able to do much better than that.

And if when the twisted cable was introduced machines seldom had two drives

No if about that particular point given that the IBM PC which
was the only one that ever shipped with a significant number
of duplicated floppy drives didnt use a twisted floppy cable.

Even the XT didnt use a twisted floppy cable when made by IBM.

then why would IBM be willing to pay the slight premium
for the twisted cable? What would be the benefit to them?

Like I said, that was the result of a general cleanup of the detail
with the AT. Which hardly ever shipped with duplicate floppy drives.

If the machines all have only one drive then they're all jumpered
identically anyway so what difference does it make?

You'd better ask whoever it was that made that change.

It clearly cant have been for that manufacturing convenience
when the first of the PCs shipped by IBM with a twisted floppy
cable almost never was shipped with duplicated floppy drives.

Who said anything about the original IBM PC?

It happened to be one of the models that didnt use
a twisted floppy cable. And happened to be the only
model that was ever shipped in significant numbers
with duplicated floppy drives. Even the XT didnt.

Can you say "straw man"?

Even you should be able to bullshit your way out of your
predicament better than that pathetic excuse for bullshit.

Try a slightly later era.

Crap, that was what was seen right from the start with true clones.

Not really.

Corse it is.

The cabling was.

Crap. The cabling was determined by the drive it was first used on.

And the use of a twisted control cable wasnt anything like universal either.

 

[J. Clarke]

Jim Jones wrote:


Jim Jones wrote:


Jim Jones wrote:


Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.misc Folkert Rienstra


[...]

If you're not sure about yours, do a Google search for
each drive's brand and model number and "jumper," to
see if yours are set correctly for the position you
want each in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to
respond to drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB
3.5"). And I have seen a newer one as well somewhere. Not
all 3.5" floppies are designed for PC use only. The
Shuggart-bus definitely supports 4 floppies. I think the
design with the twisted cable was just to make it
idiot-proof. So no surprise Rod does not know about this
;-)

How odd that I've actually commented on it in the past and
even a pathetic excuse for a troll could find it in
groups.google.

Not so much "idiot proof" as easier to assemble. With
jumpers you either have to have two bins of drives or you
have to have the guy on the line set
the jumpers each time. Either of these will increase
manufacturing cost due to rework--with the jumpers he'll set
them incorrectly from time no matter how diligent he is, to
time, with the preconfigured drives they'll
get binned incorrectly from time to time. With the twisted
cable you only have to maintain one bin of identically
jumpered drives, eliminating that source of manufacturing
errors, at the cost of a slightly more expensive cable that
can be easily inspected.

Pity there have been bugger all PCs shipped with
more than one floppy drive for years and years
now, and even less with two identical floppy drives.

Nice theory. Pity about the reality tho.

The reality is that the twisted cable was use for both diskette
and hard drives

Duh.

and it was put into use in the era in which
dual diskette drives were the norm.

Nope.

Nope?

Nope.

I see.

You dont.

So would you be kind enough to provide the date on which
machines with dual diskette drives ceased to be commonplace
and the date on which IBM introduced the twisted diskette cable?

YOU made that claim. YOU get to provide the
substantiation for that claim. THATS how it works.

Fine, I remember personally repairing many machines
with dual diskette drives and twisted cables.

Separate issue entirely to 'the norm'

It does not have to be "the norm" for it to
result in savings in manufacturing cost.

I just commented on your 'the norm' there.

What "the norm"? I do not see the word "norm" in any statement that I have
made except those subsequent to your introduction of the term.

Its obvious that you should be able to do much better than that.

Why bother?

No if about that particular point given that the IBM PC which
was the only one that ever shipped with a significant number
of duplicated floppy drives didnt use a twisted floppy cable.

Even the XT didnt use a twisted floppy cable when made by IBM.

No, the XT used a set of links in a DIP frame, which links were cut as
required to get the right assignment.

Like I said, that was the result of a general cleanup of the detail
with the AT. Which hardly ever shipped with duplicate floppy drives.

And of course you have production figures for the AT listing how many were
shipped with one diskette drive vs two.

You'd better ask whoever it was that made that change.

It clearly cant have been for that manufacturing convenience
when the first of the PCs shipped by IBM with a twisted floppy
cable almost never was shipped with duplicated floppy drives.

Almost never? Can you put a number on "almost never"?

It happened to be one of the models that didnt use
a twisted floppy cable. And happened to be the only
model that was ever shipped in significant numbers
with duplicated floppy drives. Even the XT didnt.

Define "significant numbers".

Even you should be able to bullshit your way out of your
predicament better than that pathetic excuse for bullshit.
Bullshit.



Crap, that was what was seen right from the start with true clones.

What do "true clones" have to do with the matter at hand?

Corse it is.



Crap. The cabling was determined by the drive it was first used on.

And what drive was that?

And the use of a twisted control cable wasnt anything like universal
either.

So?

I'm going to have to let you believe that you have won this one.

 

[Jim Jones]

Jim Jones wrote:


Jim Jones wrote:


Jim Jones wrote:


Jim Jones wrote:


Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.misc Folkert Rienstra


[...]

If you're not sure about yours, do a Google search for
each drive's brand and model number and "jumper," to
see if yours are set correctly for the position you
want each in.

Pointless with a normal PC.

Nope, not with universal drives that can be jumpered to
respond to drive select A, B, C or D.

Actually I have one of these drives. Mightily old (720kB
3.5"). And I have seen a newer one as well somewhere. Not
all 3.5" floppies are designed for PC use only. The
Shuggart-bus definitely supports 4 floppies. I think the
design with the twisted cable was just to make it
idiot-proof. So no surprise Rod does not know about this
;-)

How odd that I've actually commented on it in the past and
even a pathetic excuse for a troll could find it in
groups.google.

Not so much "idiot proof" as easier to assemble. With
jumpers you either have to have two bins of drives or you
have to have the guy on the line set
the jumpers each time. Either of these will increase
manufacturing cost due to rework--with the jumpers he'll set
them incorrectly from time no matter how diligent he is, to
time, with the preconfigured drives they'll
get binned incorrectly from time to time. With the twisted
cable you only have to maintain one bin of identically
jumpered drives, eliminating that source of manufacturing
errors, at the cost of a slightly more expensive cable that
can be easily inspected.

Pity there have been bugger all PCs shipped with
more than one floppy drive for years and years
now, and even less with two identical floppy drives.

Nice theory. Pity about the reality tho.

The reality is that the twisted cable was use for both diskette
and hard drives

Duh.

and it was put into use in the era in which
dual diskette drives were the norm.

Nope.

Nope?

Nope.

I see.

You dont.

So would you be kind enough to provide the date on which
machines with dual diskette drives ceased to be commonplace
and the date on which IBM introduced the twisted diskette cable?

YOU made that claim. YOU get to provide the
substantiation for that claim. THATS how it works.

Fine, I remember personally repairing many machines
with dual diskette drives and twisted cables.

Separate issue entirely to 'the norm'

It does not have to be "the norm" for it to
result in savings in manufacturing cost.

I just commented on your 'the norm' there.

What "the norm"?

That one of yours about a screen up. Just above
the set of Nopes, with > >> >> >> >> in front of it.

I do not see the word "norm" in any statement that I have made
except those subsequent to your introduction of the term.

Best get your eyes test then.

Why bother?

Why indeed. You're doing such a pathetic job
of bullshitting your way out of your predicament
now that it would be a complete waste of time.

No, the XT used a set of links in a DIP frame, which
links were cut as required to get the right assignment.

No news.

And of course you have production figures for the AT listing
how many were shipped with one diskette drive vs two.

Dont need those, I know that few were
shipped with two identical floppy drives.

Almost never? Can you put a number on "almost never"?

Irrelevant. What matters is that it was a small minority
and wouldnt have been the reason for the change to
a twisted floppy cable when that wasnt used on the
original IBM PC which did ship with significantly more
systems with a pair of identical floppy drives installed.

Define "significant numbers".

Even you should be able to do better
than this pathetically hoary old ploy.

Doesnt need defining.

Bullshit.

Yep, thats what yours is in spades.

Clearly couldnt bullshit your way out of a wet paper bag
even if your pathetic excuse for a 'life' depended on that.

What do "true clones" have to do with the matter at hand?

The detail with the machines that werent true clones and only
attempted to be able to run the apps that would run on the
IBM PC is clearly irrelevant at that level of hardware detail.

And what drive was that?

You know what drive that was. So do I.

I'm going to have to let you believe that you have won this one.

Pathetic, really. Everyone can see for themselves
who got done like a ****ing dinner, yet again.

 

[Folkert Rienstra]

Jim Jones wrote:
"J. Clarke" (e-mail address removed)> wrote in message Arno Wagner wrote:
"Rod Speed" (e-mail address removed)> wrote in message
[...]


The reality is that the twisted cable was use for both diskette and hard
drives

It was?

Yep, with MFM, RLL and ESDI drives that were current at
the time that twisted cable approach showed up with floppys.

So, that is a NO then.

Wrong. Those are two different ways of achieving the
same effect, the drive ID being determined by the drive
connector used. Instead of having to fiddle with jumpers.


No news.

Apparently not, as it shows you wrong, again. Cable Select does NOT use a twist.

 

[Rod Speed]

Jim Jones wrote:
"J. Clarke" (e-mail address removed)> wrote in message Arno Wagner wrote:
"Rod Speed" (e-mail address removed)> wrote in message
[...]


The reality is that the twisted cable was use for both diskette and hard
drives

It was?

Yep, with MFM, RLL and ESDI drives that were current at
the time that twisted cable approach showed up with floppys.

So, that is a NO then.

Even you should be able to manage a more viable troll than that, child.

Apparently not, as it shows you wrong, again. Cable Select does NOT use a twist.

Never said it did, ****wit.

 

[chrisv]

I'm going to have to let you believe that you have won this one.

Like you have a choice? Ron^Hd will have the last word, no matter
what.