Re: PCI floppy controller

[Chuck Guzis via cctalk]

On 5/5/22 17:44, Charles Dickman wrote:
> On Thu, Apr 21, 2022 at 10:34 PM Chuck Guzis  > wrote:
> 
> On 4/21/22 18:01, Charles Dickman wrote:
> > On Thu, Apr 21, 2022 at 8:02 PM Chuck Guzis via cctal
> > I was at that point and looking at DP3T switches to have an external
> > connection as well. DP3T switches are mess.
> 
> You could also bring the floppy cable out to a standard DC-37 connector
> on a bracket, then use a ABCD switchbox to select whatever external
> DC-37-cabled floppy drive you wanted.
> 
> 
> Where would you see those DC37 connectors for external floppies? I
> remember them, but not exactly where. 
> 
> I ended up getting a DPDT switch from the hardware store. A bit of
> ribbon cable, some hot glue and a couple pop-rivets and it works like a

Back in the bad old days, DC37F was the common way to bring out external
floppies on the ISA and MC bus.   Consider, for example, the original
5150 and 5160 4-floppy controller--there's that DC37 on the bracket.

All of the standard IBM external PS/2 floppy boxes used DC37-terminated
cables.  e.g. IBM 4869 among others.

Similarly, third party controllers such as the Micro Solutions
CompatiCard line and others all used DC37 connectors on the bracket.

I even have brackets with a DC37 attached to a smaller PCB with the
usual 34-pin header.

For a motion-picture example, see https://youtu.be/ATUFjPldvcg

--Chuck

Re: PCI floppy controller

[Fred Cisin via cctalk]

On Thu, Apr 21, 2022 at 10:34 PM Chuck Guzis  wrote:

You could also bring the floppy cable out to a standard DC-37 connector
on a bracket, then use a ABCD switchbox to select whatever external
DC-37-cabled floppy drive you wanted.

On Thu, 5 May 2022, Charles Dickman via cctalk wrote:

Where would you see those DC37 connectors for external floppies? I remember
them, but not exactly where.

I ended up getting a DPDT switch from the hardware store. A bit of ribbon
cable, some hot glue and a couple pop-rivets and it works like a charm.


DC37 was used for the external floppy on PC/5150 and XT/5160
For the PS/2, IBM had  an adapter to bring that out.



DC37 was also used on the Canon CX-VDO laser printers.
My Cordata used DC37, and so did my JLASER and EiconScript (Postscript 
and PCL) interface card,  so I had ANOTHER DC37 A/B/C/D switch for my 
laser printer.

Re: PCI floppy controller

[Charles Dickman via cctalk]

On Thu, Apr 21, 2022 at 10:34 PM Chuck Guzis  wrote:

> On 4/21/22 18:01, Charles Dickman wrote:
> > On Thu, Apr 21, 2022 at 8:02 PM Chuck Guzis via cctal
> > I was at that point and looking at DP3T switches to have an external
> > connection as well. DP3T switches are mess.
>
> You could also bring the floppy cable out to a standard DC-37 connector
> on a bracket, then use a ABCD switchbox to select whatever external
> DC-37-cabled floppy drive you wanted.


Where would you see those DC37 connectors for external floppies? I remember
them, but not exactly where.

I ended up getting a DPDT switch from the hardware store. A bit of ribbon
cable, some hot glue and a couple pop-rivets and it works like a charm.


> --Chuck
>
>
-chuck

Re: PCI floppy controller

[Warner Losh via cctalk]

I'd gotten the impression that there was some angst in its community of
users
over something. I can't find now where I'd gotten that impression, though.
Mine
works great, and I've had no issues with it. They've been helpful when I've
reported
trouble I had using it, but it was pilot error on my part and they helped
me understand
what the reports and output of the tools were actually telling me.

Warner

On Sat, Apr 23, 2022 at 12:04 AM Tom Hunter  wrote:

> I am curious about your comment about "kryoflux going south".
> I did not hear about any problems. Could you please elaborate?
> I got mine about 2 or 3 years ago and it did everything I needed at the
> time, but haven't used it since.
>
> Thanks
> Tom
>
>
> On Sat, Apr 23, 2022 at 9:19 AM Warner Losh via cctalk <
> cctalk@classiccmp.org> wrote:
>
>> On Fri, Apr 22, 2022 at 7:07 PM Bill Gunshannon via cctalk <
>> cctalk@classiccmp.org> wrote:
>>
>> >
>> > As another person with a desire to be able to read/write/create
>> > disks of different sizes and formats I have found this interesting.
>> >
>> > So the question, then
>> >
>> > How hard would it be to make a floppy disk interface using an Arduino
>> > or even RasberryPi?  If you could do that the choices of interface
>> > to a PC opens up quite a bit.  It would never be like having a floppy
>> > hanging off the PC, but then none of the formats I am interested in
>> > are grounded in the PC anyway and utilities would need to be written
>> > to access them.
>> >
>> > comments?
>> >
>>
>> Isn't that what Greaseweasel  and similar do? I have a kyroflux that I use
>> to read floppies on my macbook. It can write as well and understands a ton
>> of formats. Greaseweasel is more available and supported (I got my
>> kyroflux
>> before things went south, so wouldn't recommend others get one these
>> days).
>>
>> Warner
>>
>

Re: PCI floppy controller

[Fred Cisin via cctalk]

On Sat, 23 Apr 2022, Bill Gunshannon via cctalk wrote:

Your right about all the available options.  Somewhere around here I
have a couple of P112 SBC's.  I wonder what the floppy controller in
that can do?  I am pretty sure it claimed compatibility with CP/M 8"
disks.  If so it can probably handle all various 5.25" formats as well.
Looks like I may have a number of things to play with while I spend
my summer stuck in the house.


Standard CP/M (8" SSSD)  was FM at 250K data transfer rate 
Most designers of such made an effort to keep it versatile.
Let's hope that they included MFM and data transfer rates of: 
125K (5.25" single density (TRS80 model I  and Early Osborne))

250K
500K (8" double density and 3.5"/5.25" 'High' density)

maybe even:
300K (5.25" 360K double density in a 360RPM 1.2M drive)
1000K (2.8M)

Re: PCI floppy controller

[Chuck Guzis via cctalk]

On 4/23/22 07:16, Liam Proven wrote:
> On Fri, 22 Apr 2022 at 23:41, Chuck Guzis  wrote:
>>
>> Take a look at the chip (DP8473) datasheet.   It boasts direct (no
>> buffer needed) support of up to 4 drives.   The rest is software; the
>> protocol is pretty much write some registers before/after
>> writing/reading to the buffer memory.  In other words, it's a low-level
>> interface protocol; there's really no intelligence in the unit.
> 
> TBH, I wouldn't know. I'm a software type at best. Interesting info, though!

An interesting aside is that on Adaptec and Future Domain SCSI ISA cards
with the NS chip, it's quite possible to run an additional wire between
the chip and the floppy header and get 3 floppies on a single cable.
DTC and Ultrastor used the "twisty twisty" cable on their cards to do
the same.   There also was a DTC (ESDI or SCSI, I don't recall) ISA card
that, with a jumper allowed one to run 4 floppies on single "flat"
ribbon cable.  Each drive had its own drive select (0,1,2,3) and all
drive motors ran at the same time, but it worked.

--Chuck

Re: PCI floppy controller

[Bill Gunshannon via cctalk]

On 4/22/22 21:48, Fred Cisin via cctalk wrote:

On Fri, 22 Apr 2022, Bill Gunshannon via cctalk wrote:

As another person with a desire to be able to read/write/create
disks of different sizes and formats I have found this interesting.
So the question, then
How hard would it be to make a floppy disk interface using an Arduino
or even RasberryPi?  If you could do that the choices of interface
to a PC opens up quite a bit.  It would never be like having a floppy
hanging off the PC, but then none of the formats I am interested in
are grounded in the PC anyway and utilities would need to be written
to access them.
comments?


There are a LOT of possibilities.

At one point, one of my associates was playing around with various "PC 
on a board" motherboards that were 5.25" floppy drive size. ("Quark" 
80186 equivalent of an Ampro Little Board)  He mounted it with spacers 
on a 5.25" drive, in an external case.  It was a complete PC, that 
looked like an externala drive.
His primary purpose was to build dedicated PC industrial data 
acquisition units.  (Elcompco made several data acquisition systems that 
interfaced directly with banks of elevators) With trivial some software 
on it, it could connect to a "real" PC and do disk I/O.



I once saw an extremely similar commercial product being marketed for 
Macintosh that was an "external 5.25" floppy drive that can read PC 
diskettes".  It was an Ampro Little Board on a drive, with software for 
letting the Macintosh access files on its disks.  They avoided 
mentioning what was inside the box, and presented it as a Macintosh 
special external drive.   (similar to the Macintosh version of Video 
Toaster having an Amiga in the box)
They added software to it to handle some CP/M formats.  I was amused 
that among the formats that they supported were a format where I had 
misspeled the format name (due to customer handwriting), and they copied 
my mispelling, and they had a format that I had put into XenoCopy for a 
friend to handle his on-off prototype machine that never went to market. 
(a non-deliberate Mountweazel poach flag copyright trap)



You could build a small box with a drive and either a from scratch 
controller, or a 765 (or better yet, a WD 179x), that connects to PC.
In that box, you could put almost anything that could work with the FDC 
and communicate.



But, as a first step, and "proof of concept" for an external box, why 
not just start with a 5160 or 5170, running software and communicating 
with your host PC?  Then, later, you could replace the 5160/5170 with a 
more compact dedicated bespoke device.



(OK, I'm still thinking in terms of the days when people were upgrading 
PCs and throwing out the old ones, so that an XT cost NOTHING)




Your right about all the available options.  Somewhere around here I
have a couple of P112 SBC's.  I wonder what the floppy controller in
that can do?  I am pretty sure it claimed compatibility with CP/M 8"
disks.  If so it can probably handle all various 5.25" formats as well.

Looks like I may have a number of things to play with while I spend
my summer stuck in the house.

bill

Re: PCI floppy controller

[Christian Corti via cctalk]

On Fri, 22 Apr 2022, "Maciej W. Rozycki" wrote:

You can of course build a PCI FDD interface around the NEC uPD765 or an
equivalent controller, but you can't make it compatible with existing PC
software, because too much PC specifics has been embedded there around the
8237 DMA controller and DMA page registers at fixed port I/O locations,
which is inherently incompatible with the PCI decoding model.


Yes, but I have never understood why you would need BIOS compatibility. 
Current operating systems have their own drivers. I mean, what would be 
the problem to write a, say, Linux driver for such a thing?
And you don't even need DMA for the FDC if you want to make it cheap. OTOH 
a small dedicated SRAM and supporting microcontroller on the PCI board 
would make up a great PCI floppy controller.



A feasible solution is a SCSI FDD option, such as the DEC RX23 device
(which is actually a whole embedded microcomputer built around an 8080 CPU
and using an 8237 DMA controller, an 8259 interrupt controller, a uPD765
floppy drive controller and a 5380 SCSI interface), which works as a
removable drive with any single-ended parallel SCSI host adapter, e.g.:


I have a DaynaFile II, it was once an external SCSI 5.25" FDD with 
proprietary protocol, designed for crappy Apple computers.
I had disassembled the firmware and documented the command set. And I 
think that I have redrawn the schematics at that time. It is much 
more capable of what the Apple driver might have supported.
The hardware itself is just a small board with a DP5380, 80C31, a 32kB 
SRAM and 2793 FDC.
So everyone shouting for a solution, I recommend looking for existing ones 
and eventually (re)build one from scratch. I mean, today you just need the 
FDC and a microcontroller with integrated USB or whatever to communicate 
with the host.


(Note: of course this applies only to standard IBM formats)

Christian

Re: PCI floppy controller

[Tom Hunter via cctalk]

I am curious about your comment about "kryoflux going south".
I did not hear about any problems. Could you please elaborate?
I got mine about 2 or 3 years ago and it did everything I needed at the
time, but haven't used it since.

Thanks
Tom


On Sat, Apr 23, 2022 at 9:19 AM Warner Losh via cctalk <
cctalk@classiccmp.org> wrote:

> On Fri, Apr 22, 2022 at 7:07 PM Bill Gunshannon via cctalk <
> cctalk@classiccmp.org> wrote:
>
> >
> > As another person with a desire to be able to read/write/create
> > disks of different sizes and formats I have found this interesting.
> >
> > So the question, then
> >
> > How hard would it be to make a floppy disk interface using an Arduino
> > or even RasberryPi?  If you could do that the choices of interface
> > to a PC opens up quite a bit.  It would never be like having a floppy
> > hanging off the PC, but then none of the formats I am interested in
> > are grounded in the PC anyway and utilities would need to be written
> > to access them.
> >
> > comments?
> >
>
> Isn't that what Greaseweasel  and similar do? I have a kyroflux that I use
> to read floppies on my macbook. It can write as well and understands a ton
> of formats. Greaseweasel is more available and supported (I got my kyroflux
> before things went south, so wouldn't recommend others get one these
> days).
>
> Warner
>

Re: PCI floppy controller

[Chuck Guzis via cctalk]

On 4/22/22 18:43, Bill Gunshannon via cctalk wrote:

> I guess I'll find out.  I just ordered one.  Shipping is almost as much
> as the device. :-(
> 
> Still think I will look into what it would take to access floppies
> from an Arduino.  They're fun to play with, too.

As far as I am aware, none of the "sampling"  (basically use an internal
timer to "capture" the interval between flux transitions) solutions have
BIOS Int 13 access nor Windows NT sector-level access.

If I'm wrong please feel free to correct me.

The principle is quite simple and is the same one used by the old
Catweasel board.   You have a free-running timer at some rate, say 24
Mhz.  Every time the magnetic flux on the floppy track reverses, you
grab the current counter value and store it away.   Some implementations
reset the counter at that point; others just let it run and correct the
counts at end-of-track.Then you go over the track data and derive
the content, using software to simulate a data separator.
For writing, you employ a similar counter idea, except the the counter
is programmed as a pulse width modulator fed by a stream of values. Very
simple--I can recall coaxing people into this on VCFed back around 2005
or so--I recall doing a very simple implementation employing a (now
long-EOLed) ATMega162 and an external SRAM.   It's not rocket science--a
$3 "Blue Pill" stm32f103 board MCU needs little other than a connector
to a floppy and some firmware.  It runs at 72MHz, which is more than
sufficient.  Data is streamed to the host via the integral USB connection.

However, it needs to be stated that everything from the Catweasel on
depends on post- or pre-processing.   As far as I know, none enjoys an
Int 13h interface, like a standard floppy controller would.

Now external drives like the Backpack did enjoy an Int 13h connection
because they use a standard FDC inside.   I suppose one could do the
same with a USB setup.   Mostly a matter of software.

--Chuck

Re: PCI floppy controller

[Fred Cisin via cctalk]

Isn't that what Greaseweasel  and similar do? I have a kyroflux that I use
to read floppies on my macbook. It can write as well and understands a ton
of formats. Greaseweasel is more available and supported (I got my 
kyroflux

before things went south, so wouldn't recommend others get one these
days).


On Fri, 22 Apr 2022, Bill Gunshannon via cctalk wrote:

I guess I'll find out.  I just ordered one.  Shipping is almost as much
as the device. :-(
Still think I will look into what it would take to access floppies
from an Arduino.  They're fun to play with, too.


In the early days of some of those devices, the primary users of them were 
interested in saving the raw track images for later recreation/copying of 
disks, and many didn't see any reason to want to even convert to sectors, 
much less parse the DIRectory and implement fucnctions of the file system 
to get FILES as output.



It would be interesting to hear about the current state of the art of 
software for them to use as sector readers and for which file systems 
there is now software to extract FILES.   (as opposed to raw image 
archiving for recreation/copying only)



--
Grumpy Ol' Fred ci...@xenosoft.com

Re: PCI floppy controller

[Fred Cisin via cctalk]

On Fri, 22 Apr 2022, Bill Gunshannon via cctalk wrote:

As another person with a desire to be able to read/write/create
disks of different sizes and formats I have found this interesting.
So the question, then
How hard would it be to make a floppy disk interface using an Arduino
or even RasberryPi?  If you could do that the choices of interface
to a PC opens up quite a bit.  It would never be like having a floppy
hanging off the PC, but then none of the formats I am interested in
are grounded in the PC anyway and utilities would need to be written
to access them.
comments?


There are a LOT of possibilities.

At one point, one of my associates was playing around with various "PC on 
a board" motherboards that were 5.25" floppy drive size. ("Quark" 80186 
equivalent of an Ampro Little Board)  He mounted it with spacers on a 
5.25" drive, in an external case.  It was a complete PC, that looked like 
an externala drive.
His primary purpose was to build dedicated PC industrial data acquisition 
units.  (Elcompco made several data acquisition systems that 
interfaced directly with banks of elevators) 
With trivial some software on it, it could connect to a "real" PC and do 
disk I/O.



I once saw an extremely similar commercial product being marketed for 
Macintosh that was an "external 5.25" floppy drive that can read PC 
diskettes".  It was an Ampro Little Board on a drive, with software for 
letting the Macintosh access files on its disks.  They avoided mentioning 
what was inside the box, and presented it as a Macintosh special external 
drive.   (similar to the Macintosh version of Video Toaster having an 
Amiga in the box)
They added software to it to handle some CP/M formats.  I was amused that 
among the formats that they supported were a format where I had misspeled 
the format name (due to customer handwriting), and they copied my 
mispelling, and they had a format that I had put into XenoCopy for a 
friend to handle his on-off prototype machine that never went to market. 
(a non-deliberate Mountweazel poach flag copyright trap)



You could build a small box with a drive and either a from scratch 
controller, or a 765 (or better yet, a WD 179x), that connects to PC.
In that box, you could put almost anything that could work with the FDC 
and communicate.



But, as a first step, and "proof of concept" for an external box, 
why not just start with a 5160 or 5170, running software and communicating 
with your host PC?  Then, later, you could replace the 5160/5170 with a 
more compact dedicated bespoke device.



(OK, I'm still thinking in terms of the days when people were upgrading 
PCs and throwing out the old ones, so that an XT cost NOTHING)


--
Grumpy Ol' Fred ci...@xenosoft.com

Re: PCI floppy controller

[Bill Gunshannon via cctalk]

On 4/22/22 21:19, Warner Losh wrote:



On Fri, Apr 22, 2022 at 7:07 PM Bill Gunshannon via cctalk 
mailto:cctalk@classiccmp.org>> wrote:



As another person with a desire to be able to read/write/create
disks of different sizes and formats I have found this interesting.

So the question, then

How hard would it be to make a floppy disk interface using an Arduino
or even RasberryPi?  If you could do that the choices of interface
to a PC opens up quite a bit.  It would never be like having a floppy
hanging off the PC, but then none of the formats I am interested in
are grounded in the PC anyway and utilities would need to be written
to access them.

comments?


Isn't that what Greaseweasel  and similar do? I have a kyroflux that I use
to read floppies on my macbook. It can write as well and understands a ton
of formats. Greaseweasel is more available and supported (I got my kyroflux
before things went south, so wouldn't recommend others get one these
days).

Warner


I guess I'll find out.  I just ordered one.  Shipping is almost as much
as the device. :-(

Still think I will look into what it would take to access floppies
from an Arduino.  They're fun to play with, too.

bill

bill

Re: PCI floppy controller

[Warner Losh via cctalk]

On Fri, Apr 22, 2022 at 7:07 PM Bill Gunshannon via cctalk <
cctalk@classiccmp.org> wrote:

>
> As another person with a desire to be able to read/write/create
> disks of different sizes and formats I have found this interesting.
>
> So the question, then
>
> How hard would it be to make a floppy disk interface using an Arduino
> or even RasberryPi?  If you could do that the choices of interface
> to a PC opens up quite a bit.  It would never be like having a floppy
> hanging off the PC, but then none of the formats I am interested in
> are grounded in the PC anyway and utilities would need to be written
> to access them.
>
> comments?
>

Isn't that what Greaseweasel  and similar do? I have a kyroflux that I use
to read floppies on my macbook. It can write as well and understands a ton
of formats. Greaseweasel is more available and supported (I got my kyroflux
before things went south, so wouldn't recommend others get one these
days).

Warner

Re: PCI floppy controller

[Bill Gunshannon via cctalk]

As another person with a desire to be able to read/write/create
disks of different sizes and formats I have found this interesting.

So the question, then

How hard would it be to make a floppy disk interface using an Arduino
or even RasberryPi?  If you could do that the choices of interface
to a PC opens up quite a bit.  It would never be like having a floppy
hanging off the PC, but then none of the formats I am interested in
are grounded in the PC anyway and utilities would need to be written
to access them.

comments?

bill

Re: PCI floppy controller

[Fred Cisin via cctalk]

On Fri, 22 Apr 2022, Maciej W. Rozycki via cctalk wrote:

You can of course build a PCI FDD interface around the NEC uPD765 or an
equivalent controller, but you can't make it compatible with existing PC
software, because too much PC specifics has been embedded there around the
8237 DMA controller and DMA page registers at fixed port I/O locations,
which is inherently incompatible with the PCI decoding model.


While the lack of DMA would make it impossible to have complete 
compatability, it could still be partially compatible and have its own 
version of INT13h that would work for most? floppy utility software.


Consider the PCJr.  It did not have DMA, and wasn't compatible with 
everything for many MORE reasons, but some/most INT13h access to floppies 
did work.
There were, however OTHER problems; IBM made the mistake of thinking that 
the PCJr could compete on its own as a home computer, failing to realize 
that everybody who used PCs at work expected to be able to use the PCJr as 
a PC, and to be able to expand it the same as a PC.  As a further example 
of IBM's error in perception of the PCJr, they supplied it with a chiclets 
keyboard (just like the Coco), and then later had to give away FREE "real" 
keyboard replacements for the chiclets (just like the Coco).



Don't expect access BELOW INT13h, talking to the DMA and FDC chips 
directly.   For example, reading side B of a Kaypro disk, where the head 
number field in the sector headers doesn't match the number of which 
head it is on, and isn't the expected '1'.   Fortunately, most computers 
with WD FDCs that used invalid head number fields in the sector headers 
didn't CARE what was there, and would work with disks formatted with 
correct head number fields.

Re: PCI floppy controller

[Chuck Guzis via cctalk]

On 4/22/22 15:47, Maciej W. Rozycki wrote:
> On Thu, 21 Apr 2022, Chuck Guzis via cctalk wrote:
> 
>> I suppose it might be possible to fashion a legacy floppy controller on
>> a PCI card with enough supporting logic to make it compatible with
>> existing software, but I'm not aware of such an effort.

>  A feasible solution is a SCSI FDD option, such as the DEC RX23 device
> (which is actually a whole embedded microcomputer built around an 8080 CPU 
> and using an 8237 DMA controller, an 8259 interrupt controller, a uPD765 
> floppy drive controller and a 5380 SCSI interface), which works as a 
> removable drive with any single-ended parallel SCSI host adapter, e.g.:

However--the SCSI floppy is treated as a normal relative-block device
(like a hard disk).  AFAIK, provisions aren't made for alternate
addressing schemes (e.g. first sector not being C0 H0 S1), FM encoding
or interesting formats, such XDF.

One might as well buy a cheap USB floppy drive.   It's a pretty safe bet
that you won't be able to read, much less format, an entire IBM System/3
floppy using one.

--Chuck

Re: PCI floppy controller

[Maciej W. Rozycki via cctalk]

On Thu, 21 Apr 2022, Chuck Guzis via cctalk wrote:

> I suppose it might be possible to fashion a legacy floppy controller on
> a PCI card with enough supporting logic to make it compatible with
> existing software, but I'm not aware of such an effort.

 You can of course build a PCI FDD interface around the NEC uPD765 or an
equivalent controller, but you can't make it compatible with existing PC 
software, because too much PC specifics has been embedded there around the 
8237 DMA controller and DMA page registers at fixed port I/O locations, 
which is inherently incompatible with the PCI decoding model.

 A feasible solution is a SCSI FDD option, such as the DEC RX23 device
(which is actually a whole embedded microcomputer built around an 8080 CPU 
and using an 8237 DMA controller, an 8259 interrupt controller, a uPD765 
floppy drive controller and a 5380 SCSI interface), which works as a 
removable drive with any single-ended parallel SCSI host adapter, e.g.:

scsi 2:0:4:0: Direct-Access DEC  RX23 (C) DEC 0054 PQ: 0 ANSI: 1 CCS

Such SCSI host adapters remain widely available as PCI and PCIe options.

 HTH,

  Maciej

Re: PCI floppy controller

[Grant Taylor via cctalk]

On 4/22/22 1:26 PM, Glen Slick via cctalk wrote:

Swearing about it doesn't make it so.


Agreed.

Though swearing about it does speak to how strongly I /thought/ it was 
the case.


Clearly I was wrong.  It's only been about two decades since I would 
have messed with this.  Maybe my grey matter is suffering bit rot faster 
than I realized.




--
Grant. . . .
unix || die

Re: PCI floppy controller

[Glen Slick via cctalk]

On Fri, Apr 22, 2022 at 11:25 AM Grant Taylor via cctalk
 wrote:
>
> I'd swear that I've used a PCI Adaptec card with a floppy controller.
> 2942 comes to mind.

Swearing about it doesn't make it so.

Are there any Adaptec SCSI controllers other than the various flavors
of  these models which have floppy controllers?

AHA-1522 (ISA)
AHA-1542 (ISA)
AHA-1742 (EISA)
AHA-2742 (EISA)
AHA-2842 (VLB)

Re: PCI floppy controller

[Warner Losh via cctalk]

On Fri, Apr 22, 2022, 12:25 PM Grant Taylor via cctalk <
cctalk@classiccmp.org> wrote:

> On 4/22/22 11:46 AM, Warner Losh via cctalk wrote:
> > By the time there were PCI Adaptec cards, there was no longer a floppy
> > controller on them that I ever saw. As others have pointed out,
> > though, it would need special drivers and/or BIOS support because
> > PCI devices mixed poorly with ISA DMA that the floppy was built on.
>
> I'd swear that I've used a PCI Adaptec card with a floppy controller.
> 2942 comes to mind.
>

I thought the 2942 had 2 SCSI channels, I thought. Google can't find a
definitive answer but all the 2940 cards on eBay didn't have obviously
unstuck parts for a floppy. The aha 1540 did...

Warner

-- 
> Grant. . . .
> unix || die
>

Re: PCI floppy controller

[Liam Proven via cctalk]

On Fri, 22 Apr 2022 at 19:11, Chuck Guzis via cctalk
 wrote:
>
> Back in the 90s, we bought these things by the carton, modified them to
> work with Japanese DOS 2.0 format (PC98) 3.5" floppies, rewrote the
> drivers, added a VxD for Win3.1 compatibility and sold a bunch of them.
>  Popular with some segments of the CNC and other crowds.

Huh! Nice work if you can get it.

> A not well-known fact is that the thing supports up to 4 drives and that
> the configuration NVRAM stores not only the "ID" of the unit but also
> the types of the 4 drives connected.

You mean, in principle 1 interface could control 4 drives? Wow!

> It's rare (and perhaps impossible) to find a real parallel port on a
> modern system--usb parallel dongles don't work

No, I wouldn't expect 'em to.

> and neither do the PCIe
> parallel port cards.

OK, now that surprised me. But on consideration, I suppose that they
appear at different locations.

0x378 for I/O and IRQ 7, wasn't it? :-)

0x3BC and 0x278 for LPT2 and LPT3.

I guess PCI[e] ones appear elsewhere and DOS doesn't know about the addresses.

A Linux driver might have a shot. Any Windows driver old enough to
drive a parallel port won't work on any currently-supported version of
Windows.

>   Along with the legacy floppy interface, the
> legacy serial and parallel ports may have been the last vestiges of the
> ISA architecture to be discarded.

Yup.

-- 
Liam Proven ~ Profile: https://about.me/liamproven
Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmail.com
Twitter/LinkedIn: lproven ~ Skype: liamproven
UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053

Re: PCI floppy controller

[Grant Taylor via cctalk]

On 4/22/22 11:46 AM, Warner Losh via cctalk wrote:
By the time there were PCI Adaptec cards, there was no longer a floppy 
controller on them that I ever saw. As others have pointed out, 
though, it would need special drivers and/or BIOS support because 
PCI devices mixed poorly with ISA DMA that the floppy was built on.


I'd swear that I've used a PCI Adaptec card with a floppy controller. 
2942 comes to mind.




--
Grant. . . .
unix || die

Re: PCI floppy controller

[Warner Losh via cctalk]

On Thu, Apr 21, 2022 at 7:54 PM Grant Taylor via cctalk <
cctalk@classiccmp.org> wrote:

> On 4/21/22 5:47 PM, Charles Dickman via cctalk wrote:
> > Were there ever any floppy controllers for the (parallel) PCI bus?
>
> Didn't some of the Adaptec SCSI cards have a floppy controller on them?
>
> Could that be made to work?
>

The AHA 15x2 cards had a floppy controller. It was a nothing special
floppy controller that you'd otherwise find bundled on a multi-function
card. These cards were ISA. The details of which controller varied over
time, IIRC, but I had one of these since I didn't have a multi-function
card in my 486 DX2-66 that I started my PC journey with (it took me
a while to give up on the Rainbow).

The AHA 1742 cards had a floppy controller on them as well. Same
deal: but this was a EISA card.

I'm told the AHA1642 was similar, but I've not seen a microchannel
version of the card.

By the time there were PCI Adaptec cards, there was no longer a
floppy controller on them that I ever saw. As others have pointed
out, though, it would need special drivers and/or BIOS support because
PCI devices mixed poorly with ISA DMA that the floppy was built on.

Warner

Re: PCI floppy controller

[Chuck Guzis via cctalk]

On 4/22/22 04:44, Liam Proven via cctalk wrote:

> The company did a range of parallel-port storage drives: CDs, tape
> drives and so on. Most were slow but worked, but the floppy drives
> were quite a good option at the time for things like laptops which
> couldn't accept another drive or controller, or for adding drives
> unsupported by the built-in controller. I used them for emergency
> backups, data transfer, data recovery and so on.

Back in the 90s, we bought these things by the carton, modified them to
work with Japanese DOS 2.0 format (PC98) 3.5" floppies, rewrote the
drivers, added a VxD for Win3.1 compatibility and sold a bunch of them.
 Popular with some segments of the CNC and other crowds.

If you check (very) old posts on VCFed, you may find the code I
published that provides a complete set of BIOS functions.  It
illustrates how the parallel link works, among other things.

Internals were pretty simple--a floppy drive (usually
Newtronics/Mitsumi), either an NSC 8374 FDC or later NSC 8477 FDC, an
8051-family MCU and about 16KB of SRAM and a small NVRAM chip to store
configuration information.

A not well-known fact is that the thing supports up to 4 drives and that
the configuration NVRAM stores not only the "ID" of the unit but also
the types of the 4 drives connected.

It's rare (and perhaps impossible) to find a real parallel port on a
modern system--usb parallel dongles don't work and neither do the PCIe
parallel port cards.   Along with the legacy floppy interface, the
legacy serial and parallel ports may have been the last vestiges of the
ISA architecture to be discarded.

--Chuck

Re: PCI floppy controller

[Liam Proven via cctalk]

On Fri, 22 Apr 2022 at 13:44, Liam Proven  wrote:

> 5¼":
> https://www.amazon.com/MICRO-SOLUTION-1-44MB-Backpack-Parallel/dp/B512MS

Oops, sorry, badly-chosen link. Both of those are, of course, 3½
drives. The company *did* also offer 5¼" units, though, as did
others...

https://www.vogons.org/viewtopic.php?t=72333

https://picclick.com/MicroSolutions-BackPack-525-Parallel-Port-Floppy-Drive-Rare-283066058252.html

Here's the manual:
http://minuszerodegrees.net/manuals/MicroSolutions/Micro%20Solutions%20-%20Backpack%20Diskette%20Drive%20-%20Users%20Guide%20-%201997.pdf

-- 
Liam Proven ~ Profile: https://about.me/liamproven
Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmail.com
Twitter/LinkedIn: lproven ~ Skype: liamproven
UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053

Re: PCI floppy controller

[Liam Proven via cctalk]

On Fri, 22 Apr 2022 at 01:48, Charles Dickman via cctalk
 wrote:
>
> Were there ever any floppy controllers for the (parallel) PCI bus?

Floppy *controllers*, no. Floppy *drives*, yes.

The Backpack range were the most well-known, I'd say.

e.g.

5¼":
https://www.amazon.com/MICRO-SOLUTION-1-44MB-Backpack-Parallel/dp/B512MS

3½":
https://www.ebay.com/itm/384823809302

The company did a range of parallel-port storage drives: CDs, tape
drives and so on. Most were slow but worked, but the floppy drives
were quite a good option at the time for things like laptops which
couldn't accept another drive or controller, or for adding drives
unsupported by the built-in controller. I used them for emergency
backups, data transfer, data recovery and so on.


-- 
Liam Proven ~ Profile: https://about.me/liamproven
Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmail.com
Twitter/LinkedIn: lproven ~ Skype: liamproven
UK: (+44) 7939-087884 ~ Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053

Re: PCI floppy controller

[Chuck Guzis via cctalk]

On 4/21/22 18:01, Charles Dickman wrote:
> On Thu, Apr 21, 2022 at 8:02 PM Chuck Guzis via cctalk


> I was at that point and looking at DP3T switches to have an external
> connection as well. DP3T switches are mess.

You could also bring the floppy cable out to a standard DC-37 connector
on a bracket, then use a ABCD switchbox to select whatever external
DC-37-cabled floppy drive you wanted.

They appear to still be offered in 2-way and 4-way varieties.

--Chuck

Re: PCI floppy controller

[Grant Taylor via cctalk]

On 4/21/22 5:47 PM, Charles Dickman via cctalk wrote:

Were there ever any floppy controllers for the (parallel) PCI bus?


Didn't some of the Adaptec SCSI cards have a floppy controller on them?

Could that be made to work?



--
Grant. . . .
unix || die

Re: PCI floppy controller

[Fred Cisin via cctalk]

On Thu, 21 Apr 2022, Charles Dickman via cctalk wrote:

Were there ever any floppy controllers for the (parallel) PCI bus? I
Googled a bunch and haven't found any.
I am trying to outfit a computer for the long haul that can run a bunch of
older software in virtual machines and do things like duplicate floppies in
different formats. The motherboard I have supports all the formats I have
tried, but only supports one drive. It also only has PCI and PCIe slots.


If you have floppy support already, couldn't you intercept the floppy 
cable and switch the drive selects?
OK, ideal would be software controlled switching, but even a physical 
toggle switch in the cable would let you change to another drive, 
including a DC37 connector for externals.



Didn't some of the Giga-Byte Technology GA series (GA-108) of PCI SCSI 
controllers have floppy support?

https://arvutimuuseum.ee/th99/c/E-H/20876.htm

Tyan S1363?
Tyan S1366?


'course FINDING one might not be possible

I've heard of a PCI to ISA bridge, but I've never seen one.  Did any such 
thing ever exist?Wouldn't something like that be necessary to get 
adequate compatability?

Re: PCI floppy controller

[Charles Dickman via cctalk]

On Thu, Apr 21, 2022 at 8:30 PM Mike Loewen via cctalk <
cctalk@classiccmp.org> wrote:

> On Thu, 21 Apr 2022, Charles Dickman via cctalk wrote:
> > I am trying to outfit a computer for the long haul that can run a bunch
> of
> > older software in virtual machines and do things like duplicate floppies
> in
> > different formats. The motherboard I have supports all the formats I have
> > tried, but only supports one drive. It also only has PCI and PCIe slots.
>
> You might consider going with a different (older) motherboard with a
> floppy
> controller that supports
>

I thought about that too, but I'm trying to stick with the hardware that I
have. It is an ASUS board and an AMD Phenom II X955 processor. I have found
a sweet spot between the Ubuntu version, kernel version and VMWARE version
that run my virtual machines.


> Mike Loewen mloe...@cpumagic.scol.pa.us
> Old Technology  http://q7.neurotica.com/Oldtech/


-chuck

Re: PCI floppy controller

[Charles Dickman via cctalk]

On Thu, Apr 21, 2022 at 8:02 PM Chuck Guzis via cctalk <
cctalk@classiccmp.org> wrote:

> On 4/21/22 16:47, Charles Dickman via cctalk wrote:
> > Were there ever any floppy controllers for the (parallel) PCI bus? I
> > Googled a bunch and haven't found any.
>


> external one.Works a treat--recall that you need only switch the
> drive select and motor enable lines, so a DPDT switch suffices.  I like
>

I was at that point and looking at DP3T switches to have an external
connection as well. DP3T switches are mess.


> --Chuck
>

-chuck

Re: PCI floppy controller

[Mike Loewen via cctalk]

On Thu, 21 Apr 2022, Charles Dickman via cctalk wrote:


Were there ever any floppy controllers for the (parallel) PCI bus? I
Googled a bunch and haven't found any.

I am trying to outfit a computer for the long haul that can run a bunch of
older software in virtual machines and do things like duplicate floppies in
different formats. The motherboard I have supports all the formats I have
tried, but only supports one drive. It also only has PCI and PCIe slots.


   You might consider going with a different (older) motherboard with a floppy 
controller that supports two drives and single-density (FM). I'm using an Abit 
KV8PRO with a 1.8GHz Athlon CPU, onboard 10/100/1000 ethernet, 1 AGP 8X/4X 
slot, 5 PCI slots, SATA and IDE drive support, and 4 USB ports. The floppy 
controller passes all of Dave Dunfield's TESTFDC tests except the 
double-density 128-byte sector tests. I haven't yet found a need for that 
format. I use this system to image and create 3-1/2", 5-1/4" and 8" diskettes, 
single and double-density.



Mike Loewen mloe...@cpumagic.scol.pa.us
Old Technology  http://q7.neurotica.com/Oldtech/

Re: PCI floppy controller

[Chuck Guzis via cctalk]

On 4/21/22 16:47, Charles Dickman via cctalk wrote:
> Were there ever any floppy controllers for the (parallel) PCI bus? I
> Googled a bunch and haven't found any.
> 
> I am trying to outfit a computer for the long haul that can run a bunch of
> older software in virtual machines and do things like duplicate floppies in
> different formats. The motherboard I have supports all the formats I have
> tried, but only supports one drive. It also only has PCI and PCIe slots.

None that I'm aware of--PC floppy driver software depends very heavily
on the ISA bus DMA and interrupt setup.  Even with no ISA slots, the
typical PC chipset provided the southbridge ISA hooks for a floppy
controller.   Gradually it has disappeared, along with the legacy serial
and parallel ports.

On one of my Socket 939 motherboards, I fashioned a bracket with a DC37F
connector and a switch, so I could switch the single floppy to an
external one.Works a treat--recall that you need only switch the
drive select and motor enable lines, so a DPDT switch suffices.  I like
the motherboard because it can handle MFM and FM encodings, as well as
the 128 byte MFM sectors.

I suppose it might be possible to fashion a legacy floppy controller on
a PCI card with enough supporting logic to make it compatible with
existing software, but I'm not aware of such an effort.

--Chuck

Re: PCI floppy controller

[Zane Healy via cctalk]

> On Apr 21, 2022, at 4:47 PM, Charles Dickman via cctalk 
>  wrote:
> 
> Were there ever any floppy controllers for the (parallel) PCI bus? I
> Googled a bunch and haven't found any.
> 
> I am trying to outfit a computer for the long haul that can run a bunch of
> older software in virtual machines and do things like duplicate floppies in
> different formats. The motherboard I have supports all the formats I have
> tried, but only supports one drive. It also only has PCI and PCIe slots.
> 
> -chuck

Catweasel?

http://wiki.icomp.de/wiki/Catweasel

Zane