15 May
2023
15 May
'23
8:16 p.m.
At the most recent CoCoFEST!, I brought home the old Glenside Club
Computer Hard Drive. The mechanism is an ST-251, and I was wondering if
someone on-list would be willing to attempt to pull data off the drive.
I have no ability to configure to read this drive type, and the data is
not precious or anything, I just though we should try to pull it off for
historical sake. I was not in the club when teh drive was in use, so I
do not know what could be on it. I assume BBS data, but it could be
anything.
Happy to post to someone who wants to give it a go. If the drive needs
to be destroyed to get the data, or if attempting to read the data
destroys the drive, I will not hold anyone responsible. I don't even
need the drive back, just data if it is recoverable.
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
16 May
16 May
1 p.m.
On Mon, May 15, 2023 at 11:21 PM Jim Brain via cctalk <cctalk(a)classiccmp.org>
wrote:
At the most recent CoCoFEST!, I brought home the old
Glenside Club
Computer Hard Drive. The mechanism is an ST-251, and I was wondering if
someone on-list would be willing to attempt to pull data off the drive.
In my experience, reading the data from this type of drive is dramatically
simplified if
you have the original controller it was attached to. If you can get your
hands on it, this
job will be many many times easier, and doable without special equipment.
-ken
1:16 p.m.
On 5/16/2023 3:00 PM, Kenneth Gober wrote:
On Mon, May 15, 2023 at 11:21 PM Jim Brain via cctalk
<cctalk(a)classiccmp.org> wrote:
At the most recent CoCoFEST!, I brought home the old Glenside Club
Computer Hard Drive. The mechanism is an ST-251, and I was
wondering if
someone on-list would be willing to attempt to pull data off the
drive.
In my experience, reading the data from this type of drive is
dramatically simplified if
you have the original controller it was attached to. If you can get
your hands on it, this
job will be many many times easier, and doable without special equipment.
-ken
I did not know that.
I do have the original controller, but it's a bit complicated.
The controller is a Burke & Burke CoCo HDD controller. I pulled the PCB
from it. Inside is 2 PCBs. One looks like a standard 8 bit ISA card
(WD1002A-WX1, no rev number), and the other is a small PCB that appears
to adapt the ISA bus to the CoCo bus (4 MSI TTL and a CR2032 battery).
I assume just having the ISA card would be enough...
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
1:54 p.m.
Just having the ISA card will probably not be enough unless you can find
an operating system that has drivers for that particular controller
hardware and disk format.
The color computer only had a few floppy formats (Coco, OS/9, Flex/StarDOS).
As for hard disk formats, I have no idea. I ran Flex and OS/9 on 6809
based computers with hard drives but what OS that controller was
designed for I have no idea.
Most of the CoCo floppy formats would probably not apply to even small
hard drives due to limitations of their file structures. For example
Flex only supported 256 tracks and 256 sectors/track with each sector
being 128 bytes (single density) or 256 bytes (double density). That's
a maximum size of 65536 sectors and 16,777,216 bytes. OS/9 could handle
larger drives but I don't remember the format they used.
The ST-251 has 820 Cylinders, 6 heads and 17 Sectors/Track. That's
83,640 sectors or 42,823,680 bytes (512 byte sectors).
Most likely there was some kind of driver for the CoCo that converted
the ST-251 into smaller logical drives for the CoCo Operating system.
In order to get the files off of the drive you will need to understand
the actual high level format of boot sectors, root directory and sub
directories as well as how the format ties sectors together into files.
I'm sorry but I am not familiar with any CoCo OS hard disk formats.
The STS-251 is a 50MB unformatted drive with
On 5/16/2023 3:16 PM, Jim Brain via cctalk wrote:
On 5/16/2023 3:00 PM, Kenneth Gober wrote:
On Mon, May 15, 2023 at 11:21 PM Jim Brain via
cctalk
<cctalk(a)classiccmp.org> wrote:
At the most recent CoCoFEST!, I brought home the old Glenside Club
Computer Hard Drive. The mechanism is an ST-251, and I was
wondering if
someone on-list would be willing to attempt to pull data off the
drive.
In my experience, reading the data from this type of drive is
dramatically simplified if
you have the original controller it was attached to. If you can get
your hands on it, this
job will be many many times easier, and doable without special
equipment.
-ken
I did not know that.
I do have the original controller, but it's a bit complicated.
The controller is a Burke & Burke CoCo HDD controller. I pulled the
PCB from it. Inside is 2 PCBs. One looks like a standard 8 bit ISA
card (WD1002A-WX1, no rev number), and the other is a small PCB that
appears to adapt the ISA bus to the CoCo bus (4 MSI TTL and a CR2032
battery). I assume just having the ISA card would be enough...
Jim
5:14 p.m.
On Tue, 16 May 2023, Mike Katz via cctalk wrote:
Most likely there was some kind of driver for the CoCo
that converted
the ST-251 into smaller logical drives for the CoCo Operating system.
One fellow, who used to be involved in Cocos, recalls one or more systems
that handled it by MANY "virtual floppies" on the drive.
I think that OS-9 may have had support for "big" drives.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
5:24 p.m.
The biggest drive I remember seeing on OS/9 was 20MB or 40MB. I don't
remember the File Allocation Table size or format.
On 5/16/2023 7:14 PM, Fred Cisin via cctalk wrote:
On Tue, 16 May 2023, Mike Katz via cctalk wrote:
Most likely there was some kind of driver for the
CoCo that converted
the ST-251 into smaller logical drives for the CoCo Operating system.
One fellow, who used to be involved in Cocos, recalls one or more
systems that handled it by MANY "virtual floppies" on the drive.
I think that OS-9 may have had support for "big" drives.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
5:30 p.m.
Well, that would be "spot on", as the formatted capacity of an ST-251 was
40 Megabytes.
When used with MS-DOS, prior to MS-DOS 3.31, it would be partitioned as
two 20MB, or as a 32MB plus an 8MB.
(V3.31 was the first version of MS-DOS to support a partition larger than
32MB)
On Tue, 16 May 2023, Mike Katz wrote:
> The biggest drive I remember seeing on OS/9 was 20MB or 40MB. I
> don't remember the File Allocation Table size or format.
>
> On 5/16/2023 7:14 PM, Fred Cisin via cctalk wrote:
>> On Tue, 16 May 2023, Mike Katz via cctalk wrote:
>>> Most likely there was some kind of driver for the CoCo that
>>> converted the ST-251 into smaller logical drives for the CoCo
>>> Operating system.
>>
>> One fellow, who used to be involved in Cocos, recalls one or more
>> systems that handled it by MANY "virtual floppies" on the drive.
>>
>> I think that OS-9 may have had support for "big" drives.
>>
>> --
>> Grumpy Ol' Fred cisin(a)xenosoft.com
6:36 p.m.
On Tue, May 16, 2023, 8:30 PM Fred Cisin via cctalk <cctalk(a)classiccmp.org>
wrote:
Well, that would be "spot on", as the
formatted capacity of an ST-251 was
40 Megabytes.
When used with MS-DOS, prior to
MS-DOS 3.31, it would be partitioned as
two 20MB, or as a 32MB plus an 8MB.
(V3.31 was the first version of MS-DOS to support a partition larger than
32MB)
That's how I used it on my DEC Rainbow under MS-DOS 2.11 and later 3.10b.
And recently under venix...
Warner
On Tue, 16 May 2023, Mike Katz wrote:
> The biggest drive I remember seeing on OS/9 was 20MB or 40MB. I
> don't remember the File Allocation Table size or format.
>
> On 5/16/2023 7:14 PM, Fred Cisin via cctalk wrote:
>> On Tue, 16 May 2023, Mike Katz via cctalk wrote:
>>> Most likely there was some kind of driver for the CoCo that
>>> converted the ST-251 into smaller logical drives for the CoCo
>>> Operating system.
>>
>> One fellow, who used to be involved in Cocos, recalls one or more
>> systems that handled it by MANY "virtual floppies" on the drive.
>>
>> I think that OS-9 may have had support for "big" drives.
>>
>> --
>> Grumpy Ol' Fred cisin(a)xenosoft.com
6:57 p.m.
>> The biggest drive I remember seeing on OS/9
was 20MB or 40MB. I
>> don't remember the File Allocation Table size or format.
> Well, that would be "spot on", as the formatted capacity of an ST-251 was
> 40 Megabytes.
When used with
MS-DOS, prior to
MS-DOS 3.31, it would be partitioned as
> two 20MB, or as a 32MB plus an 8MB.
> (V3.31 was the first version of MS-DOS to support a partition larger than
> 32MB) That's how I used it on my DEC Rainbow under
MS-DOS 2.11 and later 3.10b.
And recently under venix...
OEM versions of MS-DOS, particularly 2.11 and 3.31 often had changes made
by the OEM. Many minor ones, but also some major ones.
I should have worded that, "V3.31 was the first version of MS-DOS to
support a partition larger than 32MB, WITHOUT vendor/OEM modifications"
Disk formats other than the primary ones were often added by OEMs, such as
80 track, and 3.5" prior to 3.20. There were numerous implementations of
3.5" drives starting with V2.11, many of which were not directly
compatible with the mainstream ones that started with V3.20.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
8:35 p.m.
On 5/16/23 18:57, Fred Cisin via cctalk wrote:
On some controllers, DTC BXD06 BIOS for example, another DOS 2.x option
was available. One could split a 32MB drive into two 16MB drives, each
with a different BIOS (0x80 and 0x81) address.
In the days of 16 bit sector addresses, disks got larger than PCDOS's
ability to service them. One way around this was to incorporate a
software shim in the BIOS to block 512 byte physical sectors into larger
multiples (e.g. 1024, 4096, 8192...bytes). DOS could deal with this at
the expense of more memory consumed for buffers, but it worked, sort of.
Another option used was to address the disk via a network redirector,
which accessed files by name, not absolute sector.
All mostly forgotten today.
--Chuck
>> The
biggest drive I remember seeing on OS/9 was 20MB or 40MB. I
>> don't remember the File Allocation Table size or format.
> Well, that would be "spot on", as the formatted capacity of an ST-251
> was
> 40 Megabytes.
>> When used with MS-DOS, prior to
> MS-DOS 3.31, it would be partitioned as
>> two 20MB, or as a 32MB plus an 8MB.
>> (V3.31 was the first version of MS-DOS to support a partition larger
>> than
>> 32MB)
9:50 p.m.
On 5/16/2023 3:54 PM, Mike Katz wrote:
I'm sorry but I am not familiar with any CoCo OS
hard disk formats.
All valuable information, but I am not concerned about the FS format.
ONce the data can be retrieved from the platters, either I or others can
write some code or create a way to view the files. Mainly, I just need
help getting the digital data off the HDD.
Jim
4 p.m.
On Tue, 16 May 2023, Kenneth Gober via cctalk wrote:
On Mon, May 15, 2023 at 11:21 PM Jim Brain via cctalk
<cctalk(a)classiccmp.org>
wrote:
There's a gadget out there for imaging MFM drives - it uses a BeagleBone
as the core of it - I've got one, but I don't know how to use it well
enough for your task, but I'm sure someone else on this list has one.
(this thing: https://www.pdp8online.com/mfm/mfm.shtml)
g.
--
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.
http://www.diy-cockpits.org/coll - Go Collimated or Go Home.
Some people collect things for a hobby. Geeks collect hobbies.
ScarletDME - The red hot Data Management Environment
A Multi-Value database for the masses, not the classes.
http://scarlet.deltasoft.com - Get it _today_!
At the most recent CoCoFEST!, I brought home the
old Glenside Club
Computer Hard Drive. The mechanism is an ST-251, and I was wondering if
someone on-list would be willing to attempt to pull data off the drive.
In my experience, reading the data from this type of drive is dramatically
simplified if
you have the original controller it was attached to. If you can get your
hands on it, this
job will be many many times easier, and doable without special equipment.
2:05 p.m.
At the most recent CoCoFEST!, I brought home the old
Glenside Club
Computer Hard Drive. The mechanism is an ST-251, and I was wondering
if someone on-list would be willing to attempt to pull data off the
drive. I have no ability to configure to read this drive type, and
the data is not precious or anything, I just though we should try to
pull it off for historical sake.
The best way to approach this, given the interchange issues with MFM
disk controllers, is probably to use one of Dave Gesswein's MFM Emulator
devices. It'll give you a flux image that can then be decode.
There may not be a decoder for the CoCo format yet, but it's probably
not too far different from other common things, so hopefully it could be
constructed fairly easily. The MFMEmu community seems to be willing to
help with this.
De
3:06 p.m.
On Tue, May 16, 2023 at 4:05 PM Dennis Boone via cctalk
<cctalk(a)classiccmp.org> wrote:
> At the most recent CoCoFEST!, I brought home the
old Glenside Club
> Computer Hard Drive. The mechanism is an ST-251...
<
The best way to approach this, given the interchange
issues with MFM
disk controllers, is probably to use one of Dave Gesswein's MFM Emulator
devices. It'll give you a flux image that can then be decode.
I have an MDM Emulator and it's nice, on those occasions you are
trying to read a supported drive (it supports a _lot_ of encodings,
but not every single platform).
Two layers - fortunately in this case, the low-level format is known
(WD1002A-WX1) and that's good. I'd totally expect an MFM Emulator to
be able to pull bytes off the drive. I am not a CoCo person so I have
no idea what tools can be used to pull files from a raw pile of disk
blocks there.
-ethan
3:30 p.m.
Tony in response to your original idea of wanting to download images for use on you
existing machines ( did i get that right?), i think you have everything you need already.
Download the images to your win 8 box then use file transfer software (kermit or xmodem)
to serially transfer to the specific box you want to use the software on and the use the
floppy on that box to write the floppies. It seems like there is a version of kermit made
for every box imaginable. The only possible gotcha is does the box have a serial port.
Sent from my iPhone
On May 16, 2023, at 15:06, Ethan Dicks via cctalk
<cctalk(a)classiccmp.org> wrote:
On Tue, May 16, 2023 at 4:05 PM Dennis Boone via cctalk
<cctalk(a)classiccmp.org> wrote:
> At the most recent CoCoFEST!, I brought home
the old Glenside Club
> Computer Hard Drive. The mechanism is an ST-251...
<
The best way to approach this, given the
interchange issues with MFM
disk controllers, is probably to use one of Dave Gesswein's MFM Emulator
devices. It'll give you a flux image that can then be decode.
I have an MDM Emulator and it's nice, on those occasions you are
trying to read a supported drive (it supports a _lot_ of encodings,
but not every single platform).
Two layers - fortunately in this case, the low-level format is known
(WD1002A-WX1) and that's good. I'd totally expect an MFM Emulator to
be able to pull bytes off the drive. I am not a CoCo person so I have
no idea what tools can be used to pull files from a raw pile of disk
blocks there.
-ethan
3:42 p.m.
On Tue, 16 May 2023, Wayne S via cctalk wrote:
Tony in response to your original idea of wanting to
download images for
use on you existing machines ( did i get that right?), i think you have
everything you need already. Download the images to your win 8 box then
use file transfer software (kermit or xmodem) to serially transfer to
the specific box you want to use the software on and the use the floppy
on that box to write the floppies. It seems like there is a version of
kermit made for every box imaginable. The only possible gotcha is does
the box have a serial port.
He would have to add a serial port (USB to serial dongle).
Although, . . .
many years ago, in the early days of USB, there was a cable and software
provision for transferring files USB yo USB. 'course, it's doubtful that
any of his other machines have USB.
Similarly, he could buy a cheap external USB 3.5" drive. Write content to
that drive on the modern machine, and read those floppies on the older
machines. The readily avaailable one have firmware that only supports
720K, 1.4M, and [sometimes] NEC-style "mode 3".
There do not seem to be any currently available USB external drives that
support cnaything other than a 3.5" drive integrated with the controller.
There ONCE was one with a non-integrated controller that could be modified
for 3", 3.25', 5.25" or 8"
I get the implication that he is considering USB flux-transition devices
that could be coerced into acting as a general purpose floppy controller.
3:55 p.m.
Fred, glad you chimed in.
If you have the original post, Tony wants to download different things images for those
machines, probably from the internet and use the software on those machines via floppy.
As another item, he acquired a coco computer hard disk that he like to get the data from.
A greezweasel was suggested.
So he has 2 somewhat related tasks.
Sent from my iPhone
On May 16, 2023, at 15:42, Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
On Tue, 16 May 2023, Wayne S via cctalk wrote:
Tony in response to your original idea of wanting
to download images for use on you existing machines ( did i get that right?), i think you
have everything you need already. Download the images to your win 8 box then use file
transfer software (kermit or xmodem) to serially transfer to the specific box you want to
use the software on and the use the floppy on that box to write the floppies. It seems
like there is a version of kermit made for every box imaginable. The only possible gotcha
is does the box have a serial port.
He would have to add a serial port (USB to serial dongle).
Although, . . .
many years ago, in the early days of USB, there was a cable and software provision for
transferring files USB yo USB. 'course, it's doubtful that any of his other
machines have USB.
Similarly, he could buy a cheap external USB 3.5" drive. Write content to that
drive on the modern machine, and read those floppies on the older machines. The readily
avaailable one have firmware that only supports 720K, 1.4M, and [sometimes] NEC-style
"mode 3".
There do not seem to be any currently available USB external drives that support
cnaything other than a 3.5" drive integrated with the controller. There ONCE was one
with a non-integrated controller that could be modified for 3", 3.25', 5.25"
or 8"
I get the implication that he is considering USB flux-transition devices that could be
coerced into acting as a general purpose floppy controller.
4:04 p.m.
On Tue, 16 May 2023, Wayne S wrote:
Fred, glad you chimed in.
If you have the original post, Tony wants to download different things images for those
machines, probably from the internet and use the software on those machines via floppy.
As another item, he acquired a coco computer hard disk that he like to get the data from.
A greezweasel was suggested.
So he has 2 somewhat related tasks.
Actually, the Coco harddisk was Jim Brain.
So, we have unwittingly conflated two threads.
I'm sure that Tony would like to add full function floppy capability to
his modern machine. That may be more difficult, but simply writing 3.5"
disk, with no other capabilities is trivial and cheap. For full function,
he needs to put together a more elaborate device.
For Jim Brain's Coco disk, my inclination would be to image it on an ISA
machine using the WD controller. but, an argument was made that a flux
transition read might be a way to cut down on the number of reads.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
4:36 p.m.
On 5/16/23 16:04, Fred Cisin via cctalk wrote:
For Jim Brain's Coco disk, my inclination would be to image it on an ISA
machine using the WD controller. but, an argument was made that a flux
transition read might be a way to cut down on the number of reads.
Bear in mind that the datarate of a ST506 MFM hard drive is 5MHz, as
opposed to 500KHz for an 8" MFM floppy, so the sample clock may have to
run quite a bit faster--should not be a problem on any modern MCU.
But also note that the data lines to the drive are *differential* not
single-ended, so you'll also need RS422 receivers as well as proper
termination.
FWIW,
Chuck
8:56 p.m.
On Tue, May 16, 2023 at 11:42 PM Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
That was the first thing I bought for this machine. And Kermit was one
of the first things I installed. Last time I used it was yesterday to
transfer an EPROM dump file from my HP95LX...
But I really would like to get a more direct solution.
As for the target machine having a serial port, one of the machines I
want to get stuff onto is an Osborne 1A. The serial port on that is
horrible. The baud rate generator divides down the master clock to get
19200Hz. That's fed to the serial chip which, amazingly for a Z80
machine, is a 6850. You can program that to divide by 16 (for 1200
baud) or divide by 64 (for 300 baud). That's it. OK, there's a jumper
on the mainboard to double those rates, and a cut-n-wire modification
in the technical manual for 9600 and 2400 baud, but....
On Tue, 16 May 2023, Wayne S via cctalk wrote:
> Tony in response to your original idea of wanting to download images for
> use on you existing machines ( did i get that right?), i think you have
Yes. I've got the machines running, I see software for them on
websites (including bitsavers), I want to use it.
everything you
need already. Download the images to your win 8 box then
use file transfer software (kermit or xmodem) to serially transfer to
the specific box you want to use the software on and the use the floppy
on that box to write the floppies. It seems like there is a version of
kermit made for every box imaginable. The only possible gotcha is does
the box have a serial port.
He would have to add a serial port (USB to serial dongle).
Although, . . .
many years ago, in the early days of USB, there was a cable and software
provision for transferring files USB yo USB. 'course, it's doubtful that
any of his other machines have USB.
If my other machines had USB I'd just put the files on a memory stick.
Similarly, he could buy a cheap external USB 3.5" drive. Write content to
that drive on the modern machine, and read those floppies on the older
machines. The readily avaailable one have firmware that only supports
720K, 1.4M, and [sometimes] NEC-style "mode 3".
I have one but AFAIK it only supports 1.4M. A format that few of my
other machines support.
I get the implication that he is considering USB
flux-transition devices
that could be coerced into acting as a general purpose floppy controller.
EXACTLY! I was told that was the best solution for this sort of thing.
Are there any downsides to doing it that way?
If I do go that route, what are the options? I have no knowledge of
them and thus no preference for one over another
As I said at the start I am clueless about this. I really need
somebody to talk me through it, what to get, what to build, what to
download etc.
-tony
9:29 p.m.
> Similarly, he could buy a cheap external USB
3.5" drive. Write content to
> that drive on the modern machine, and read those floppies on the older
> machines. The readily avaailable one have firmware that only supports
> 720K, 1.4M, and [sometimes] NEC-style "mode 3".
On Wed, 17 May 2023, Tony Duell wrote:
I have one but AFAIK it only supports 1.4M. A format
that few of my
other machines support.
Have they stopped making ones that include 720K?
That's something that almost all of your MFM machines could be coerced
into handling.
> I get the implication that he is considering USB
flux-transition devices
> that could be coerced into acting as a general purpose floppy controller.
I am not adequately familiar with them.
Last time that I tried to research it, I found that there had once been an
external drive in which the USB and controller werenot integrated with the
drive electronics, so that it could easily get a different drive
connected. It is, of course, not available anywhere.
I also saw a datasheet for a chip that was a USB floppy controller! It
also does not seem to be available.
But, that seems to now be the direction that flux transition devices are
heading!
EXACTLY! I was told that was the best solution for
this sort of thing.
Are there any downsides to doing it that way?
If I do go that route, what are the options? I have no knowledge of
them and thus no preference for one over another
As I said at the start I am clueless about this. I really need
somebody to talk me through it, what to get, what to build, what to
download etc.
In the earlier days of the flux transition devices, I found it frustrating
that many people talking about them would list "formats that it can
handle", but fail to differentiate, and maybe not even know, the
difference between creating an image that could be used for re-creating a
copy, VS producing a collection of sectors, VS understanding the file
systems to be able to extract files. As you know, my work in the 1980s
and 1990s was in parsing alien file systems, and transferring files with
simple INT13h sector reading.
From what I've heard, there has been substantial progress on the flux
transition devices, with decoding the track to sectors, and even support
of some file systems!
--
Grumpy Ol' Fred cisin(a)xenosoft.com
9:54 p.m.
On 5/16/23 21:29, Fred Cisin via cctalk wrote:
For years I have been telling the community that flux transition is
easy-peasy on modern MCUs. You have fast timers, "capture mode" and
even DMA for the capture process.
After that, it's mostly a matter of knowing the modulation method and ID
address and data marker encoding.
I routinely use (my own code) the method for getting at the guts of
RX01/RX02 disks as well the oddball ones, such as Wang 2200 hard sector.
My Pertec-interface tape controller is much the same--wiggle the right
lines and stash the data on the internal SD card.
It's not hard!
--Chuck
From what
I've heard, there has been substantial progress on the flux
transition
devices, with decoding the track to sectors, and even support
of some file systems!
17 May
17 May
7:59 a.m.
On Wed, May 17, 2023 at 5:54 AM Chuck Guzis via cctalk
<cctalk(a)classiccmp.org> wrote:
On 5/16/23 21:29, Fred Cisin via cctalk wrote:
For years I have been telling the community that flux transition is
easy-peasy on modern MCUs. You have fast timers, "capture mode" and
even DMA for the capture process.
[..]
From what
I've heard, there has been substantial progress on the flux
transition devices,
with decoding the track to sectors, and even support
of some file systems!
It's not hard!
It's not hard if you know about modern microcontrollers, know how to
program them, know how to handle the USB interface back to the modern
machine, know how to write programs on said modern machine to talk to
the microcontroller over the USB interface and so on.
I know NONE of that.
It's not hard to rebuild a floppy drive and align it from scratch.
It's not hard to understand the microcode in an HP9830 and its HP11305
disk control. It's not hard to replace heads in an RK05. It's not hard
to wire up a processor from a pile of TTL chps. It's not hard to make
an interface between a Trend HSR500P tape reader and a TRS-80 CoCo.
It's not hard to rebullt a rotary telephone dial. it's not hard to
repair a spring-driven chiming/striking clock. It's not hard to...
I've done them all over the years. This does not mean I can design and
build a flux-transition type of floppy disk reader/writer. Actually I
probaably could if I had to but I understand such devices already
exist so I'd rather use a known design if there is a recomended one,
one that people have experience of.
-tony
7:48 a.m.
On Wed, May 17, 2023 at 5:29 AM Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
I've never found one that claims to support 720K.
OK, OK... When I have a little (?) spare time I'll pull my USB floppy
drive to bits and try to work out just what the hardware consists of.
> Similarly, he could buy a cheap external USB
3.5" drive. Write content to
> that drive on the modern machine, and read those floppies on the older
> machines. The readily avaailable one have firmware that only supports
> 720K, 1.4M, and [sometimes] NEC-style "mode 3".
On Wed, 17 May 2023, Tony Duell wrote:
I have one but AFAIK it only supports 1.4M. A
format that few of my
other machines support.
Have they stopped making ones that include 720K? That's something that almost all of your MFM
machines could be coerced
into handling.
Nor am I,which is why I am asking about them.
I've heard they are a possible solution to my problems. I would like
to know more, which ones exist, which are recomended (the
Greaseweazel, the only one that has been seriously suggested to me, is
at least open source and has schematics available), what they will do,
etc
And to jump to a later point you make, I want to know just what
software tools exist to deal with the flux-transition file (if that's
the term). For example for an FM or MFM disk image, are there tools to
convert between a .IMD file and said flux transition file, between a
.TD0 file and said flux transition file, etc.
And what software tools exist to work on disk images. If I have a .IMD
file of a CP/M disk, say, can I add a file to it, for example?
-tony
> I get the implication that he is considering
USB flux-transition devices
> that could be coerced into acting as a general purpose floppy controller.
I am not adequately familiar with them. 
9:53 a.m.
On Wed, 17 May 2023 at 05:29, Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
Have they stopped making ones that include 720K?
I have 2 USB floppy drives and have successfully read 720 kB disks
with them, and also MacOS 1.4 MB disks.
I think they should also write 720 kB disks.
What they won't handle are DD formats that don't use the standardPC
disk controller: Amiga disk, DD Mac disks, etc.
--
Liam Proven ~ Profile: https://about.me/liamproven
Email: lproven(a)cix.co.uk ~ gMail/gTalk/FB: lproven(a)gmail.com
Twitter/LinkedIn: lproven ~ Skype: liamproven
IoM: (+44) 7624 277612: UK: (+44) 7939-087884
Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053
10:02 a.m.
That is because Amiga uses GCR recording rather then FM or MFM.
On 5/17/2023 11:53 AM, Liam Proven via cctalk wrote:
On Wed, 17 May 2023 at 05:29, Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
Have they stopped making ones that include 720K?
I have 2 USB floppy drives and have successfully read 720 kB disks
with them, and also MacOS 1.4 MB disks.
I think they should also write 720 kB disks.
What they won't handle are DD formats that don't use the standardPC
disk controller: Amiga disk, DD Mac disks, etc.
12:22 p.m.
> What they won't handle are DD formats that
don't use the standardPC
> disk controller: Amiga disk, DD Mac disks, etc.
The few external USB drives that I have tried can't even handle most of
the stuff that a standard PCdisk controller can. Their firmware is locked
in to a few specific formats, with no way to access a different file
system, change sector size, etc.
If you know of an external USB drive that does have the cpabilities of a
standard PC disk controller, please tell us what you can of make, model,
supplier, availability, etc.
On Wed, 17 May 2023, Mike Katz via cctalk wrote:
That is because Amiga uses GCR recording rather then
FM or MFM.
Apple2, Commodore 64, Mac 400K/800K, and many others are GCR.
For the Mac 1.4M format, Apple switched to MFM, and it is similar to PC
1.4M, but with a different directory/file system.
Amiga, however is NOT GCR! It is MFM, but without the IBM/WD track and
sector layout. The NEC 765 is designed for MFM with the IBM/WD track and
sector layout, so it is not designed for such a format. There are tricks
to do it, anyway, by changing drive select in mid-read, etc. Far better
to do it with a flux transition device.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
12:49 p.m.
On 5/17/23 12:22, Fred Cisin via cctalk wrote:
If you know of an external USB drive that does have
the cpabilities of a
standard PC disk controller, please tell us what you can of make, model,
supplier, availability, etc.
Interestingly, the Micro Solutions Backpack floppy drives do have all
the capabilities of a standard PC controller; they're basically and FDC,
an 8051 MCU and some added SRAM. You can fire off FDC commands over a
parallel interface (I know, "what's that?")
For commercial applications, the USB Mass Storage Device standard is
patterned after SCSI; as a matter of fact, it uses SCSI CDBs embedded in
a USB packet to work. As users of SCSI floppy drives know, that's just
a subset of the stuff that can be done with a legacy FDC setup.
That isn't to say that someone hasn't rolled a one-off project for
this--I know of at least one. It requires its own Windows drivers.
As much as Tony doesn't like it, I need to point out that a modern MCU
quite often has as much (or more) RAM, and runs faster than many older
PCs. Consider, for example, the lowly STM32H7A3 series. 1.4MB of RAM,
2MB of program flash, 5 DMA controllers, ethernet, TFT LCD, up to 164 5V
tolerant GPIOs, USB OTG...I won't go on.
Why tinker around with a PC when your MCU is more powerful? I store my
retrieved data on a 32GB SD card.
Yeah, I know, this is a "classic" list and I shouldn't discuss anything
much past an 80386.
--Chuck
1:06 p.m.
I have to agree with the folk on here who recommend some kind of flux
reader/writer like the greaseweazle.
It handles any format, handles most any data rate and has more ram/rom
and cpu horsepower than an old PC. And is the size of a deck of cards.
I have mine stored inside a dual 8" drive cabinet.
Though I am only using single sided drives (for reading RX01/RX02
drives). I know it can handle double sided drives.
And all of the source is open source so you can modify it for any format
you want.
On 5/17/2023 2:49 PM, Chuck Guzis via cctalk wrote:
On 5/17/23 12:22, Fred Cisin via cctalk wrote:
If you know of an external USB drive that does
have the cpabilities of a
standard PC disk controller, please tell us what you can of make, model,
supplier, availability, etc.
Interestingly, the Micro Solutions Backpack floppy
drives do have all
the capabilities of a standard PC controller; they're basically and FDC,
an 8051 MCU and some added SRAM. You can fire off FDC commands over a
parallel interface (I know, "what's that?")
For commercial applications, the USB Mass Storage Device standard is
patterned after SCSI; as a matter of fact, it uses SCSI CDBs embedded in
a USB packet to work. As users of SCSI floppy drives know, that's just
a subset of the stuff that can be done with a legacy FDC setup.
That isn't to say that someone hasn't rolled a one-off project for
this--I know of at least one. It requires its own Windows drivers.
As much as Tony doesn't like it, I need to point out that a modern MCU
quite often has as much (or more) RAM, and runs faster than many older
PCs. Consider, for example, the lowly STM32H7A3 series. 1.4MB of RAM,
2MB of program flash, 5 DMA controllers, ethernet, TFT LCD, up to 164 5V
tolerant GPIOs, USB OTG...I won't go on.
Why tinker around with a PC when your MCU is more powerful? I store my
retrieved data on a 32GB SD card.
Yeah, I know, this is a "classic" list and I shouldn't discuss anything
much past an 80386.
--Chuck
9:16 p.m.
On Wed, May 17, 2023 at 9:28 PM Mike Katz via cctalk
<cctalk(a)classiccmp.org> wrote:
I have to agree with the folk on here who recommend some kind of flux
reader/writer like the greaseweazle.
OK, that's what I thought.
Now what are the options. Greaseweazle or.... ? What are the
advantages and disadvantates of each?
For the Greaseweazle it looks like I can get one and it seems to be
open source with schematics of the hardware. I'd prefer more buffering
of the disk drive signals, but anyway. Will it do what I want?
-tony
18 May
18 May
5:47 a.m.
Re. other flux options, there's also the KryoFlux floppy controller, or if you're
an Apple user the applesauce floppy controller.
The Greaseweazle is an open source solution, and likely the most cost effective.
On Thursday, May 18, 2023 at 12:16:42 AM EDT, Tony Duell via cctalk
<cctalk(a)classiccmp.org> wrote:
On Wed, May 17, 2023 at 9:28 PM Mike Katz via cctalk
<cctalk(a)classiccmp.org> wrote:
I have to agree with the folk on here who recommend some kind of flux
reader/writer like the greaseweazle.
OK, that's what I thought.
Now what are the options. Greaseweazle or.... ? What are the
advantages and disadvantates of each?
For the Greaseweazle it looks like I can get one and it seems to be
open source with schematics of the hardware. I'd prefer more buffering
of the disk drive signals, but anyway. Will it do what I want?
-tony
7:15 a.m.
On 18/05/2023 05:16, Tony Duell via cctalk wrote:
Now what are the options. Greaseweazle or.... ? What
are the
advantages and disadvantates of each?
For the Greaseweazle it looks like I can get one and it seems to be
open source with schematics of the hardware. I'd prefer more buffering
of the disk drive signals, but anyway. Will it do what I want?
Both Greaseweazle and FluxEngine are open source software and based on
(different) standard hardware.
A ready built Greaseweazle is less than £25 and the PSoC? dev board the
FluxEngine uses was about £20 but you get to solder on a connector.
I picked the FluxEngine because I could get hold of the parts at the
time, and I still think that's probably your main consideration.
Software wise they seem to have similar capabilities.
If you have a specific list of formats you care about you could check:
Geaseweazel formats:
https://github.com/keirf/greaseweazle/wiki/Supported-Image-Types
FluxEngine formats: http://cowlark.com/fluxengine/index.html
There are other flux readers out there but they either don't seem to
have much momentum behind them (so you might be stuck if you need a new
format added) or they're closed like KyroFlux.
At ~£25 you're unlikely to lose much with either of the two front
runners :-)
Antonio
--
Antonio Carlini
antonio(a)acarlini.com
8:17 a.m.
On 2023-05-18 8:15 a.m., Antonio Carlini via cctalk wrote:
There are other flux readers out there but they either don't seem to
have much momentum behind them (so you might be stuck if you need a new
format added) or they're closed like KyroFlux.
At ~£25 you're unlikely to lose much with either of the two front
runners :-)
But what if I want RS232 serial interface instead of USB?
Antonio
Ben.
8:48 a.m.
On Thu, May 18, 2023 at 3:16 PM Antonio Carlini via cctalk
<cctalk(a)classiccmp.org> wrote:
At ~£25 you're unlikely to lose much with either
of the two front
runners :-)
Unfortunately in my case that is not true.
I ordered a Greaseweazle earlier today and downloaded the software. Of
course there is no such thing as documentation....
I read on the web site that to use it under Windows 8.1 I had to
install a device driver and to do that I needed a program called
'zadig.exe'. I downloaded that following the link on the Greaseweazle
page.
Now I don't yet have the Greaseweazle but I decided to just check that
the programs would run. They do not
The gw software itself falls over with a moan about a missing .dll.
The bit I recognise is 'stdio'. No idea where or how to get htat.
zadig was worse. I gave it permission to make changes but AFAIK didn't
ask it to change anything. None-the-less I've lost RS232
communications (the USB-serial cable was plugged in at the time). I
can find no way to get that to work again.
So I've lost the ability to program and read PALs and EPROMs. talk to
my palmtops, calcultors and other machines and so on. Bascially I
can't do much..
I wish I'd never listened to people who said this was easy and would work fine.
Never again.
-tony
9:05 a.m.
On 5/18/23 08:48, Tony Duell via cctalk wrote:
I wish I'd never listened to people who said this
was easy and would work fine.
Never again.
I warned you about modern open-source, didn't I?
I'm surprised that nobody suggested the Catweasel line. Probably one of
the first, if not the first, transition recorder generally available.
Ranges from the Mark I, which is an ISA device to the Mark 4, which is
PCI. Long out of production--I suspect that Jens decided that he had to
move on.
Software for that was always open-source, yet nobody seems to remember it.
I suspect that greasweazle appeals because it's cheap. There's also
Kyroflux, DeviceSide, FluxEngine...using MCU based designs.
The idea's the same. What I'm a bit surprised about is that there has
been no emulation of a generic floppy controller offered. It can't be
that complex; if I recall correctly the NEC 765 only used 1100 words of
microcode.
--Chuck
9:27 a.m.
On Thu, May 18, 2023 at 5:05 PM Chuck Guzis via cctalk
<cctalk(a)classiccmp.org> wrote:
On 5/18/23 08:48, Tony Duell via cctalk wrote:
Indeed you did. I should have listened to you.
I wish I'd never listened to people who said
this was easy and would work fine.
Never again.
I warned you about modern open-source, didn't I? I'm surprised that nobody suggested the Catweasel
line. Probably one of
the first, if not the first, transition recorder generally available.
Ranges from the Mark I, which is an ISA device to the Mark 4, which is
PCI. Long out of production--I suspect that Jens decided that he had to
move on.
Problem is that I have no ISA machines with a USB port. And nothing at
all with PCI slots.
Software for that was always open-source, yet nobody seems to remember it.
I suspect that greasweazle appeals because it's cheap. There's also
Kyroflux, DeviceSide, FluxEngine...using MCU based designs.
I am not going to try any of them. I just hope I can find some way to
restore RS232 communications on this machine. As it is, I can neither
do real work nor hobbies.
The idea's the same. What I'm a bit surprised about is that there has
been no emulation of a generic floppy controller offered. It can't be
that complex; if I recall correctly the NEC 765 only used 1100 words of
microcode.
I know the microcode for the DEC RX01 (FM only) which was published in
the printset and the RX02 (FM and M2FM) which was never published but
which I disassembled and commented were not hard to understand.
-tony
12:20 p.m.
On Thu, 18 May 2023, Chuck Guzis via cctalk wrote:
The idea's the same. What I'm a bit
surprised about is that there has
been no emulation of a generic floppy controller offered. It can't be
that complex; if I recall correctly the NEC 765 only used 1100 words of
microcode.
That is exactly what I want. Fully transparent.
Full implementation of INT13h, 1Eh
plus the added functions of read/write a flux transition track,
and simple command line software for image/write image of entire disk.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
12:23 p.m.
Re: flux images.
Tony, There are flux images on the internet archive if you want to practice using them.
Sent from my iPhone
On May 18, 2023, at 12:20, Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
On Thu, 18 May 2023, Chuck Guzis via cctalk wrote:
The idea's the same. What I'm a bit
surprised about is that there has
been no emulation of a generic floppy controller offered. It can't be
that complex; if I recall correctly the NEC 765 only used 1100 words of
microcode.
That is exactly what I want. Fully transparent.
Full implementation of INT13h, 1Eh
plus the added functions of read/write a flux transition track,
and simple command line software for image/write image of entire disk.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
9:28 a.m.
I run the greaseweazle under window 10 and windows 11. I havent' seen
any problems as of yet but I am using the command line utilities mostly.
On 5/18/2023 10:48 AM, Tony Duell via cctalk wrote:
On Thu, May 18, 2023 at 3:16 PM Antonio Carlini via
cctalk
<cctalk(a)classiccmp.org> wrote:
At ~£25 you're unlikely to lose much with
either of the two front
runners :-)
Unfortunately in my case that is not true.
I ordered a Greaseweazle earlier today and downloaded the software. Of
course there is no such thing as documentation....
I read on the web site that to use it under Windows 8.1 I had to
install a device driver and to do that I needed a program called
'zadig.exe'. I downloaded that following the link on the Greaseweazle
page.
Now I don't yet have the Greaseweazle but I decided to just check that
the programs would run. They do not
The gw software itself falls over with a moan about a missing .dll.
The bit I recognise is 'stdio'. No idea where or how to get htat.
zadig was worse. I gave it permission to make changes but AFAIK didn't
ask it to change anything. None-the-less I've lost RS232
communications (the USB-serial cable was plugged in at the time). I
can find no way to get that to work again.
So I've lost the ability to program and read PALs and EPROMs. talk to
my palmtops, calcultors and other machines and so on. Bascially I
can't do much..
I wish I'd never listened to people who said this was easy and would work fine.
Never again.
-tony
9:32 a.m.
On Thu, May 18, 2023 at 5:28 PM Mike Katz <bitwiz(a)12bitsbest.com> wrote:
I run the greaseweazle under window 10 and windows 11. I havent' seen
any problems as of yet but I am using the command line utilities mostly.
I was running from the command line too. Typing 'gw' just gets a
dialogue box moaning that the program can't run because I don't have
some .dll or other.
But that's a minor issue. The loss of RS232 communications is a lot
more serious.
-tony
9:46 a.m.
On 5/18/23 09:32, Tony Duell via cctalk wrote:
On Thu, May 18, 2023 at 5:28 PM Mike Katz
<bitwiz(a)12bitsbest.com> wrote:
Maybe I should pass my design to you. As with my Pertec interface
controller, my disk version has the option to select either serial (TTL
level RS232 async) or USB (CDC ACM) interfaces (compile-time option).
Requires no special software on the host end.
File transfer is via YMODEM-1K, however. Maybe that's a stumbling block
for you.
But I forgot that you don't like building stuff.
--Chuck
I run the greaseweazle under window 10 and windows 11. I havent' seen
any problems as of yet but I am using the command line utilities mostly.
I was running from the command line too. Typing 'gw' just gets a
dialogue box moaning that the program can't run because I don't have
some .dll or other.
But that's a minor issue. The loss of RS232 communications is a lot
more serious.
17 May
17 May
9:11 p.m.
On Wed, May 17, 2023 at 8:49 PM Chuck Guzis via cctalk
<cctalk(a)classiccmp.org> wrote:
As much as Tony doesn't like it, I need to point
out that a modern MCU
quite often has as much (or more) RAM, and runs faster than many older
PCs. Consider, for example, the lowly STM32H7A3 series. 1.4MB of RAM,
2MB of program flash, 5 DMA controllers, ethernet, TFT LCD, up to 164 5V
tolerant GPIOs, USB OTG...I won't go on.
Now wait a second. I never said that in this thread. I said that I
know nothing about them.
I am NOT, repeat NOT, contemplating wiring up a load of TTL or AM2900
bit slice chips or... to make a floppy controller or a flux transition
time recorder. I am happy to use a microcontroller. But as I know
nothing about them I am looking for a solution that 'works'. I do not
want to start having to rewrite the firmware.
Why tinker around with a PC when your MCU is more powerful? I store my
retrieved data on a 32GB SD card.
I enjoy classic computers which are simple enough for me to understand
and to get to do what _I_ want. This does not mean they're the only
thing I consider for solving a problem.
-tony
5:25 p.m.
On Wed, May 17, 2023 at 12:02:05PM -0500, Mike Katz via cctalk wrote:
That is because Amiga uses GCR recording rather then
FM or MFM.
Nope. You may have gotten confused with the Commodore 64 drives, which
were very Special, or perhaps early Apple gear.
The Amiga's disk controller supports both GCR and MFM, but MFM was used by
default because it is higher-density and the blitter can be used to perform
MFM decoding. It can read and write PC disks just fine using a third-party
block device driver (one was later bought-in and shipped with Workbench),
but the native format uses a different sector scheme which gets 880kiB on a
DD disk instead of the usual 720kiB of the PC.
Said third-party device drivers are flexible enough that they'll handle
disks from other platforms which use PC-compatible disk controllers such as
the Atari ST, Acorn Archimedes, Sun workstations, and later Apple Macs.
The Amiga pretty much died before HD disks became standard, although some
Amiga-compatible HD drives exist and gave 1760kiB per disk. These were like
hen's teeth even back then. I have one and have never seen another.
6:38 p.m.
That is
because Amiga uses GCR recording rather then FM or MFM.
Nope. You may have gotten confused with the Commodore
64 drives, which
were very Special, or perhaps early Apple gear.
The Amiga's disk controller supports both GCR and MFM, but MFM was used by
default because it is higher-density and the blitter can be used to perform
MFM decoding. It can read and write PC disks just fine using a third-party
block device driver (one was later bought-in and shipped with Workbench),
but the native format uses a different sector scheme which gets 880kiB on a
DD disk instead of the usual 720kiB of the PC.
Said third-party device drivers are flexible enough that they'll handle
disks from other platforms which use PC-compatible disk controllers such as
the Atari ST, Acorn Archimedes, Sun workstations, and later Apple Macs.
The Amiga pretty much died before HD disks became standard, although some
Amiga-compatible HD drives exist and gave 1760kiB per disk. These were like
hen's teeth even back then. I have one and have never seen another.
It's an easy, and common, mistake to make, . . .
Almost all other MFM formats use a track and sector layout based on what
was developed by IBM, long before the PC. Traditionally, it was called
"IBM format", but for the last 42 years, that name has only added to the
confusion, because most people who were NOT in computers more than 40
years ago will mistakenly assume that the name is referring to IBM PC.
To avoid that confusion, I call it "IBM/WD" format, which is less
ambiguous, since although IBM developed the style of format, Western
Digital had a major part in making it ubiquitous.
The Amiga is MFM, but does not follow the IBM/WD format "standard".
The NEC 765 FDC has trouble with it, because the NEC is looking for IBM/WD
sectors and tracks. The NEC FDC can be TRICKED into reading it. Part of
that involves changing drive select in mid-read.
In the relatively early days, Amiga came out with a 5.25" drive and
software to emulate PC! It was close enough in compatability to be able
to run XenoCopy (once called "the acid test of compatability"!) and read
SOME formats. But, people were displeased with the performance; it was as
slow as an AT. They got the elephant to fly!, but people complained about
the speed and payload.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
24 May
24 May
2:26 a.m.
On Wed, May 17, 2023 at 5:29 AM Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
Last time that I tried to research it, I found that
there had once been an
external drive in which the USB and controller werenot integrated with the
drive electronics, so that it could easily get a different drive
connected. It is, of course, not available anywhere.
I also saw a datasheet for a chip that was a USB floppy controller! It
also does not seem to be available.
I have looked in my collection and found 2 external floppy drives with
USB interfaces. Both, not surprisingly, are single 3.5" 1.4M units
One contains a USB floppy drive. That is, after removing the plastic
casing there's a disk drive inside only. The USB cable disappears into
that. After removfn the top shielding cover from that, there's a tiny
PCB with an ASIC on it. USB goes to that, so do the head connections.
So all in one chip, probably not hackable
The other drive is more interesting. There's a drive mechanism and a
little PCB hung off the back. These are connected by a tapewire type
of ribbon cable, I suspect (but have NOT done any tests yet, so this
is a guess) that this is the interface used on some later laptop
floppy drives -- that is much the same signals as on a Shugart floppy
interface. The little PCB has the USB cable soldered to it. And 2 ICs.
Alas some spoilsport has removed the numbers from them. One (14 pins)
is probably a TTL buffer to drive the disk drive signals. The other
(still an SMD dual-in-line package but closer pin pitch than the SOIC
of the other chip) is presumably a USB floppy controller. When I have
time I'll probe things and see if I can figure it out.
-tony
2:54 a.m.
On 2023-05-24 05:26, Tony Duell via cctalk wrote:
On Wed, May 17, 2023 at 5:29 AM Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
Some of the USB<->Floppy drives used the SMSC USB97CFDC like chips.
Which basically was an 8051, USB and a 765 FDC in a chip ...
Last time that I tried to research it, I found
that there had once been an
external drive in which the USB and controller werenot integrated with the
Alas
some spoilsport has removed the numbers from them. One (14 pins)
is probably a TTL buffer to drive the disk drive signals. The other
(still an SMD dual-in-line package but closer pin pitch than the SOIC
of the other chip) is presumably a USB floppy controller. When I have
time I'll probe things and see if I can figure it out.
3:02 a.m.
On Wed, May 24, 2023 at 10:54 AM emanuel stiebler <emu(a)e-bbes.com> wrote:
On 2023-05-24 05:26, Tony Duell via cctalk wrote:
Unfortunately the data sheets for that series say that said chips come
in a 100 pin PQFP package. This things has a lot few pins and only on
2 sides of the package. So not that.
-tony
On Wed, May 17, 2023 at 5:29 AM Fred Cisin via
cctalk
<cctalk(a)classiccmp.org> wrote:
Some of the USB<->Floppy drives used the SMSC USB97CFDC like chips.
Which basically was an 8051, USB and a 765 FDC in a chip ...
Last time that I tried to research it, I found
that there had once been an
external drive in which the USB and controller werenot integrated with the
Alas
some spoilsport has removed the numbers from them. One (14 pins)
is probably a TTL buffer to drive the disk drive signals. The other
(still an SMD dual-in-line package but closer pin pitch than the SOIC
of the other chip) is presumably a USB floppy controller. When I have
time I'll probe things and see if I can figure it out.
17 May
17 May
3:45 a.m.
On 17/05/2023 04:56, Tony Duell via cctalk wrote:
EXACTLY! I was told that was the best solution for
this sort of thing.
Are there any downsides to doing it that way?
If I do go that route, what are the options? I have no knowledge of
them and thus no preference for one over another
As I said at the start I am clueless about this. I really need
somebody to talk me through it, what to get, what to build, what to
download etc.
As I suspect that you have IBM PC compatible systems with 5.25" (high
and normal density) and 3.5" (ditto) then I would think the easiest
solution for you is to run DOS on such a machine and use Dave Dunfield's
ImageDisk: http://dunfield.classiccmp.org/img/index.htm. This assumes
you have some way to get files (specifically IMD files) onto and off
that system ... perhaps through a network connection? My preferred
solution is to boot to DOS using a CF adapter and then - when finished
imaging - to connect that CF card to a USB card reader that supports CF
and is connected to a more modern machine for archiving, storage of the
image or whatever.
This all depends on the FDC on whatever motherboard you have being
capable of reading/writing all the modes that you myriad collection
requires (or at least the subset you want to use in this manner).
TESTFDC (part of the ImageDisk package) will tell you exactly which
modes work and don't work with your hardware.
I do also have a FluxEngine that I want to get around to using - see
http://cowlark.com/fluxengine/index.html for a list of formats it
supports natively. The advantage would be that you are not limited by
the PC FDC as the FluxEngine will read flux transitions directly from
the connected floppy disk. FluxEngine connects via USB to whatever
modern system you choose to use. However, getting the Cypress PSoC5LP
dev board might be a challenge right now given the continuing global
supply shortage. FluxEngine supports IMD.
If you want to put a random file on a floppy for something obscure then
you need to find software (or a chain of software) that will build an
IMD file. DOS will be easy, CP/M is probably simple enough, but after
that I expect that you'll potentially need to do some digging for each
new format.
Antonio
--
Antonio Carlini
antonio(a)acarlini.com
16 May
16 May
9:52 p.m.
On 5/16/2023 4:05 PM, Dennis Boone via cctalk wrote:
David has already connected with me, and I am grateful to send the unit
to him to see if he can retrieve anything. And yes, once the data is
off the drive, creating a decoder should not be overly difficult.
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
At the most
recent CoCoFEST!, I brought home the old Glenside Club
Computer Hard Drive. The mechanism is an ST-251, and I was wondering
if someone on-list would be willing to attempt to pull data off the
drive. I have no ability to configure to read this drive type, and
the data is not precious or anything, I just though we should try to
pull it off for historical sake.
The best way to approach this, given the interchange issues with MFM
disk controllers, is probably to use one of Dave Gesswein's MFM Emulator
devices. It'll give you a flux image that can then be decode.
There may not be a decoder for the CoCo format yet, but it's probably
not too far different from other common things, so hopefully it could be
constructed fairly easily. The MFMEmu community seems to be willing to
help with this.
De 
2:43 p.m.
Jim,
I would ask on here:-
https://groups.google.com/d/forum/mfm-discuss
to see if any one has one of these
https://www.pdp8online.com/mfm/mfm.shtml
which will image an MFM disk so you are not re-reading and probably damaging your
original, an can then analyse the content at your leisure
Dave
-----Original Message-----
From: Jim Brain via cctalk <cctalk(a)classiccmp.org>
Sent: Tuesday, May 16, 2023 4:16 AM
To: General Discussion: On-Topic and Off-Topic Posts <cctalk(a)classiccmp.org>
Cc: Jim Brain <brain(a)jbrain.com>
Subject: [cctalk] ST-251 Data Recovery for Glenside Color Computer Club (GCCC)
At the most recent CoCoFEST!, I brought home the old Glenside Club Computer
Hard Drive. The mechanism is an ST-251, and I was wondering if someone on-
list would be willing to attempt to pull data off the drive.
I have no ability to configure to read this drive type, and the data is not precious
or anything, I just though we should try to pull it off for historical sake. I was not
in the club when teh drive was in use, so I do not know what could be on it. I
assume BBS data, but it could be anything.
Happy to post to someone who wants to give it a go. If the drive needs to be
destroyed to get the data, or if attempting to read the data destroys the drive, I
will not hold anyone responsible. I don't even need the drive back, just data if it
is recoverable.
Jim
--
Jim Brain
brain(a)jbrain.com
www.jbrain.com
9:52 p.m.
On 5/16/2023 4:43 PM, dave.g4ugm(a)gmail.com wrote:
Jim,
I would ask on here:-
https://groups.google.com/d/forum/mfm-discuss
to see if any one has one of these
https://www.pdp8online.com/mfm/mfm.shtml
which will image an MFM disk so you are not re-reading and probably damaging your
original, an can then analyse the content at your leisure
That was my thought as well. Image the raw data, and then work on
decoding. Dave Gesswein already reached out.
Jim
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18 participants
participants (18)
-
Antonio Carlini -
ben -
Chuck Guzis -
dave.g4ugm＠gmail.com -
Dennis Boone -
emanuel stiebler -
Ethan Dicks -
Fred Cisin -
geneb -
Jim Brain -
Kenneth Gober -
Liam Proven -
Mike Katz -
Peter Corlett -
Scott LaBombard -
Tony Duell -
Warner Losh -
Wayne S