Disk compression gone wrong.
I had a number of files from a hard drive to save to floppies. Even compressed
it took 3 floppies.
Al was fine until one night, I was carrying the box of these and other floppies.
As I got out of the car, I dropped several disc and before I could stop, my
foot came do
On Thu, 3 Nov 2022 at 23:52, Fred Cisin via cctalk
wrote:
>
> Such as the classic Montezuma Micro CP/M for TRS80 Model 3, with "JOHN,
> EAT SHIT AND DIE" in some sectors?
?!
Do tell...
--
Liam Proven ~ Profile: https://about.me/liamproven
Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmai
On Thu, 3 Nov 2022 at 23:47, Grant Taylor via cctalk
wrote:
>
> Please expand "GCR".
Group-coded recording.
https://en.wikipedia.org/wiki/Group_coded_recording
Specifically:
https://en.wikipedia.org/wiki/Group_coded_recording#Apple
As opposed to Modified Frequency Modulation:
https://en.wikipe
On 11/4/22 2:56 AM, Christian Corti via cctalk wrote:
Short answer: ImageDisk
ACK
For FAT/DOS disks, I have a small script that creates both an .imd file
and a .zip file of the disk contents,
Nice!
I think that's in the same ball park as I would have assumed I'd do if
someone had asked me
On Thu, 3 Nov 2022, Grant Taylor wrote:
GCR is Group Code Recording, used on the Apple II, Commodore 1541 drive and
Amiga (and others) use a different encoding scheme than the normal FM
No, the Amiga can handle GCR, but never used it. It's plain standard MFM
with different sector layout and ID
On Thu, 3 Nov 2022, Fred Cisin wrote:
GCR stands for "group Coded Record"
group coded "recording" ;-)
Christian
On Thu, 3 Nov 2022, Fred Cisin wrote:
On Thu, 3 Nov 2022, Grant Taylor via cctalk wrote:
Please expand "GCR".
Sure, . . . (GROSSLY OVER-SIMPLIFIED, such as "pulse" instead of flux
transition)
FM is "frequency modulated". Well, it is actually a regular clock pulse,
[...]
MFM is "Modified
On Thu, 3 Nov 2022, Grant Taylor wrote:
Does anyone have a 101 level boot strap guide for someone wanting to get into
creating better-than-dd disk images?
I'm finding myself back in a position where I want to image / preserve
multiple 5¼ & 3½ inch disks. I think all of them are PC compatible
I would recommend a Greaseweazle. This is a flux change recorder/copier
that can handle many many different formats because it reads and writes
by flux transitions on the disk, regardless of the encoding scheme (GCR,
MFM, FM, etc.) or format.
This is how I format and copy DEC RX01 and RX02 8"
On Thu, 3 Nov 2022, Mike Katz via cctalk wrote:
GCR is Group Code Recording, used on the Apple II, Commodore 1541 drive and
Amiga (and others) use a different encoding scheme than the normal FM
(Frequency Modulation) or MFM (Modified Frequency Modulation) encoding
formats used by a majority of
GCR is Group Code Recording, used on the Apple II, Commodore 1541 drive
and Amiga (and others) use a different encoding scheme than the normal
FM (Frequency Modulation) or MFM (Modified Frequency Modulation)
encoding formats used by a majority of floppy disk controllers.
There is a very good d
Here's something right out of the Apple II FAQ:
07.007 Can I read Apple II diskettes on my PC?
Yes. There is a way for some PCs to read Apple II DOS 3.3 and
ProDOS 5.25"
floppies which are not copy-protected.
By "some PCs" I mean that the PC must have two floppy drives (only one ha
On Thu, 3 Nov 2022, Sellam Abraham via cctalk wrote:
There was a project someone did years ago where you can read GCR disks in
an unmodified PC drive by first inserting a PC formatted disk to get synced
and then swapping in a GCR encoded disk, then it can actually read the raw
pulses and they get
Fred,
There was a project someone did years ago where you can read GCR disks in
an unmodified PC drive by first inserting a PC formatted disk to get synced
and then swapping in a GCR encoded disk, then it can actually read the raw
pulses and they get decoded in software. I forget the website wher
> On Nov 3, 2022, at 7:38 PM, Fred Cisin via cctalk
> wrote:
>
> On Thu, 3 Nov 2022, Paul Koning via cctalk wrote:
>> An example of a non-PC format 5.25 inch disk that normal drives can read
>> would be the DEC RX50 floppy, which has 10 sectors per track rather than the
>> PC standard 9 sec
On Thu, 3 Nov 2022, Paul Koning via cctalk wrote:
An example of a non-PC format 5.25 inch disk that normal drives can read
would be the DEC RX50 floppy, which has 10 sectors per track rather than
the PC standard 9 sectors. But a standard drive will read and write
those just fine, if it's told
On 11/3/22 5:07 PM, Dennis Boone via cctalk wrote:
There aren't that many platforms that used CLV drives. I don't
recall seeing one in the PC world. If anyone did, they would have
been specialty stuff.
ACK
I haven't seen a flux imaging system for Zip/Jaz drives. MO stuff
might be easier o
> On Nov 3, 2022, at 5:57 PM, Glen Slick via cctalk
> wrote:
>
> On Thu, Nov 3, 2022 at 2:08 PM Grant Taylor via cctalk
> wrote:
>>
>> Hi,
>>
>> n00b alert
>>
>> Does anyone have a 101 level boot strap guide for someone wanting to get
>> into creating better-than-dd disk images?
>>
>> I'
GCR stands for "group Coded Record"
On Thu, 3 Nov 2022, Fred Cisin via cctalk wrote:
Also GCR, not MFM. NOT readable with a PC FDC.
On Thu, 3 Nov 2022, Grant Taylor via cctalk wrote:
Please expand "GCR".
Sure, . . . (GROSSLY OVER-SIMPLIFIED, such as "pulse" instead of flux
transition)
> Is Constant Linear vs Angular Velocity (?) anything I need to worry
> about when sticking within the IBM PC compatible line from say '90
> forward?
On Thu, 3 Nov 2022, Dennis Boone via cctalk wrote:
There aren't that many platforms that used CLV drives. I don't recall
seeing one in the PC wo
Also GCR, not MFM. NOT readable with a PC FDC.
On Thu, 3 Nov 2022, Grant Taylor via cctalk wrote:
Please expand "GCR".
Sure, . . . (GROSSLY OVER-SIMPLIFIED, such as "pulse" instead of flux
transition)
FM is "frequency modulated". Well, it is actually a regular clock pulse,
with data bit
> Is Constant Linear vs Angular Velocity (?) anything I need to worry
> about when sticking within the IBM PC compatible line from say '90
> forward?
There aren't that many platforms that used CLV drives. I don't recall
seeing one in the PC world. If anyone did, they would have been
specialty
> Is there a reason to do a real IMAGE backup, rather than a file
> backup?
On Thu, 3 Nov 2022, Dennis Boone via cctalk wrote:
People have occasionally found interesting things in the unallocated
sectors of disks. For garden variety PC format disks, it's not
necessary to do flux imaging to pre
> Is there a reason to do a real IMAGE backup, rather than a file
> backup?
People have occasionally found interesting things in the unallocated
sectors of disks. For garden variety PC format disks, it's not
necessary to do flux imaging to preserve that sort of thing, though. A
regime using a
On 11/3/22 4:35 PM, Fred Cisin via cctalk wrote:
Also GCR, not MFM. NOT readable with a PC FDC.
Please expand "GCR".
--
Grant. . . .
unix || die
On 11/3/22 3:57 PM, Glen Slick via cctalk wrote:
If they are 5¼ & 3½ inch disks which are not copy protected and
are readable with standard PC compatible floppy controllers, but not
necessarily limited to standard DOS formats, and you had a older PC
with a floppy controller which you could set
On Thu, 3 Nov 2022, Sellam Abraham via cctalk wrote:
Fred,
The Victor/Sirius 9000 was sort of PC compatible and featured a varial
speed floppy format, no?
Although MS-DOS capable, the Victor/Sirius 9000 was FAR from PC
compatible!
An amazing machine, but NOT PC compatible.
It is an ideal exa
But, why do IMAGING on PC-DOS disks?
On Thu, 3 Nov 2022, Grant Taylor via cctalk wrote:
My /personal/ and primary use case is for use in virtual machines where disk
images (a la dd) is best (in my experience).
THAT is a totally valid reason for disk images, rather than file copies.
Another,
Fred,
The Victor/Sirius 9000 was sort of PC compatible and featured a varial
speed floppy format, no?
Sellam
On Thu, Nov 3, 2022 at 3:09 PM Fred Cisin via cctalk
wrote:
> >> Note that some disk types are CLV, not CAV (e.g. some Mac disks), and
> >> reading them without additional hardware supp
Note that some disk types are CLV, not CAV (e.g. some Mac disks), and
reading them without additional hardware support may be problematic.
On Thu, 3 Nov 2022, Grant Taylor via cctalk wrote:
Is Constant Linear vs Angular Velocity (?) anything I need to worry about
when sticking within the IBM PC
On 11/3/22 3:27 PM, Dennis Boone via cctalk wrote:
Some people are bothered by Kryoflux's behavior around openness of
their formats and the like. I _think_ they've addressed that, but
if you care about this, you will have to verify.
Ya. I'm starting to see that.
I don't /personally/ care ab
On Thu, Nov 3, 2022 at 2:08 PM Grant Taylor via cctalk
wrote:
>
> Hi,
>
> n00b alert
>
> Does anyone have a 101 level boot strap guide for someone wanting to get
> into creating better-than-dd disk images?
>
> I'm finding myself back in a position where I want to image / preserve
> multiple 5¼ & 3
On 11/3/22 3:26 PM, Tomasz Rola via cctalk wrote:
I am (slowly) on my way to use ddrescue for similar thing(s).
I've used ddrescue for a /few/ of my disk images. Thankfully /most/ of
the 3½ disks that I've imaged have not needed ddrescue / SpinRite / et al.
--
Grant. . . .
unix || die
On 11/3/22 3:26 PM, Fred Cisin via cctalk wrote:
But, why do IMAGING on PC-DOS disks?
My /personal/ and primary use case is for use in virtual machines where
disk images (a la dd) is best (in my experience).
Why not just copy the files, and "ZIP" them?
Ziped (et al.) files are nice for so
On 11/3/22 16:07, Grant Taylor via cctalk wrote:
Hi,
n00b alert
Does anyone have a 101 level boot strap guide for someone
wanting to get into creating better-than-dd disk images?
Is there a reason to do a real IMAGE backup, rather than a
file backup? I have used Linux to backup a lot of ol
> I was thinking about acquiring a Kryoflux in the next few months and
> starting to collect better quality images of disks. I recently saw
> someone on Twitter suggest that Kryoflux wasn't the best route to go
> and suggested a SuperCard Pro instead.
Some people are bothered by Kryoflux's be
On Thu, Nov 03, 2022 at 03:07:00PM -0600, Grant Taylor via cctalk wrote:
> Hi,
>
> n00b alert
>
> Does anyone have a 101 level boot strap guide for someone wanting to get
> into creating better-than-dd disk images?
[...]
> So, does anyone have a 101 level boot strap guide for someone wanting to
On Thu, 3 Nov 2022, Grant Taylor via cctalk wrote:
Does anyone have a 101 level boot strap guide for someone wanting to get into
creating better-than-dd disk images?
I'm finding myself back in a position where I want to image / preserve
multiple 5¼ & 3½ inch disks. I think all of them are PC co
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