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Reading CP/M disks

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Prime

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Feb 12, 2012, 7:50:45 AM2/12/12
to
Hi all,

I have some CP/M disks that where formatted on a BBC Z80 second processor
running Opus DDCPM. I have booted up the original system and can read the
diks on there without problems, vut would like to be bale to get the
files off them to something more modern.

The files I'm trying to extract are mostly either wordstar documents or
Z80 and 6502 source files.

Now the oddball thing about theese CP/M disks is that the first couple of
tracks are FM / Single density whilst the rest of the disk is MFM /
Double density.

I have available to me a machine that I can boot into PC-DOS, Windows 98,
Windows XP or Linux.

I can scan the disks with Anadisk, and am able to read them on the PC's
5.25" 1.2MB drive, and have tried using the dump command within Anadisk
to make a raw dump of one of the disks, which seemed to work ok.

So is it possible to write a disk def for something like 22Disk or
cpmtools to read the data off these disks.

The specific details of the format I have availabe to me are :

> Double density discs formatted with DDCPM:
>
> Tracks 0-2 formatted Single Density
> Tracks 3-159 formatted Double Density
>
> Single density tracks are 10 x 256 byte sectors per track
> Sector skew of 2
>
> Double Density tracks are 10 x 512 byte sectors per track
> Sector skew of 1
> Sector interleave of 2
>
> CP/M allocation unit block size of 4k
> 256 Directory entries (filenames)

Cheers.

Phill.

Julian Smith

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Feb 12, 2012, 8:45:29 AM2/12/12
to
On 12/02/2012 12:50, Prime wrote:
> Hi all,
>
> I have some CP/M disks that where formatted on a BBC Z80 second processor
> running Opus DDCPM. I have booted up the original system and can read the
> diks on there without problems, vut would like to be bale to get the
> files off them to something more modern.
>
> The files I'm trying to extract are mostly either wordstar documents or
> Z80 and 6502 source files.
>
> Now the oddball thing about theese CP/M disks is that the first couple of
> tracks are FM / Single density whilst the rest of the disk is MFM /
> Double density.
>
> I have available to me a machine that I can boot into PC-DOS, Windows 98,
> Windows XP or Linux.
>
> I can scan the disks with Anadisk, and am able to read them on the PC's
> 5.25" 1.2MB drive, and have tried using the dump command within Anadisk
> to make a raw dump of one of the disks, which seemed to work ok.
>
> So is it possible to write a disk def for something like 22Disk or
> cpmtools to read the data off these disks.
>
It's possible. if your PC floppy controller can format and write the
single density FM tracks. None of my recent PC's have successfully
formatted single density tracks but will read / write them. Your mileage
may vary...
Dave Dunfield's TESTFDC will test formatting / writing / reading single
density and confirm if your PC is capable of all three.

I've had good results using OmniFlop and an old Adaptec 1540CF ISA card
which does support single density writing / formatting.

Julian

Julian Smith

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Feb 12, 2012, 9:01:18 AM2/12/12
to
Just realised I'd not read the question properly completely missed the
point, as you're not trying to write them back out...
Don't know about 22disk or cpmtools but the file system layout won't be
that complicated (e.g. probably contiguous files) so have you tried the
simple approach of opening the disk image using the old MSDOS EDIT (in
binary mode) and simply scanning through for something that looks like
the start of a file you want and copy / paste it out?

Julian

David Schultz

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Feb 12, 2012, 9:33:47 AM2/12/12
to
On 02/12/2012 06:50 AM, Prime wrote:
> So is it possible to write a disk def for something like 22Disk or
> cpmtools to read the data off these disks.
>


If you had posted this around April of last year I might have been more
help. That was when I used cpmtools to read in all of my old CP/M-68K
floppies.

Digging out my notes I see that I had quite a bit of trouble with
cpmtools even without a density change. It looks like my final solution
was to use fdutils and simply use dd to copy the disk to a file. After
which I used cpmtools on it.

So I think what you could do is use setfdprm (from fdutils) to set the
drive parameters for the DD format. Then use dd with an offset to skip
the SD sectors, pretending that they are DD of course. Then copy.


http://www.fdutils.linux.lu/

Ole Christensen

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Feb 12, 2012, 10:43:10 AM2/12/12
to
on 02/12/2012 01:50 PM, Prime wrote:

> Now the oddball thing about theese CP/M disks is that the first
> couple of
> tracks are FM / Single density whilst the rest of the disk is MFM /
> Double density.

The FM part are only used for boot,... no files in there,...

---snip---

> So is it possible to write a disk def for something like 22Disk or
> cpmtools to read the data off these disks.

Try some of those build-ins in 22disk,...
(read only)

the hard thing will be to figure out the scheme for
the 2 sides, these are: ORDER SIDES, ORDER CYLINDERS
and / or ORDER EAGLE,...
<ole>

BEGIN PIE1 Pied Piper - DSDD 96 tpi 5.25"
DENSITY MFM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,512
SIDE1 0 1,3,5,7,9,2,4,6,8,10
SIDE2 1 1,3,5,7,9,2,4,6,8,10
ORDER SIDES
BSH 4 BLM 15 EXM 0 DSM 391 DRM 255 AL0 0F0H AL1 0 OFS 3
END

BEGIN LOB4 Lobo Max-80 (512 bytes/sector) - DSDD 96 tpi 5.25"
DENSITY MFM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,512
SKEW 2
SIDE1 0 0,1,2,3,4,5,6,7,8,9
SIDE2 1 0,1,2,3,4,5,6,7,8,9
ORDER SIDES
BSH 4 BLM 15 EXM 0 DSM 391 DRM 255 AL0 0F0H AL1 0 OFS 3
END

BEGIN OTR2 Otrona Attache - DSDD 96 tpi 5.25"
DENSITY MFM ,LOW
CYLINDERS 80
SIDES 2
SECTORS 10,512
SKEW 2
SIDE1 0 1,2,3,4,5,6,7,8,9,10
SIDE2 1 1,2,3,4,5,6,7,8,9,10
ORDER CYLINDERS
BSH 4 BLM 15 EXM 0 DSM 386 DRM 127 AL0 0C0H AL1 00H OFS 3
END

Axel Berger

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Feb 12, 2012, 1:41:00 PM2/12/12
to
Prime wrote on Sun, 12-02-12 13:50:
> The files I'm trying to extract are mostly either wordstar documents
> or Z80 and 6502 source files.
>
> have tried using the dump command within Anadisk
> to make a raw dump of one of the disks, which seemed to work ok.

Those files are text. If you have a dump, wouldn't it be quickest and
easiest to extract them from there?

Bill Leary

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Feb 12, 2012, 8:02:48 PM2/12/12
to
"Axel Berger" wrote in message news:201202121...@b.maus.de...
I'm pretty sure the WordStar documents are not just text. I used NewWord in
my CP/M days and those files, saved as documents, had binary in them.

- Bill

glen herrmannsfeldt

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Feb 12, 2012, 8:28:09 PM2/12/12
to
Bill Leary <Bill_...@msn.com> wrote:

(snip)
> I'm pretty sure the WordStar documents are not just text. I used NewWord in
> my CP/M days and those files, saved as documents, had binary in them.

I just scanned a QX-10 WordStar manual, to send to bitsavers.

I was mostly scanning and not reading, but it looked like
everything was text.

I now have a running QX-10, but haven't tried running wordstar.

-- glen

Roger Ivie

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Feb 12, 2012, 9:08:40 PM2/12/12
to
On 2012-02-13, Bill Leary <Bill_...@msn.com> wrote:
> I'm pretty sure the WordStar documents are not just text. I used NewWord in
> my CP/M days and those files, saved as documents, had binary in them.

IIRC, the 8th bit is set on soft spaces, soft carriage returns, and the end of
a word.
--
roger ivie
ri...@ridgenet.net

Bill Leary

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Feb 13, 2012, 7:18:49 AM2/13/12
to
"Roger Ivie" wrote in message news:slrnjjgs58...@stench.no.domain...
>
> On 2012-02-13, Bill Leary <Bill_...@msn.com> wrote:
>> I'm pretty sure the WordStar documents are not just text. I used NewWord
>> in
>> my CP/M days and those files, saved as documents, had binary in them.
>
> IIRC, the 8th bit is set on soft spaces, soft carriage returns, and the
> end
> of a word.

Perhaps that was it. I had to transfer a number of files from a CP/M system
to a DOS system over a 2400bps serial link and it was noticeably faster to
copy as text as opposed to binary. If I copied NewWord and WordStar
documents to the DOS system as text they didn't look right when they got
there.

- Bill

Axel Berger

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Feb 13, 2012, 8:43:00 AM2/13/12
to
Bill Leary wrote on Mon, 12-02-13 02:02:
>and those files, saved as documents, had binary in them.

As long as it's just embedded and most of the file is legible text, you
can still find the beginning and the end and extract the file from the
dump, or reassemble it if fragmented.

jgharston

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Feb 13, 2012, 6:12:01 PM2/13/12
to
Prime wrote:
> I have some CP/M disks that where formatted on a BBC Z80 second processor
> running Opus DDCPM. I have booted up the original system and can read the
> diks on there without problems, vut would like to be bale to get the
> files off them to something more modern.

Image them with DiskToImg http://mdfs.net/Apps/DiskTools which I
updated
just last week to to mixed-format DDCPM disks, and then access the
files
with CPMFiler http://mdfs.net/Software/CPM

JGH

BobH

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Feb 13, 2012, 8:00:31 PM2/13/12
to
On 2/12/2012 7:08 PM, Roger Ivie wrote:
> On 2012-02-13, Bill Leary<Bill_...@msn.com> wrote:
>> I'm pretty sure the WordStar documents are not just text. I used NewWord in
>> my CP/M days and those files, saved as documents, had binary in them.
>
> IIRC, the 8th bit is set on soft spaces, soft carriage returns, and the end of
> a word.

That matches what I remember as well.

BobH

s100guy

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Feb 14, 2012, 12:18:16 AM2/14/12
to
On Feb 12, 4:50 am, Prime <a...@666aurigae.demon.co.uk> wrote:
> Hi all,
> .... <snip> .....
> Now the oddball thing about theese CP/M disks is that the first couple of
> tracks are FM / Single density whilst the rest of the disk is MFM /
> Double density.
>

Phil --

Definitely possible to write a 22disk definition of those diskettes.
Take a look at the Cromemco definitions supplied with the original
22disk software. Cromemco used the same dual-density layout on their
diskettes in order to maintain compatibility between their older, and
newer, floppy controller hardware. The trick comes in finding a
floppy controller that supports reading the single density part. Not
many of the newer controllers can handle that. Also, it doesn't
matter (as someone else said) that there is nothing interesting in the
single density tracks ("just the system"), because lots of the old
software tries to read them initially -- no matter what. So if it
does, and the FDC can't do single density, you're toast. I have a PC
here (thanks Kieth!) that will read Cromemco diskettes (with the dual
density thing) via 22disk, so it *can* be done. There may be easier
ways, however.
Roger

Phill Harvey-Smith

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Feb 16, 2012, 7:59:32 AM2/16/12
to
s100guy <rzh_...@yahoo.com> wrote in
news:69134a31-e0ec-499d...@kn4g2000pbc.googlegroups.com:

> On Feb 12, 4:50 am, Prime <a...@666aurigae.demon.co.uk> wrote:
>> Hi all,
>> .... <snip> .....
>> Now the oddball thing about theese CP/M disks is that the first
>> couple of tracks are FM / Single density whilst the rest of the disk
>> is MFM / Double density.
>>
>
> Phil --

Phill :)

> Definitely possible to write a 22disk definition of those diskettes.
> Take a look at the Cromemco definitions supplied with the original
> 22disk software. Cromemco used the same dual-density layout on their
> diskettes in order to maintain compatibility between their older, and
> newer, floppy controller hardware.

Yep managed to do it in the end (I'll paste the definition at the end of
this email).

> The trick comes in finding a
> floppy controller that supports reading the single density part. Not
> many of the newer controllers can handle that. Also, it doesn't
> matter (as someone else said) that there is nothing interesting in the
> single density tracks ("just the system"), because lots of the old

Yep have an old Athlon XP machine that I use for this sort of thing, I
chose it specificaslly because it's the most modern motherboard I have
that supports single density *AND* two floppy drives, based on the NForce
4 chipset IIRC. Also has IDE & SATA & SCSI (on an Adaptec card) plus card
reader for MMC/SD/CF etc, so deffo a media exchange PC :) :) :)


Anyway thanks for the usefull comments everyone.....

Here's the definitions incase they are usefull to anyone else....

BEGIN ACN1 Acorn CP/M on Acorn Z80 second processor.
DENSITY FM, LOW
CYLINDERS 80 SIDES 2 SECTORS 10,256
SIDE1 0 0,1,4,5,8,9,2,3,6,7
SIDE2 128 0,1,4,5,8,9,2,3,6,7
ORDER CYLINDERS
OFS 3
AL0 0C0H AL1 0
BSH 4 EXM 1 DSM 195 DRM 127 BLM 15
END

BEGIN ACN2 Acorn CP/M on Acorn Z80 second processor (Alternate).
DENSITY FM, LOW
CYLINDERS 80 SIDES 2 SECTORS 10,256
SIDE1 128 0,1,4,5,8,9,2,3,6,7
SIDE2 129 0,1,4,5,8,9,2,3,6,7
ORDER CYLINDERS
OFS 3
AL0 0C0H AL1 0
BSH 4 EXM 1 DSM 195 DRM 127 BLM 15
END

BEGIN ACN3 Sloger DDCPM on Acorn Z80 second processor.
DENSITY MFM, LOW
CYLINDERS 80 SIDES 2 SECTORS 10,512
SIDE1 128 0,2,4,6,8,1,3,5,7,9
SIDE2 129 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
OFS 3
AL0 0C0H AL1 0
BSH 5 EXM 3 DSM 195 DRM 255 BLM 31
END

BEGIN ACN4 Sloger DDCPM on Acorn Z80 second processor (alternate).
DENSITY MFM, LOW
CYLINDERS 80 SIDES 2 SECTORS 10,512
SIDE1 0 0,2,4,6,8,1,3,5,7,9
SIDE2 128 0,2,4,6,8,1,3,5,7,9
ORDER CYLINDERS
OFS 3
AL0 0C0H AL1 0
BSH 5 EXM 3 DSM 195 DRM 255 BLM 31
END

Cheers.

Phill.
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