" Finding out the data transfer rate
First, you need to find out the data transfer rate (roughly the density: high, double, single).
For this, you try out fdrawcmd readid 0 rate=x, where x is 0, 1, 2, 3 If no rate is supplied, fdrawcmd assumes rate=0 "
My question: How do the numbers 0,1,2, and 3 relate to the densities of high, double, and single? There are 4 numbers and only 2 densities.
Thanks Mark
On 02/23/2011 02:03 PM, Mark Hounschell wrote:
" Finding out the data transfer rate
First, you need to find out the data transfer rate (roughly the density: high, double, single).
For this, you try out fdrawcmd readid 0 rate=x, where x is 0, 1, 2, 3 If no rate is supplied, fdrawcmd assumes rate=0 "
My question: How do the numbers 0,1,2, and 3 relate to the densities of high, double, and single? There are 4 numbers and only 2 densities.
Thanks
Actually while I'm here, in addition to the above question, I've gone through the whole process and I'm still not exactly what the format is and how I can copy these floppies. Can I bother you all for some assistance please. Below are the steps and results I get. This is all being done on a 5.25" drive of a current (as possible) vintage and unknown media format. The media is labeld as DS DD.
Finding out the data transfer rate. (question above):
# fdrawcmd drive=/dev/fd1 readid 0 rate=1 need_seek track=0 0: 0 1: 0 2: 0 3: 0 4: 0 5: 6 6: 1 no disk change
I see byte 6 indicates a 256 byte sector. A rate of 1 means what density???
Finding out the number of sides (heads):
# fdrawcmd drive=/dev/fd1 readid 4 rate=1 need_seek track=0 0: 44 1: 1 2: 0 3: 0 4: 0 5: 6 6: 1 no disk change
Can I assume that the other side of the floppy has not been formatted?
Finding out how many cylinders there are, and how they are spaced:
# fdrawcmd drive=/dev/fd1 readid 4 rate=1 need_seek track=2 0: 4 1: 0 2: 0 3: 1 4: 1 5: 3 6: 1 no disk change
So my tracks are double spaced.
# fdrawcmd drive=/dev/fd1 readid 4 rate=1 need_seek track=80 0: 44 1: 1 2: 0 3: 27 4: 1 5: 3 6: 1 no disk change
ERROR
# fdrawcmd drive=/dev/fd1 readid 4 rate=1 need_seek track=78 0: 4 1: 0 2: 0 3: 27 4: 1 5: 1 6: 1 no disk change
So I guess I have 40 tracks??
Finding out the sector numbering scheme:
# fdrawcmd drive=/dev/fd1 readid 4 rate=1 need_seek track=78 repeat=20 0: 4 1: 0 2: 0 3: 27 4: 1 5: e 6: 1 no disk change
0: 4 1: 0 2: 0 3: 27 4: 1 5: 0 6: 1 no disk change
0: 4 1: 0 2: 0 3: 27 4: 1 5: 2 6: 1 no disk change
. . .
0: 4 1: 0 2: 0 3: 27 4: 1 5: c 6: 1 no disk change
0: 4 1: 0 2: 0 3: 27 4: 1 5: e 6: 1 no disk change
0: 4 1: 0 2: 0 3: 27 4: 1 5: 0 6: 1 no disk change
So does this mean I have 8 sectors per track? "0,2,4,6,8,a,c,e" or does this mean I have 8 sectors per track? "0,1,2,3,4,5,6,7" ????
With this information what would be the setfdprm command to enable me to dd the floppy to a file or another floppy??
Thanks for your patience. Regards Mark
Hi again Mark,
Actually while I'm here, in addition to the above question, I've gone through the whole process and I'm still not exactly what the format is and how I can copy these floppies.
Are you aware of the dskid command from http://www.seasip.demon.co.uk/Unix/LibDsk/ It may allow you to work at a higher level.
Cheers, Ralph.
Hi again Mark,
Actually while I'm here, in addition to the above question, I've gone through the whole process and I'm still not exactly what the format is and how I can copy these floppies.
Are you aware of the dskid command from http://www.seasip.demon.co.uk/Unix/LibDsk/ It may allow you to work at a higher level.
dskid can only identify disks with a filesystem I know about. But dskscan (part of the same package) may help to guess the format. Run it with a command like
% dskscan -format ibm360 /dev/fd0
(The format you specify is just to give dskscan a vague idea of the amount of tracks on the disc). If it works, you should get output like:
Cylinder 0 Head 0: Data rate: 250 Encoding: mfm Cyl 00 Head 0 Sec 1 size 512 Cyl 00 Head 0 Sec 2 size 512 Cyl 00 Head 0 Sec 3 size 512 Cyl 00 Head 0 Sec 4 size 512 Cyl 00 Head 0 Sec 5 size 512 Cyl 00 Head 0 Sec 6 size 512 Cyl 00 Head 0 Sec 7 size 512 Cyl 00 Head 0 Sec 8 size 512 Cyl 00 Head 0 Sec 9 size 512 Cylinder 0 Head 1: Found nothing Cylinder 1 Head 0: Data rate: 250 Encoding: mfm Cyl 01 Head 0 Sec 1 size 512 Cyl 01 Head 0 Sec 2 size 512 ...
What it does is repeatedly issue a READ ID command with all eight combinations of data rate and recording mode. If it finds something, it then issues repeated READ ID commands to list all the sector headers on each track.
On 02/23/2011 06:02 PM, John Elliott wrote:
Hi again Mark,
Actually while I'm here, in addition to the above question, I've gone through the whole process and I'm still not exactly what the format is and how I can copy these floppies.
Are you aware of the dskid command from http://www.seasip.demon.co.uk/Unix/LibDsk/ It may allow you to work at a higher level.
dskid can only identify disks with a filesystem I know about. But dskscan (part of the same package) may help to guess the format. Run it with a command like
% dskscan -format ibm360 /dev/fd0
(The format you specify is just to give dskscan a vague idea of the amount of tracks on the disc). If it works, you should get output like:
This looks very promising. I'll give it a shot later today.
Thanks Mark
Hi Mark,
For this, you try out fdrawcmd readid 0 rate=x, where x is 0, 1, 2, 3 If no rate is supplied, fdrawcmd assumes rate=0 "
My question: How do the numbers 0,1,2, and 3 relate to the densities of high, double, and single? There are 4 numbers and only 2 densities.
I don't know, so someone that does will hopefully pipe up, but it may be that
http://www.isdaman.com/alsos/hardware/fdc/floppy.htm#CCR
gives the answer with RAT0 and RAT1 since I think the number could just be passed to the FDC.
Cheers, Ralph.
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John Elliott -
Mark Hounschell -
Mark Hounschell -
Ralph Corderoy