Re: Floppy image

The problem with that data *** is the unknown Gap3 and Gap4 information.
What is their for a 1.44meg 3.5" floppy?

Like I mentioned in my former posting, I did this about 20 years ago,
but incidentally I had the files with drive related definitions at
hand, here they
are for 3.5" HD and 5.25" HD drives with _256_ (not 512, I never made
that)
bytes per sector. I remember I had to experiment somewhat with the
gaps, years later I found out that the way I had set them still worked
fine on another drive which had 256 bytes per sector (a SCSI TEAC).

If you will implement also 256 bytes per sector - not that I can think
of a reason why - these might be of some use.

IFEQ \0!.$F0-FD35GA - this is the 3.5" drive
* DRIVE TYPE FD35F - 80 TRACKS,TWO SIDES,HIGH DENSITY
* USED TRACK 0-29 WHICH PROVIDE THE 512K MDOS CAN HANDLE
FCB $DF STEP RATE;HEAD UNLOAD TIME
FCB $02+.DMA HEAD LOAD TIME AND DMA BIT
FCB $40 .CD - THE MFM BIT
FCB \0!.$3 .U - PHYSICAL DRIVE NUMBER
FCB 1 .C - RE-RESTORE ALLOWED
FCB 1 .H - TWO HEADS
FCB $46 .R - LS PER SIDE
FCB 1 .N - (LS PER PHYSICAL SECTOR)-1
FCB $23 .EOT - PSN OF EOT (ONE SIDE,NO #0)
FCB $0E .GPL - GAP LENGTH
FCB $FF .DTL - N>0
FCB 0 OFFSET TO PHYSICAL TRACK 0
FCB 1 STEP COUNT MULTIPLYER
FCB 29 HIGHEST VALID TRACK NUMBER (I had these
drives partitioned...)
FCB 36 FORMAT MODE GAP LENGTH
FCB FDCLK$ CLOCK/SPEED SEL.
*
ENDC
......
*
IFEQ \0!.$F0-FD55GB - this is the 5.25 , IIRC with the
same values as the 3.5"
* DRIVE TYPE FD55GB - SECOND 40 TRACKS,TWO SIDES,360 RPM
FCB $DF STEP RATE;HEAD UNLOAD TIME
FCB $02+.DMA HEAD LOAD TIME AND DMA BIT
FCB $40 .CD - THE MFM BIT
FCB \0!.$3 .U - PHYSICAL DRIVE NUMBER
FCB 1 .C - RE-RESTORE ALLOWED
FCB 1 .H - TWO HEADS
FCB $34 .R - LS PER SIDE
FCB 1 .N - (LS PER PHYSICAL SECTOR)-1
FCB $1A .EOT - PSN OF EOT (ONE SIDE,NO #0)
FCB $0E .GPL - GAP LENGTH
FCB $FF .DTL - BYTES PER SECTOR
FCB 40 OFFSET TO PHYSICAL TRACK 0
FCB 1 STEP COUNT MULTIPLYER
FCB 79 HIGHEST VALID TRACK NUMBER
FCB 54 FORMAT MODE GAP LENGTH
FCB FDCLK$ CLOCK/SPEED SEL.
*
ENDC


Dimiter

------------------------------------------------------
Dimiter Popoff Transgalactic Instruments

http://www.tgi-sci.com
------------------------------------------------------


Ed wrote:
The problem with that data *** is the unknown Gap3 and Gap4 information.
What is their for a 1.44meg 3.5" floppy?


"David R Brooks" <davebXXX@xxxxxxxxxxxx> wrote in message
news:45965388$0$2655$5a62ac22@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Ed wrote:
Looking for a floppy image of a blank 1.44 floppy which includes all
header and gap information.


The data *** for National Semiconductor's PC8477 controller chip has
this information, in Fig. 4.1.

.

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