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Sector Skew Macro for 3.5" 1.44mb diskette on a ZFDC

Hello Everyone,

Compupro CPUZ
Compupro RAM17
Compupro System Support 1
Dual IDE CF (as Drive A and B)
ZFDC (with 5.25 and 3.5" disks as C and D)

I am now modifying my BIOS to allow for using a 1.44mb 3.5" diskette on my ZFDC.   Looking at the Disk Parameter Header in the HFL3.ASM file I have referenced the proper Drive Parameter Table (CPM144) but there is one piece still missing.

It is what CPM3 refers to as the 'Sector Skew Macro' for this format disk.  Here are the two formats that John has included in the original files for 8" and 5.25" drives:

SD128$trans:    skew    26,6,0                ;8" sector skew (Note first sector is 0)
DD512$trans:    skew    16,4,0                ;5" sector skew (16 = 8X2)

I will need something like this:

CPM144$trans:    skew    36,???,0         ;3.5" sector skew (36 = 18 sectors per track X 2 sides, sector count starts with 0)

The part with the ??? is what I need and described here in the CPM System manual:

SKEW Macro
The SKEW macro generates a skew table and requires the following parameters: the number of physical sectors per track, the skew factor, and the first sector number on each track (usually 0 or 1).

The form of the SKEW macro call is label: SKEW ?secs,?skf,?fsc where:

is the number of physical sectors per track;
is the sector skew factor;
is the first sector number on each track.

So, what do I need for the sector skew factor?