| Presented
by: Only On Saturday Night |
HiDensity Floppy Controller
Modification Update
I've successfully converted two
each WD1793 Floppy Disk Controller boards to Hi-Density.
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1 - I got a Fujitsu MB8877A to replace the WD1793.
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2 - I did the mods listed for Hi-Density controller conversion.
(Click button above)
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3 - I did a U10 mod, where the 4013 is replaced with a 74ls74+74ls04
combo.
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- This is needed if, your modified controller hangs up or
fails to do side 2.
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4 - I got a copy of CC3Disk, the one that has 3 occurences
of $1A00 and patched them to $3400.
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- Thanks to Mark Marlette.
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5 - I got a 1.2MB 5.25" drive and some Hi-Density disks to
try out.
With DMODE, /d1 was changed to: DMODE /d1 dns=3 cyl=50 sct=1E
t0s=1E sid=2
Then with Format: FORMAT /d1 r "HD80 Testing"
This gives 4,800 sectors or 1.2288 MB per 5.25" floppy.
Later, I got a 1.44MB 3.5" drive and changed it to: DMODE
/D2 dns=3 sct=20 t0s=20. This gives 1.31072MB on that floppy. Now I can
transfer files from/to my PC/NitrOS-9 floppies using the program OS9 in
a MS-DOS prompt window.
Here is that U10 MOD. Click on this small pix to get
larger one.
Here's two more proposed boards:
Left is a proposed HiDensity Board that you just plug
into your WD1793 controller after removing U1 and U7. Some flying wires
are needed. By jumper selection (JP2), it allows DS1 or DS2 or either,
for those of us who have two HD drives.
Right is a proposed 4013 replacement board, remove U10
and plug this into it's place.
