8 Apr
2003
8 Apr
'03
9:52 a.m.
On Tue, 8 Apr 2003, Joe wrote:
The controller is full length and has XEBEC chips
and a Z-80 CPU.
I'm sure that it's MFM. It's marked IBM and next to that is a paper
sticker that says #1501492. Also marked IBM 6135984 in copper foil. My
diagnostic tool shows four settings in the ROM, the 10Mb drive is
third setting. I didn't look at the capacity of the other settings.
It's running this drive as a 10 Mb MFM drive but the drive is rated as
a 32Mb RLL capable drive.
my controller is an original IBM 10 Mb MFM HD
controller. It's only
using 10 Mb of the drive.
Near the middle of the board are 8 solder pads. By jumpering those (they
are the right size for a 4 position dip switch), you can get the
controller to use the other setting that are in its ROM. The 4 positions
are 2 for each drive, resulting in 4 possible combinations for each
drive. 10M, the default, is both switches open.
OR, there are software ways tio override the controller -
check with Steve Thatcher.