Uncreative Labs

Joined: 03 Feb 2006 Posts: 488 Location: pennsylvanai

there is some question regading swapping hard drives between systems.
with an XT or compatible, it's best to keep the controller and drives together as a set. exception: a newwer western digital bios will usually worl with a drive Low Level formatted with an older bios: even a "proprietary" bios.
a wd card will "see" a drive formatted weith a DTC xt controller. but the dtc xt card cannot see a drive formatted with a wd controller.

you can install a newer bios, preferably the "super formatter bios" supplied on most newer socketed cards. this will repl;ace the older, smaller proprietary bios.
a drive formatted with the older bios, as I said will be seen by ther newer chip. use disk utils carefully . at first.
when you put in a newer bios chip and DO NOT try a LOw Level format,
you need not change the jumpers on the drive table strip.
I believe this to be true... if you attempt a Low Level format the top jumper only , when used with a newer bios chip. will allow free format. meaning you type in the parameters and any mfm drive will work, even a st-4096
80 meg mfm. tjink 1024 cyl. 16 hds and 17( always) sectors

the Low level format of AT's and compatibles is incompatible with that of a xt. I recall when I was asked to work on a non-booting 286 early in 1990.
the controller was missing! I just installed another AT style controller and all was fine. You can generally swap cards in an AT. the newer cards with a wd1006 chip , are capable of a 1:1 interleave ( mush faster)
but will work fine if the original was a wd1003 ( 2:1)

beware the wd1007 is an esdi controller, same cables, different pinout
it will burn out either the card or the drive, so don't use it on mfm/rll drives

with an AT , many drives do not match the drive table in the cmos setup.
use any numbers lower than the maximum ( true/real) numbers of thje drive. You cannot change from 17 sectors. or swap heads and cylinders
like you can on IDE drives that will "translate"
just choose smaller heads and cyl than the total real numbers.

"clone bios" will work in genuine AT's. and sometimes the newer bios'
will provide more features as well, as an extended drive table.
avoid use of disk manager unless it is inconvenient to do otherwise.
there is a free program anydrive, that works.

sometimes the clone bios' will come from boards that are not true
clones and this may present compatibility problems.
many clone at's had the floppy controller built-in, i don't know if this represents a problem.