abcscnge@csun.UUCP (Scott Neugroschl) (11/10/87)
We are trying to install a second hard disk in a true-blue IBM XT. We
have 2 10 MB hard disks, 2 Xebec controllers. We would like to install
both HD's on one controller, but we don't have the proper cabling, so we
are going to use 2 controller boards. Our problem is this: our in-house
technical support at work doesn't have the documentation, so when we install
both boards into our PC, they are both at the same I/O address and ROM address,
thereby causing an obvious contention lockup when drive C is accessed. How
do we set the ROM ADDR, I/O ADDR and OPTION jumpers to configure one drive
and controller as C and the other as D?
Thanks in advance...
--
Scott "The Pseudo-Hacker" Neugroschl
UUCP: {litvax,humboldt,sdcrdcf,rdlvax,ttidca,}\_ csun!abcscnge
{psivax,csustan,nsc-sca,trwspf }/mrc@CAM.UNISYS.COM.UUCP (11/13/87)
In article <879@csun.UUCP>, abcscnge@csun.UUCP (Scott Neugroschl) writes: > > We are trying to install a second hard disk in a true-blue IBM XT. We > have 2 10 MB hard disks, 2 Xebec controllers. We would like to install > both HD's on one controller, but we don't have the proper cabling, so we > are going to use 2 controller boards. Our problem is this: our in-house > technical support at work doesn't have the documentation, so when we install > both boards into our PC, they are both at the same I/O address and ROM address, > thereby causing an obvious contention lockup when drive C is accessed. How > do we set the ROM ADDR, I/O ADDR and OPTION jumpers to configure one drive > and controller as C and the other as D? > > Thanks in advance... > -- > Scott "The Pseudo-Hacker" Neugroschl > UUCP: {litvax,humboldt,sdcrdcf,rdlvax,ttidca,}\_ csun!abcscnge > {psivax,csustan,nsc-sca,trwspf }/ WHOA, WHOOPS, OOPS, and LOGICALGOTOHELL! You are up against more than a matter of plugging jumpers or twiddling dipswitches... You are up against the fundamentals of the IBM-PC architecture and ROMBIOS. You cannot! have two hard-disk controllers, not even two floppy-disk controllers, in any PC or PClone. The BIOS provides for ONLY ONE hard-disk-start interrupt vector and ONLY ONE floppy-disk-start interrupt vector. That is, only one each of the magic addresses in low-end memory which tell bios where to call with the parameters for a low-level I/O operation. Given that you do not want to rewrite the whole bloomin' BIOS, you can't get there ( 2 hd-controllers) from here (IBM PC). There are also other issues, like controller-alert-to-CPU interrupt numbers and vectors, and BIOS Parameter Block vectors, which might be manageable --which are managed by single-controller multi-type and multi-drive setups--but the controller-request vectors are the killers. OH Well... regardz, Ken