|One possibility... connect the drive via a usb adapter (which can be connected "after" the system has boot up as per norm)?|
Another "might" be to use a Knoppix/Ubuntu cd (Linux variants on a CD). Boot system with that - set CD to first boot item. Drive can be there as Slave to first Master; possibly even as sole drive - temp installed as Primary Master? One may then be able to access the drive's contents via either config?
Another possible temp solution might be to install drive as Secondary Master - with/without a Slave (CD etc.)? Leave system to boot off First/Primary Master. In this case ensure that jumpers are all correct - especially if you move or change CD status?
If you can get a copy of the Sysinternals ERD Commander (last Sysinternal published version was 2005) you may be able to use that to access/recover data etc; and maybe also fix the problem? It's now part of M$-land and they haven't made a more recent version than ERD2005; but appear to have buried "their" latest version of it all in a utilities pack only available to TechNet Registered manufacturers or similar.
Barts PE(?) Bootdisk is said to be very simlar too these days; so perhaps it may suffice - and that is (free?) at least available to all...