Well, thanks much for the insight on the HDA vs. HDB recognition. After a little digging I found out this particular drive model has a known problem on the master/slave selection.
I enclose the specific note for those interested. I made the mod referred to in the article and the process is working now.
Thanks again,
Enrique
FROM
http://kharendaen.dyndns.org:8000/~henke/public/mk1214gap/
The Toshiba MK1214GAP appears to act as an IDE slave device when CSEL (pin 28 on the IDE bus) is driven high, even when the drive is jumpered as master. It is generally not a problem, as most non-cable-select systems pull CSEL low or allow it to float. Some, such as the Toshiba Libretto 50CT, drive CSEL high enough to cause the drive to misconfigure as slave.
One remedy for this is to short CSEL (pin 28) to a ground, such as the adjacent pin 30. This pulls CSEL low and forces the drive to correctly configure as master.
Similar issues (which respond to the above fix) have been reported for other drives (such as the Toshiba MK6409MAV and the Fujitsu MHN2300AT) in systems from various vendors.