🚀 go-pugleaf

The old 40Mb MFM drive in my Z386/16 has just about given up the 
ghost.  So, I purchased a 120Mb Conner CP30104 IDE drive and IDE 
controller as a replacement.  After upgrading my BIOS from 2.1 to 
3.5, I installed everything.  I defined the drive as type 61 (as 
mentioned earlier in this group), FDISKed, and FORMATted the 
drive.  All this works fine. I can now boot from the new hard 
drive, etc.  

The strange thing is that the video is now messed up.  Characters 
are being dropped from the display.  If I type a row of charac-
ters, they look fine till I hit enter (or escape), the screen 
scrolls and the 25th and 41st characters vanish (along with a few 
other characters elsewhere on the screen).  I eventually wind up 
with several completely blank columns on the screen.  This is 
especially obvious when doing a directory.  Replacing the IDE 
controller with the old MFM controller and drive cures the video 
problem.  

Details 
Zenith 386/16 (vintage 1988, model ZBF-3339-EK)
CompuAdd 8 bit VGA controller with a Paradise chip (PVGA1A).  
ZDS BIOS 3.5 (p/n 444-549-11) 
     disk type 61       
     speed switch = fast (slow & smart show no difference)      
     video display = enhanced graphics (40x25 and 80x25 show
                no difference)  
memory = 2x Z-505 (1MB) cards
Identity IDE-220 IDE controller
new drive = Connor CP-30104 120Mb 
old drive = CDC (Imprimis) 94025-51 40Mb MFM (type 43)

I am guessing that there is some sort of memory conflict between 
the VGA card and the IDE BIOS.  Can anyone suggest what the cause 
of the problem might be and what can be done to cure it?

One last question, The sales people at the store where I bought 
the disk drive gave me the following specs on the drive.
size = 120Mb    cylinders = 1011
heads = 9       sectors = 26
precomp = 0     landing zone = 1011

This differs greatly from the description of drive type 61 in the 
BIOS.  Did the salesman screw up?  The drive does work when listed 
as a type 61.  

Cheers, Henk
colijn.1@osu.edu
-- 
============================================================================
Henk Colijn             The Ohio State University
colijn.1@osu.edu        Campus Electron Optics Facility
"Nothing is as inevitable as a mistake whose time has come."