Possible to speed up I/O subsystem of 5150?

[Jim Leonard]

I have a few IBM model 5150s that I use to code entries for programming 
competitions and I'd like to try to speed up the hard disk in any way possible. 
(If you're curious what my last project was, check out 
http://www.pouet.net/prod.php?which=13722 to download and try it out -- it 
displays full-screen full-motion color video with sync'd sound -- yes, on a 
4.77MHz 8088, no fooling).  I've been looking for any way to speed up the hard 
disk subsystem (currently WD1002 with Seagate ST225) and I simply can't get 
more than 130KB/s out of the darn thing... so:

- Is there any MFM/RLL 8-bit ISA controller that can read disks at their full 
1:1 interleave?  If so, where can I get one?  3:1 is the best I've been able to 
get using the above MFM combination.  I haven't tried RLL yet because I don't 
have any RLL controllers.

- If not, do such things exist as 8-bit ISA IDE controllers?  I have lots of 
"little" IDE drives (320MB and 540MB models) that I could hook up.

I attempted not one but TWO 8-bit Plus hardcards (both 40MB models), thinking 
that the embedded drive/controller combo would be better, but my experience 
with Plus Hardcards (even the 16-bit 120MB versions) is that, after about 8 
years, the damn EEPROM forgets everything and it doesn't boot (no BIOS, get a 
1701 "controller error").  So I couldn't get either of them to work.  (As a 
result I have 4 Plus hardcards that I am *this close* to throwing away, unless 
someone has an idea of reviving them :-)

Any advice?  Or should I just try to find an EMS board and cache my data 
instead?  (Speaking of which, does anyone have a LIM EMS board for sale/trade? 
  Can't seem to find one of those either.)
-- 
Jim Leonard (trixter at oldskool.org)                    http://www.oldskool.org/
Want to help an ambitious games project?             http://www.mobygames.com/
Or check out some trippy MindCandy at             http://www.mindcandydvd.com/