30 Aug
2005
30 Aug
'05
12:23 a.m.
I'm maxing out the machine for the sake of maxing out the machine.
The portable is a semi-rare beast; it's an XT in a wierd portable
case. I actually bought it as a machine to diagnose car problems
with via the DIACOM software, but I got rid of the car I was using it
on! now it's an experimentation box. I already did the 640K mod to
the mainboard, bought a 2MB EMS card, I have a 1.44MB floppy
controller that works as long as only the MFM disk is in the
system...it won't work with the IDE controller I have, OR the Seagate
ST02.
What do I have for software on it that I actually USE?
PC-DOS 2000
Wordperfect 5.1
Lotus 1-2-3 2.1
Quicken 6.0 for DOS
Windows 3.0
IBM PC Storyboard
All the Watcom TCP/IP tools I can find
Overland Data Tools for DOS (for backing the thing up to 9 track
tape, HAHA)
Oh...and I play a few games on it...yes. ;)
I do testing for the MS-DOS Turbo C port of Sarien with it, to make
sure it runs on 8088/8086.
So to say the machine is "lightly used" would be totally wrong. I
beat the silicon out of it.
On Aug 29, 2005, at 10:35 PM, Jim Leonard wrote:
Wolfe, Julian wrote:
1. Does anyone know a good solution for putting a
large drive in
an XT,
while still leaving it an XT?
IDE with "540MB" (actual capacity is less) drives or less, if you
can find an IDE card that works. I have two (different brands) but
sadly I haven't found time to try them yet in my model 5150. Only
other solution is SCSI, something I have had extremely unlucky
progress with (boards with BIOSes won't POST; boards that need
drivers don't have the damn drivers bundled with the board; etc.)
However, I believe my experience with 8-bit SCSI on XT is uncommon
compared with the other gentlemen here.
2. Should I leave the V20 in? I've heard it
has compatibility
issues with
some programs, but I'm not solid on my information.
The V20 can enable some ill-behaved programs to work as it
implements the "SHL register,immediate" 80186 opcode, and this
opcode is sometimes the *only* used opcode used in "286-only"
programs. I was able to run programs claiming they needed a 286 on
my AT&T PC 6300 (Olivetti M24 8086 clone) after I upgraded it to an
NEC V30.
HOWEVER, the V20 and V30 expand the prefetch queue from 4 bytes to
6 bytes (the source of their speedup) and this screws with timing-
sensitive programs such as games, copy-protected diskette copiers,
and turnkey stuff like robot controllers, etc. from the early 1980s.
I'm going to go out on a limb and assume that you're expanding your
convertable so that it can play most IBM PC games from the
1980s. :-) Based on my experience in that context, the V20 will
cause the following behavior compared to a factory original 8088:
- 88% of games will run just fine, unaffected by the V20
- 5% of games will run smoother/better due to the small speedup of
the V20
- 5% of games will run too fast to be enjoyable
- 2% of games will not run at all
Games are a good example to flush out this kind of behavior because
they were usually programmed as close to the hardware as possible
to achieve the best performance; also, many copy-protection schemes
are timing-based and may fail if the CPU speed is not what is
expected.
If I have incorrectly assumed your intentions, please let me know
as I'm dying with curiousity :-)
--
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/