26 Jul
2010
26 Jul
'10
12:03 p.m.
TBH, I don't know. I'm sure you're right,
though. I improvised a
solution involving a couple of instances of DRIVER.SYS and DRIVPARM or
something like that to persuade DOS that a 1.4MB drive was actually a
1.2MB drive, I think.
In which case you may have onl;y 15 valid sectors on each track (1.2M
format) not 18 (1.44M format). This could end up similar to the strange
disk image that I received...
Wel,
there's this PC for a start. It's a much-hacked PC/AT (8MHz version)
using the origianl motherboard and many of the original expansion cards.
The main changes are a 486 kldugeboard in the 286 socket (so I can run
linux), an earle IDE controller linked to a now-ancient drive, a 1.44M
3.5" floppy (as well as the origianl 1.2M one of course), a patch to the
ROM BIOS to modify the drive parameter tables (2 extra EPROMs and some
address deocnding logic fitted ot the mainboard, kludgewires all over
theplace), and various other piggy-back chip mods to correct timing
problems, add a drive-in-use LED, and so on.
Wow! *Impressed*
A decade and a half ago I was considering trying to do something much
like that with an original IBM PC if I could find one, using a 386sx board bodged into an XT-286. The idea being to try to
make the best,
fastest PC I could that was at heart an actual IBM PC, not a
compatible.
Mine started out as a challenge. As is well-known, I am forever moaning
about lack of real service data -- schematics and the like -- for
computer equipmetn. So, about 15 years ago I was set a challenge -- to
make a machine capable of running linux but which was 100% docuemtented
(not necessarily 'open' -- the scheamtics could be copyrighted, etc, but
they had to be avaialble). I had to be able to get full schematics and
source listings of all software involved (that included the ROM BIOS
needed to boot linux -- the linux sources took care of that requirement
for the OS).
I didn;t maanage it -- because I couldn't get a scheamtic of the hard
disk. But that was the only part I couldn't get. The guy swho set the
challenge acknowledged that I'd certainly met the spirit of the
requirements :-).
I'm impressed that you managed not only to get
such a thing running,
but to be using it still. For any kind of contemporary usage on the
21st-century Web, it must be incredibly slow.
It is slow. Very slow. And the video output is an origianl MDA text-only
card and monitor (I have a CGA card in there too, X doesn't support that
either, and I find text on the 5151 a lot easier to read than on any CGA
monitor I've tried (I have the original 5153 and an NEC TTL RGB monitor
that I modified to have RGBI inputs -- I did that before I amanged to
obtain a 5153). So not much hope of accessing most web sites. But it runs
gcc, it runs LaTeX, and things like that.
To be honest, on the few occasions that I need to look at graphical web
sites (mostly to read data sheets, technical manuials, etc) I go to an
internet cafe.
-tony