5 Jun
2013
5 Jun
'13
7:09 a.m.
On 06/05/2013 03:43 AM, Jim Brain wrote:
Good news, after dremeling the Dallase RTC and
performing minor
surgery to add an external coin cell battery, the 286/SLT is not
complaining at me on boot.
Double bonus, the 21.4MB HDD looks to be operational and boots to DOS
Triple bonus, the diag disk I made works, and cleaned up all of the
errors from not having a battery for so long.
Quadruple bonus, I've temporarily connected a 40GB 2.5" drive, fdisked
(to 528MB), formatted, and booted off said drive (regular 3.5
I've fixed a lot of the Dallas RTC cips with that failed coin cell.
When I did it I'd bring out the connections to leads
and use the larger 2016 or 2032.
" drives suck too much power and just overwhelmed
the little PSU in
the machine, even newer 160GB eco-models.)
So, my questions:
Is there any value in keeping the larger drive in the unit? I would
like to install Windows 3.1, DOS, some utils, etc., and I don't know
if all that will spill out of 21MB or not.
win3.1 is tiny and 21mb is large by that time and standard.
If the larger drive is in the unit, what would be
suggestions on
accessing the rest of the disk? I assume DOS will never see more than
528MB, since I had to tell the BIOS it was a COMPAQ drive type 42,
which is 528MB. I thought maybe Windows could see the rest of the
space once out of real mode, or maybe using the DOS from Win95 and
formatting FAT32 might help. I remember there being drive extenders
at some point, but I never used one (thankfully, all of my machines
understood LBA).
To access the larger disk you still hit the 1gb limits, then the 4gb
limits so you cant use it all
as the bios and drivers do not have enough LBA addressing bits. To get
to 1gb just create
multiple 528mb partitions.
The limits that machine suffers are the DOS/win3.1 FAT16 address limits
then the 1gb physical
address implementations limits.
The good news is by 286 standards a 500mb disk was effectively HUGE and few
people actually had that.
Allison
Thoughts appreciated. Permanently replacing the 21MB
drive means
doing some soldering on the little funky power cable used in the unit,
so I'd rather not mess with it unless there is some value to the
additional space.
Still, regardless, it lives, and research suggests the external KB
connector is XT, so I can use this to test an AT->XT converter project
I wanted to implement.
Jim