I inherited an IBM PCjr some time ago and have recently begun playing with
trying to boot ELKS on it. This machine has an expansion module manufactured
by Racore which gives it 640K of RAM and a second 360K floppy drive. My
understanding was that this makes the machine roughly equivalent to an XT
(at least when running DOS). So far I have observed the following:
<> I need to get hold of a real 360K floppy drive for my main linux machine
since the FAQ said the 1.2MB drive I have can't really write properly to the
360K disks.
<> I have been able to compile the kernel decided to try using the 1.2MB
drive to dd it to one of the 360K floppies that came with the PCjr anyway,
and it seems to read the disk and boot partially.
<> There is a switch on the back of the Racore expansion module to put the
machine in either 'PC' or 'jr' mode.
<> With this switch in 'PC' mode, ELKS will start to load and after about
five or six dots past the 'ELKS Boot' prompt, the screen goes crazy with
different colored weird characters. The kernel appears to continue to load
and then the screen clears and a narrow flashing underscore cursor appears
in the upper left corner. After this there is no more activity or response
from keyboard input, and the cursor just sits there flashing.
<> With the switch in 'jr' mode, ELKS displays some more messages while
booting (although the screen still goes crazy). It gets all the way to the
point of saying:
...
Calibrating delay loop.. ok 0.16 BogoMips
PC/XT class machine, 8088 CPU
112K base.
ELKS kernel (57280 text + 10568 data + 50388 bss)
Kernel text at 1002:0000, data at 1DFE:0000
65468K of memory for user processes.
Killing with sig 13.
Generating sig 13.
panic: kernel restarted
apparant call stack:
(0) ret addr = E62 params = 0 0 0 0 0 0
(1) ret addr = 0 params = 0 0 0 0 0 0
(2) ret addr = 0 params = 0 0 0 0 0 0
(3) ret addr = 0 params = 0 0 0 0 0 0
(4) ret addr = 0 params = 0 0 0 0 0 0
(5) ret addr = 0 params = 0 0 0 0 0 0
(6) ret addr = 0 params = 0 0 0 0 0 0
(7) ret addr = 0 params = 0 0 0 0 0 0
After this, of course, there is nothing.
I am not much of a kernel hacker, but I do have some spare time (and a kinda
sick dream to someday run a really tiny linux HTTP server on a PCjr). I am
wondering if anyone on the list has any experience using ELKS on this
hardware or has some idea based on my limited results as to what might be
the best direction to start working in to get ELKS booting on this machine.
I have managed to get a root/boot disk system put together which boots and
runs vi, etc. on my other PC (a more recent pentium machine).
