I've got this problem. (No, not that problem)
I might just have been working on this new WIMP-style OS when I hit a bit
of a problem with the FPC. In this hypothetical system, the individual
applications are time-sliced using the frame interrupt, which also
triggers key scanning etc.
These applications each have their own FP stack (like the ROM uses), and
can execute FP instructions using RST 28 commands like with the ROM. Now,
I implemented this by copying each ap's FPC stack onto the ROM's,
executing a copy of the instructions, and copying the resulting stack
contents back. My problem arose when a DPL application wanted to run a
background routine.
DPL-compiled aps use the FPC nearly all the time, meaning that the ROM is
nearly always paged in, and the mode 1 interrupts never reach Driver. So
no other programs get processor time, the pointer never seems to move and
so on. I thought about vectoring the interrupts back into Driver, but the
time-slice problem remains: I couldn't safely switch to another
application for fear of what was happening to the original FPC stack.
The only feasible solution was to write my own FPC. Help!
\\///
(o o)
+----------------ooO-(_)-Ooo----------------+
| Steve Taylor [EMAIL PROTECTED] |
| Pembroke College |
| Cambridge CB2 1RF |
+-------------------------------------------+
