This file is incredibly old, and I really should prune it.



for the 8259 PIC:

  when you get an interrupt on one of the IRQ n lines, does the corresponding
  bit in the Interrupt Request Register get set regardless of the Interrupt
  Mask Register?


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- TODO -
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compile on as many machines as possible.

write document for developers outlining steps necessary to add devices.

add support for file descriptor events.  maybe can test with stdin.

print code out.  have a thorough look.

make a macro to check for events etc. so it can easily be called
  multiple times.

write LICENSE stuff.


*** remember to send manual EOI after interrupt routine ends.
  bx_outp(0x20, 0x20)  for EOI irq 0..7
  bx_outp(0xA0, 0x20)  both needed for irq 8..15

  and to enable IRQ 2 for cascade to slave PIC.
  bx_outp(0x21, bx_inp(0x21) & ~(1<<2));

bx_poke() ??? --> bx_access_physical() ???

complete initialization of BIOS data items for PIT, etc.

does INT 13h function 1 (Read diskette status) reset the status value to 0?

make new dependencies in Makefile for io_*.h files

change disk_param_table values.  modified them to see if
it would help the boot process.


95-04-11:
check video_x.c & io_mda.c for scan code correctness
write BIOS version/date/manufacture
rehash int16h handler to call int15 AX=9002h & AX=9102h
int09h: process meta keys
dosshell doesn't work?

95-04-16:
seperate out HGA io handlers into individual handler funtions

95-05-01:
does int13 funct 0x1 for floppies set return status to 0 after it reads it?

#ifdef'd int16 start & end offsets in BIOS var area

return keyboard hacks back to normal

bx_X_clear_screen(): should use X facility instead.

uncommented #if 0 around io_cmos functions 2-5.
