Segment wrap of CS:IP is not supported for a single instruction
(i.e., instructions may not wrap around CS segment boundaries).

Segment wrap of effective address is not supported for a single
instruction (e.g., lds si,[bx] operand may not span DS boundary).

Segment wrap of rep insns is not supported.

Rep prefix instructions are not interruptible.

BIOS Disk I/O directly to video ram doesn't work.

To terminate pcm under 8086 control execute the following
(illegal) byte sequence: 0f 01 03.  Under DOS, you can make
a quit.com file to do this by feeding the following to DEBUG:

n quit.com
e 100
0f 01 03 cd 20
rcx
5
w
q

Fonts are in ./fonts.  You need to make your X-server aware
of them before running pcm.  If you are trying to use the tty
interface, ignore this and do a make tty.

Formatting floppies is currently a no-op, even for real
devices like /dev/rfd0c.  You need to format real floppies
beforehand.

----
todo:

fix parity flag calc. for shift/rotate insns
make video refresh transparent.
Make video bios calls write to video memory 
do hard disk emulation
network disk drives (ala Mach's mdos?)
do video attributes right
move more functionality into 8086 BIOS code

[eventually] dynamic translation to native code