TODO

missing bdos functions:
	3 get reader input
	4 write punch output
	5 write listing output
	7 get i/o byte
	8 set i/o byte
	27 get alloc address
	28 write protect disk
	30 set file attributes

something wrong when winstall is run (but it works with BDOS)

provide simple key to exit simulator?

mount directories as drives in bdos emulator:  ./cpm --A /foo --B /bar ...

take yaze z80 simulator: it's probably more accurate (anyway it passes a
CPU tester).

improve putunix / getunix so that you can supply just a single file name

include a cpm disk manager utility: find one (maybe yaze)

- - -

something wrong when 'e' is given to ed.com (but it works with BDOS)
[fixed- only random access commands should write FCB bytes R0 - R2]

adventure doesn't work- it's seeking by modifying FCB directly
[fixed- now we keep file position in the FCB]

restore terminal on bdos errors
[fixed]

allow ESC alone to work
[fixed]

allow ^Z to work
[fixed]