Make sure you have a bakcup copy of runpc186.exe in case this goes
wrong!!

type
ren runpc186.exe runpc186.bin
debug runpc186.bin
r
you will get a display which shows the contents of all the registers
followed by something like:

211D:0100 4D  DEC BP

The first 4 digits are important; add 1 to the first number - in
this case it becomes 311D

Now type S 311D:0000 03 ff 00 74 03
(replacing the 311D with the number you got in the previous step)
this will respond something like
311d:0545

To check that you've found the right bit type
u 311d:0545 (again, the numbers may be different)
the display should be something like:
311D:0545 83FF00  CMP  DI, +00
311D:0548 7403    JZ   054D

Note the number on the second line.

Type:
A 311D:0548
debug responds with
311D:0548
type NOP NOP and press Enter
debug responds with
311D:054A
Press Enter to get back to the - prompt then w Enter to write the file
Finally type q Enter to quit debug.

Type

ren runpc186.bin runpc186.exe

to get a version of runpc186 which doesn't check for an
RM machine.
