mon.txt

/////// PC-8801 ////////
///      'mon'      ///

Brief overview of usage for the native assembly language monitor. The ROM's
 machine language monitor has mini-assembler functionality, display for 
 octal and hex, ability to read/write to I/O ports, and disassemble.


][ BASIC Commands ][
====================

|  mon

Starts the machine language monitor


|  print hex$(peek(&HE7E9)*256+peek(&HE7E8))

Displays hex address of highmem


|  print hex$(peek(&HEB1C)*256+peek(&HEB1B))

Displays hex address of lowmem


|  clear ,&Hnnnn

Sets the base address of the ML program (usually clear ,&H9000)


][ MONITOR COMMANDS ][
======================

| ctrl+B

Return to BASIC


| STOP or ctrl+C

Return to previous line (e.g. typo)


| A

Assemble. Begin assembling, using Intel mnemonic, at the specified address.
 e.g. 
h] a9000 (enter)
9000 FF-(begin typing asm)

Z80        Equivalent
jr x		jmpr x
jr z,x		jrz x
jr nz,x		jrnz x
jr c,x		jrc x
jr nc,x		jrnc x
djnz x		djnz x


| B

Base. Change number base for display and input - bh is hex, bq is octal.
 e.g. 
h] bq
q]


| D

Dump memory. Shows hex representation of range provided. 
 e.g. 
h] d
0000 F3 31 A0 E1 C3 ...
 or 
h] d9000,9020
(lists memory from 9000h to 9020h)


| E

Edit memory. Opens a hex editor where you can enter values manually. Ctrl+C 
or ESC will return to mon.
 e.g. 
h] e9000
(opens hex editor at address 9000h)


| F

Fill memory. Fills from start address to target address with value N.
 e.g. 
h] f9000,9010,ff
h] d9000
9000 FF FF FF FF FF FF ...


| G

Go. Runs code starting at the specified address. Can optionally take 2 
breakpoint addresses as arguments.
 e.g.
h] g9000,9050,9080
 (Runs code from 9000h and stops either 9050h and 9080h)
h] g
 (Resets the machine - same as g0000)


| I

Input. Read a byte from the specified port address.


| L

Disassemble. Shows disassembly with mnemonic beginning at the specified 
address (takes an optional end address).
 e.g. 
h] l9000
9000  FF     RST 7   ...


| M

Move memory. Takes three arguments: start address of copy, end address of
copy, destination address.
 e.g. 
h] m9000,9100,a000
 (Copies 9000h-9100h to a000h-a100h.)


| O

Output. Outputs the given data byte to the specified port.
 e.g.
h] o10,ff
(Writes FFh to port 10)


| P

Printer switch. When enabled, any D, L and Ctrl+D command will be sent to 
the printer instead of the screen.


| R

Read tape. Only for tape access. 
 e.g.
h] rGAME
(Tries to load GAME from tape.)


| S

Set memory. Inline version of 'E' command. Use the spacebar to quickly tab 
forward to the next byte without modifying it, or ESC to cancel. Pressing 
return will commit to memory and return to mon.
 e.g. 
h] s9000
(Edit the byte at 9000h.)


| TM

Test memory. Valuable memtest tool if you have real hardware.


| V

Verify tape. Checks to see if what is present in memory is equivalent to what
 is on tape. Optionally takes filename argument, like R.
 e.g.
h] vGAME


| W

Write tape. Writes given filename to tape from given start and end memory 
addresses.
 e.g.
h] wGAME,9000,9100


| X

eXamine register. Optionally takes register name as argument (a, f, b, d,
 h, i, x, y, p (pc), s (sp)). No argument will print all registers.


| HELP key or Ctrl+A

Prints online help. In English, no less!


[With DISK BASIC:]

| Ctrl+D

Dump Disk. Prints disk data to screen.


| Ctrl+R

Read disk. Reads disk into memory.


| Ctrl+W

Write disk. Writes memory to disk.