Commodore Plus 4 - Page 247

Machine-Language Monitor Commands 235
The monitor is asked to place the bytes $43, $59, $4E, $44, $49, $45, $20, and $4D
in memory starting at $2000. It does so and displays the resulting contents of
$2000 through $2007.
Examining Registers—The R Command
The R (Register) command is used to display the contents of the 6502 registers.
The syntax is as follows:
R
The monitor displays the contents of the 6502 registers. Listed will be the
program counter (PC), status register (SR), accumulator (A), X register (XR), Y
register (YR), and stack pointer (SP). The register dump is displayed on the
screen preceded by a semicolon. Since the semicolon is used to change register
contents, cursoring up to that line, changing the desired register(s), and entering a
RETURN is a good way of altering the contents of the registers.
Example: R
PC SR AC XR YR SP
; OOOOOO 00 00 00 F9
The monitor is asked to display the contents of the 6502 registers and does so.
Changing Registers—The ; Command
The ; (semicolon) command is used to change the contents of the 6502 registers.
The syntax is as follows:
; PC SR AC XR YR SP
The PC is the new program counter in hexadecimal.
The SR is the new status register in hexadecimal.
The AC is the new accumulator in hexadecimal.
The XR is the new X register in hexadecimal.
The YR is the new Y register in hexadecimal.
The SP is the new stack pointer in hexadecimal.
The monitor places the specified data bytes into the 6502 registers. This
command is normally executed following an R (Register) command by cursoring
back to its output line, changing the appropriate numbers, and entering a
RETURN. Only the register(s) to be changed and values for those displayed to
the left of them must be entered.