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Document interactive assembly mode

This commit is contained in:
Mike Naberezny 2012-01-15 13:04:27 -08:00
parent 6cdf95f4ef
commit c81eb0dcb6

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@ -34,18 +34,18 @@ Once the monitor has started, it will display a register dump and the
dot prompt. You can then enter commands for the monitor at this prompt.
Py65Mon uses commands that are very similar to those used by the monitor
included with the `VICE emulator <http://viceteam.org>`_ for Commodore
computers. You can get a list of available commands with ``help`` or
included with the `VICE emulator <http://viceteam.org>`_ for Commodore
computers. You can get a list of available commands with ``help`` or
help on a specific command with ``help command``.
Number Systems
--------------
When working with Py65Mon, you will frequently need to enter numbers, addresses,
and ranges of addresses. Almost all Py65 command support entering numbers in
and ranges of addresses. Almost all Py65 command support entering numbers in
binary, decimal, and hexadecimal.
Numbers can be entered with a prefix to specify the radix, e.g. ``$c000``
Numbers can be entered with a prefix to specify the radix, e.g. ``$c000``
instructs Py65Mon that the number ``c000`` is hexadecimal. The following
prefixes are supported:
@ -70,7 +70,7 @@ Some commands accept a range of memory addresses::
$ff84 a0 1c LDY #$1c
The syntax for a range is ``start:end``. Each of the two parts may have
a prefix to indicate the radix, or no prefix to use the default radix.
a prefix to indicate the radix, or no prefix to use the default radix.
Sometimes it is useful to have the starting and ending address in a range
be the same, such as when you want to inspect a single byte of memory. In
@ -81,7 +81,7 @@ Assigning Labels
Large assembly language programs may have hundreds of procedures. It is
difficult to remember the memory address of each procedure and the addresses
may change if the program is reassembled.
may change if the program is reassembled.
You can add a label for any memory address using the ``add_label`` command.
This label can then be used anywhere the address could be used::
@ -116,24 +116,33 @@ Command Reference
commands. If a label already exists at the address, it will be silently
overwritten.
.. describe:: assemble <address> <statement>
Assemble a statement at the address::
.. describe:: assemble <address> [<statement>]
Assemble a single statement at an address::
.assemble c000 lda $a0,x
$c000 b5 a0 LDA $a0,X
The assembler supports all legal NMOS 6502 opcodes and addressing modes. If
you have defined labels with ``add_label``, you may use those labels in the
address and the operand.
If no statement is given, interactive assembly mode will start::
.assemble c000
$c000
Enter a statement and it will be assembled at the current address. The
address will then be incremented and another statement may be entered.
Press Enter or Return without entering a statement to exit interactive
assembly mode.
If you have defined labels with add_label, you may use those labels in
the address and the operand.
.. describe:: cd <path>
Change the current working directory to the path specified::
.cd /path/to/my/files
/path/to/my/files
After changing the directory, the new working directory will be displayed.
The default working directory is the directory from which the monitor was
started.
@ -142,16 +151,16 @@ Command Reference
Display the number of cycles that the microprocessor has run
since it was last reset::
.cycles
12
12
.. describe:: delete_label <label>
Delete a label that was previously defined with ``add_label``::
.delete_label foo
If the label does not exist, the command will fail silently.
.. describe:: disassemble <address_range>
@ -184,18 +193,18 @@ Command Reference
.. describe:: goto <address>
Set the program counter to an address and resume execution::
.goto c000
.. describe:: help [<command>]
Display help for all commands or a single command. If no command is
given, a list of commands will be displayed::
.help
If a command is given, help for that comand is displayed::
.help disassemble
disassemble <address_range>
Disassemble instructions in the address range.
@ -203,7 +212,7 @@ Command Reference
.. describe:: load <filename> <address>
Load a binary file into memory starting at the address specified::
.load hello.bin c000
Wrote +29 bytes from $c000 to $c01c
@ -214,8 +223,8 @@ Command Reference
.load "say hello.bin" c000
Wrote +29 bytes from $c000 to $c01c
.. note::
.. note::
Unlike the VICE monitor, Py65Mon's ``load`` command does not expect
the first two bytes to be a Commodore-style load address. It will start
reading the file at byte 0, not byte 2.
@ -228,39 +237,39 @@ Command Reference
ff80: d8 a2 ff 9a a0 1c b9 bb ff 99 04 02 88 d0 f7 b9 d8 ff
ff92: f0 06 20 a6 e0 c8 d0 f5 20 a3 e0 90 fb 29 df
The contents will be wrapped to the terminal width specified by the
The contents will be wrapped to the terminal width specified by the
``width`` command.
.. describe:: pwd
Display the current working directory::
.pwd
/home/mnaberez
.. describe:: quit
Quit the monitor::
.quit
.. describe:: radix [<H|D|O|B>]
Display or set the default radix that is assumed for numbers that have no prefix.
Display or set the default radix that is assumed for numbers that have no prefix.
If no argument is given, the default radix is displayed::
.radix
Default radix is Hexadecimal
If an argument is given, the default radix will be changed::
.radix d
Default radix is Decimal
The default radix may be changed to Hexadecimal, Decimal, Octal, or Binary.
The default radix may be changed to Hexadecimal, Decimal, Octal, or Binary.
.. describe:: registers [<name=value>, <name=value>, ...>]
Display or change the registers of the microprocessor. If no arguments are
given, the registers are displayed::
@ -270,7 +279,7 @@ Command Reference
Registers can changed giving ``name=value``, separated by commas if
multiple registers are to be changed::
.registers a=02, x=04
<6502: A=02, X=04, Y=00, Flags=20, SP=ff, PC=0000>
@ -279,25 +288,25 @@ Command Reference
Reset the microprocessor to its default state. All memory will
also be cleared::
.reset
.. describe:: return
Continue execution and return to the monitor just before the next
Continue execution and return to the monitor just before the next
RTS or RTI is executed::
.return
.return
.. describe:: show_labels
Display labels that have been defined with ``add_label``::
.show_labels
ffd2: charout
.. describe:: step
Execute a single instruction at the program counter. After the instruction
executes, the next instruction is disassembled and printed::
@ -310,11 +319,11 @@ Command Reference
<6502: A=00, X=00, Y=00, Flags=34, SP=fc, PC=c000>
.
In the example above, the instruction at ``$C000`` executes and the monitor
prompt returns.
.. note::
In the example above, the instruction at ``$C000`` executes and the monitor
prompt returns.
.. note::
After the instruction executes, the disassembly of the **next** instruction
is printed. This allows you to see what will be executed on the next step.
@ -322,14 +331,14 @@ Command Reference
.. describe:: tilde
Display a number in the supported number systems::
.~ c000
+49152
$c000
140000
1100000000000000
The number will be displayed in this order: decimal, hexadecimal, octal,
The number will be displayed in this order: decimal, hexadecimal, octal,
and then binary.
.. describe:: version
@ -345,7 +354,7 @@ Command Reference
Display or set the terminal width. The width is used to wrap the output
of some commands like ``mem``. With no argument, the current width is
displayed::
.width
Terminal width is 78