mirror of
https://github.com/uffejakobsen/acme.git
synced 2024-12-24 16:29:23 +00:00
f1341c44fd
Finally disabled obsolete pseudo opcodes "!cbm", "!subzone" and "!realpc".
!pseudopc now *must* be used with a block in {} braces.
Added support for illegal opcode LXA #$00 (opcode 0xba).
git-svn-id: https://svn.code.sf.net/p/acme-crossass/code-0/trunk@26 4df02467-bbd4-4a76-a152-e7ce94205b78
120 lines
3.8 KiB
Plaintext
120 lines
3.8 KiB
Plaintext
|
|
|
|
ACME
|
|
|
|
...the ACME Crossassembler for Multiple Environments
|
|
|
|
--- compatibility problems ---
|
|
|
|
|
|
If you haven't used ACME before, you don't need to read this text.
|
|
It is only of use to people who upgraded from ACME 0.05 (or earlier)
|
|
to ACME 0.07 (or later).
|
|
|
|
You might encounter some slight incompatibilities: I have done a few
|
|
changes to ACME's workings.
|
|
Because backwards compatibility is the root of all evil (*g*), I did
|
|
not include any possibility to enforce the old behaviour. If one of
|
|
the following changes applies to your source files, assemble them with
|
|
this new release of ACME and then compare new and old output files.
|
|
|
|
Sorry for this inconvenience, but at least I think that there won't be
|
|
any further changes in the future.
|
|
|
|
|
|
----------------------------------------------------------------------
|
|
Section: Offset assembly / segment assembly
|
|
----------------------------------------------------------------------
|
|
|
|
Offset assembly is now done using a new pseudo opcode called
|
|
"!pseudopc". Have a look at "AllPOs.txt" for further information on
|
|
its syntax and usage.
|
|
The old way of just redefining the program counter by using more than
|
|
one "* = EXPRESSION" statements does something totally different now:
|
|
Whenever the program counter is redefined, ACME will actually change
|
|
its pointer into the output buffer, so you can write your code in
|
|
distinct segments. These segments can be given in any order. After
|
|
assembly, ACME stores everything from the lowest address used to the
|
|
highest address used. Have a look at "AllPOs.txt" for an example on
|
|
how to use this facility.
|
|
|
|
|
|
----------------------------------------------------------------------
|
|
Section: Argument order of MVP/MVN
|
|
----------------------------------------------------------------------
|
|
|
|
The syntax of the 65816 opcodes MVN and MVP is usually given as
|
|
|
|
MVN source_bank, destination_bank
|
|
|
|
All previous versions of ACME did it the other way round: First the
|
|
destination bank, then the source bank. This has been fixed, ACME now
|
|
uses the syntax given above.
|
|
|
|
|
|
----------------------------------------------------------------------
|
|
Section: Typecast
|
|
----------------------------------------------------------------------
|
|
|
|
You can use leading zeros to make ACME use a bigger addressing mode
|
|
than needed. Until now, this did not work when using labels. The
|
|
source code
|
|
|
|
label1 = $fa
|
|
label2 = $00fa
|
|
|
|
lda $fa
|
|
lda $00fa
|
|
lda label1
|
|
lda label2
|
|
|
|
was assembled to:
|
|
|
|
lda $fa
|
|
lda $00fa
|
|
lda $fa
|
|
lda $fa
|
|
|
|
Release 0.07 of ACME now correctly assembles the given source code to:
|
|
|
|
lda $fa
|
|
lda $00fa
|
|
lda $fa
|
|
lda $00fa
|
|
|
|
|
|
----------------------------------------------------------------------
|
|
Section: !endoffile
|
|
----------------------------------------------------------------------
|
|
|
|
Previous versions of ACME knew a pseudo opcode called "!end" that
|
|
marks the end of a source code file. Because the word "end" doesn't
|
|
actually specify *what* is about to end, I changed this to
|
|
"!endoffile". You can also use a short version, called "!eof". The old
|
|
PO "!end" no longer works.
|
|
|
|
|
|
----------------------------------------------------------------------
|
|
Section: Using the BIT command without parameters
|
|
----------------------------------------------------------------------
|
|
|
|
Release 0.07 of ACME will complain if you try to assemble BIT without
|
|
any parameter. Previous versions did just output the byte $2c - a
|
|
commonly known trick to mask the following 2-byte command on the 6502
|
|
processor. If you still want to do this, use
|
|
|
|
!src <6502/std.a> ; parse library file
|
|
|
|
to include some standard macros. Then you can use
|
|
|
|
+bit8 ; output $24 to mask following 1-byte command
|
|
|
|
and
|
|
|
|
+bit16 ; output $2c to mask following 2-byte command
|
|
|
|
respectively.
|
|
|
|
|
|
That's all. Again, sorry for the inconvenience...
|