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Updated the readme, added a version number, and some todos, explaination about the state of banks and mappers

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Safiire 2015-02-22 17:49:45 -08:00
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README.md
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@ -1,4 +1,4 @@
# assembler6502 # assembler6502 0.3
An NES assembler for the 6502 microprocessor written in Ruby An NES assembler for the 6502 microprocessor written in Ruby
@ -9,9 +9,9 @@ An NES assembler for the 6502 microprocessor written in Ruby
It is good at knowing which addressing modes are and are not allowed for It is good at knowing which addressing modes are and are not allowed for
each instruction, and contains some examples of correct syntax. each instruction, and contains some examples of correct syntax.
Parsing is done by Regular Expression, because, well the language is This assembler does not understand banks or mappers yet, and so having
so regular, it actually took less time than anything else I've tried more than one PROG section does not quite work yet. That is next
to parse in the past, including Scheme using parsec. in line to be fixed.
It handles labels, and does a two pass assembly, first assembling It handles labels, and does a two pass assembly, first assembling
the byte codes, and then going back and filling in the proper addresses the byte codes, and then going back and filling in the proper addresses
@ -23,9 +23,13 @@ An NES assembler for the 6502 microprocessor written in Ruby
![Scrolling NES Demo](assembler_demo.png) ![Scrolling NES Demo](assembler_demo.png)
Some Todos: Some Todos:
- Allow lower case mnemonics in source code
- Understand how to deal with various mappers
- Understand how to create multiple banks
- Get an NSF file playing
- More unit tests for each instruction
- I may make this into a Rubygem - I may make this into a Rubygem
- Maybe I can put some better error messages. - Maybe I can put some better error messages.
- Should I also make a 6502 Emulator in Ruby?
Some new additions: Some new additions:
- Ported NES101 tutor to this assembler. - Ported NES101 tutor to this assembler.
@ -46,5 +50,8 @@ I decided that during the first pass of assembly, I should just initialize
an entire 65535 byte virtual memory images, and write the instructions to an entire 65535 byte virtual memory images, and write the instructions to
their correct places, and then after resolving symbols during the second pass, their correct places, and then after resolving symbols during the second pass,
I just clip out the Cartridge ROM area and iNES header at the end, works great I just clip out the Cartridge ROM area and iNES header at the end, works great
so far. so far. Now that I know I will need to support various mappers, I still may
use this method, but will need to create multiple 65535 memory segments and use
banking to distinguish them before finally writing out the resulting ROM in
the correct order.