COMMON/README.md
2018-08-15 08:02:31 -04:00

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# COMMON
Advances some ideas using Steve Wozniaks 6502 SWEET16 interpreted byte-code language as inspiration. While the goal of SWEET16 was brevity, the goal of COMMON is functionality. The intent is to make a platform suitable for many commercial, scientific, and engineering applications.
For example:
* native type is equivalent to fixed-point decimal ±######.###
* easier support for banked memory
* easier support for higher language compilers
* arithmetic operations add, subtract, multiply, divide, and modulus
* inherent overflow/underflow detection
* all control branching is 16-bit relative, for easier relocatable code
* support for custom system/user functions, akin to INT in x86
Why 6502 and not, for example, x86?
* 6502 assembler is very easy and has a large archive of existing functions
* existing 6502 SWEET16 already has the “hard work” done
* interesting to see it run in newer versions of 6502 processors
* how do you think Bender does what he does? (or the Terminator!)
In progress:
* add all the instructions (see `common/common.h` for the list)
* a simple unit test suite to ensure each instruction is correct
The meat of the project:
* `common/common.h`: details of instructions
* `common/common.asm`: assembler code for the instructions
* `common/macros.h`: macros used to define the interpreted byte-code
* `common/page6.src`: sample source file using the macros
Auxiliary:
* `emulator/*`: 6502 emulator (borrowed Mike Chambers Fake6502 CPU emulator v1.1 ©2011)
* `xa-pre-process/*`: utility `xapp` to convert 32-bit fixed decimal quantities so that `xa` can use them
Right now, for testing purposes, the code builds everything into one file `system.obj` and runs the code in the last block loaded, in this case, the code corresponding to `page6.src`. Eventually will support decoupling of system and application files. Application files will be inherently relocatable.
To build and run:
make all
make run
The makefiles use `re2c`, `flex`, `bison`, `gcc`, `cpp`, and `xa`. Will eventually provide a `./configure`.