mirror of
https://github.com/michaelcmartin/Ophis.git
synced 2024-12-30 10:30:47 +00:00
43 lines
2.3 KiB
Plaintext
43 lines
2.3 KiB
Plaintext
This directory holds files likely to be of use to you in developing your own
|
|
programs. The contents of each file is summarized below.
|
|
|
|
|
|
c64_0.oph: A Commodore 64 equivalent to a modern compiler's "crt0.s" - it
|
|
contains a .PRG file header, a short BASIC program that launches
|
|
the machine language program, and a prologue and epilogue that
|
|
prepare memory for your use and then clean it up again when you
|
|
are done. Memory locations $02 through $8F on the zero page are
|
|
available for your use, and the program lives at the beginning
|
|
a contiguous block of RAM from $0800 through $CFFF. The BASIC
|
|
ROM is swapped out of memory (leaving $A000-$BFFF as RAM) for
|
|
the duration of your program. BASIC's working storage on the
|
|
zero page is backed up in the RAM underneath the KERNAL ROM
|
|
while your program runs.
|
|
|
|
c64kernal.oph: A collection of standard aliases for the KERNAL routines on the
|
|
Commodore 64. Names for these routines have been chosen to match
|
|
the Commodore 64 Programmer's Reference Guide. Additional useful
|
|
constants are defined for the character codes for color changes
|
|
and case-changing.
|
|
|
|
libbasic64.oph:A still-experimental set of macros and routines for exploiting
|
|
the software floating point routines in the Commodore 64
|
|
BASIC ROM.
|
|
|
|
c64header.oph: A much simpler Commodore 64 header that does nothing but jump
|
|
directly to your code. Useful for small programs or those that
|
|
intend to interface with BASIC.
|
|
|
|
vic20.oph: A simple header for the unexpanded VIC-20. Equivalent in
|
|
behavior to c64header.oph.
|
|
|
|
vic20x.oph: A simple header like the two above, but for expanded VIC-20.
|
|
|
|
nes.oph: A somewhat skeletal collection of aliases for the PPU registers
|
|
on the Nintendo Entertainment System. These names were chosen
|
|
to match the constant names given on the NESdev Wiki.
|
|
|
|
stella.oph: A collection of aliases for the registers of the Atari 2600.
|
|
These names were taken from the "Stella Programmer's Guide" and
|
|
are in wide use amongst developers and code analysts alike.
|