6502/erc-c
1
0
Fork 0
mirror of https://github.com/pevans/erc-c.git synced 2024-08-21 00:29:00 +00:00
Code Issues Projects Releases Wiki Activity

Add address for reset vector, applesoft, powerup

Browse Source
This commit is contained in:
Peter Evans 2018-01-10 16:47:45 -06:00
parent aa486656b3
commit 538b5ddaa0
1 changed files with 24 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
include/apple2.h
View File

@ -11,6 +11,30 @@
*/
#define APPLE2_SYSFONT_SIZE 21558
/*
* The reset vector is the address where the apple will consult to
* figure out where control should go after a reset. Think of this as
* something like a pointer to a main() function in C. That is: where's
* the main function? Let's ask the reset vector!
*/
#define APPLE2_RESET_VECTOR 0x03F2
/*
* This is the address of the validity-check byte, aka the power-up
* byte. The Apple II will use this to see if the reset vector is valid.
*/
#define APPLE2_POWERUP_BYTE 0x03F4
/*
* I'm not _exactly_ clear on where the applesoft interpreter lives in
* ROM, after spending possibly too-much time researching how this
* works. My guess is I'm missing something that's obvious to others.
* $E000 seems to be the original spot that Integer BASIC was contained,
* and I'm going to guess Applesoft BASIC is in the same spot. Here's
* hoping!
*/
#define APPLE2_APPLESOFT_MAIN 0xE000
enum video_modes {
VIDEO_40COL_TEXT,
VIDEO_LORES,