the10thwiz/cc65
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Completely disable/enable 80 column firmware.

Browse Source 
The //e 80 column firmware allows to switch between 80 and 40 clumns without clearing the screen. So far, I made that feature available via videomode(). However thinking about it once more, I don't see a C program making use of it. A C program rather benefits from the consistent behavior of videomode() always clearing the screen.
Apart from that, the (default) 40 column display and the 40 column display with 80 column firmware active, behave differently (CH vs. OURCH) which causes subtile issues. Those issues can be avoid altogether by simply always deactivating the 80 column firmware when switching from 80 column display to 40 column display.
Of course, those issues are also relevant, if the 40 column display with 80 column firmware is already active when the C program starts. However, I have reasons to believe that running the Apple II in that mode was/is very unpopular.
This commit is contained in:
Oliver Schmidt
2025-03-12 14:19:20 +01:00
parent c8eb6e2dd5
commit fd4c1e193d
2 changed files with 9 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/apple2enh.h
View File

@@ -82,8 +82,8 @@
#define CH_F10 0xB0
/* Video modes */
#define VIDEOMODE_40x24 0x0011
#define VIDEOMODE_80x24 0x0012
#define VIDEOMODE_40x24 0x15
#define VIDEOMODE_80x24 0x00
#define VIDEOMODE_40COL VIDEOMODE_40x24
#define VIDEOMODE_80COL VIDEOMODE_80x24