6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2025-08-09 05:25:01 +00:00
Code Issues Projects Releases Wiki Activity

Fix Apple II/II+ text/lores hbl read addresses

Browse Source 
Closes #1181
This commit is contained in:
Ryan Schmidt
2023-10-25 01:44:48 -05:00
parent 98730f1f90
commit c206c7e2cb
1 changed files with 7 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
Machines/Apple/AppleII/Video.hpp
View File

@@ -178,6 +178,13 @@ template <class BusHandler, bool is_iie> class Video: public VideoBase {
if(mapped_row < 64) { if(mapped_row < 64) {
read_address += 128; read_address += 128;
} }
// On Apple II and II+ (not IIe or later) in text/lores mode (not hires), horizontal
// blanking bytes read from $1000 higher.
const GraphicsMode pixel_mode = graphics_mode(mapped_row);
if(!is_iie_ && ((pixel_mode == GraphicsMode::Text) || (pixel_mode == GraphicsMode::LowRes))) {
read_address += 0x1000;
}
} }
// Read the address and return the value. // Read the address and return the value.