mirror of
https://github.com/cc65/cc65.git
synced 2024-12-27 00:29:31 +00:00
5493c9e7c2
The Receive Data Register and the Transmit Data Register share share a single address. Accessing that address with STA abs,X in order to fill the Transmit Data Register causes a 6502 false read which causes the Receive Data Register to be emptied. The simplest way to work around that issue - which I chose here - is to move the base address for all ACIA accesses from page $C0 to page $BF. However, that adds an additional cycle to all read accesses. An alternative approach would be to only modify the single line `sta ACIA_DATA,x`. |
||
---|---|---|
.. | ||
apple2 | ||
atari | ||
atari2600 | ||
atari5200 | ||
atari7800 | ||
atmos | ||
c16 | ||
c64 | ||
c128 | ||
cbm | ||
cbm510 | ||
cbm610 | ||
common | ||
conio | ||
creativision | ||
cx16 | ||
dbg | ||
em | ||
gamate | ||
geos-apple | ||
geos-cbm | ||
geos-common | ||
joystick | ||
lynx | ||
mouse | ||
nes | ||
none | ||
osic1p | ||
pce | ||
pet | ||
plus4 | ||
runtime | ||
serial | ||
sim6502 | ||
supervision | ||
sym1 | ||
telestrat | ||
tgi | ||
vic20 | ||
zlib | ||
Makefile |