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mirror of https://github.com/cc65/cc65.git synced 2024-11-19 06:31:31 +00:00
cc65/libsrc
Oliver Schmidt 5493c9e7c2
Don't empty the Receive Data Register on filling the Transmit Data Register
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`.
2022-09-08 17:11:30 +02:00
..
apple2 Don't empty the Receive Data Register on filling the Transmit Data Register 2022-09-08 17:11:30 +02:00
atari remove dangling spaces 2022-07-21 03:20:44 +02:00
atari2600
atari5200 remove dangling spaces 2022-07-21 03:20:44 +02:00
atari7800 Speed up the cursor a bit 2022-07-21 03:20:45 +02:00
atmos remove dangling spaces 2022-07-21 03:20:44 +02:00
c16 Exported the Commodore CHRIN and CHROUT Kernal functions, in the CBM libraries. 2021-03-03 17:39:53 -05:00
c64 detect number of RAM pages 2022-07-24 02:47:02 +02:00
c128 remove dangling spaces 2022-07-21 03:20:44 +02:00
cbm remove dangling spaces 2022-07-21 03:20:44 +02:00
cbm510 Exported the Commodore CHRIN and CHROUT Kernal functions, in the CBM libraries. 2021-03-03 17:39:53 -05:00
cbm610 remove dangling spaces 2022-07-21 03:20:44 +02:00
common Shorter isascii 2022-08-04 00:25:04 +02:00
conio remove dangling spaces 2022-07-21 03:20:44 +02:00
creativision remove dangling spaces 2022-07-21 03:20:44 +02:00
cx16 import RDTIM symbol instead of hard-wiring it here 2022-08-08 15:21:30 -05:00
dbg Removed an extra colon from libsrc/dbg/dbg/c. 2022-07-24 20:58:10 +08:00
em remove dangling spaces 2022-07-21 03:20:44 +02:00
gamate remove +x flag 2022-07-21 03:22:52 +02:00
geos-apple remove dangling spaces 2022-07-21 03:20:44 +02:00
geos-cbm remove dangling spaces 2022-07-21 03:20:44 +02:00
geos-common Revert "rename '_poserror' to '__poserror'" 2022-07-24 18:14:21 +02:00
joystick remove dangling spaces 2022-07-21 03:20:44 +02:00
lynx smarter manufacturer 2022-07-21 03:22:52 +02:00
mouse remove dangling spaces 2022-07-21 03:20:44 +02:00
nes remove dangling spaces 2022-07-21 03:20:44 +02:00
none
osic1p Fix switched meaning of '\n' and '\r' 2022-07-21 03:22:52 +02:00
pce remove dangling spaces 2022-07-21 03:20:44 +02:00
pet Exported the Commodore CHRIN and CHROUT Kernal functions, in the CBM libraries. 2021-03-03 17:39:53 -05:00
plus4 remove dangling spaces 2022-07-21 03:20:44 +02:00
runtime remove dangling spaces 2022-07-21 03:20:44 +02:00
serial change driver _install calls from taking "void*" to "const void*" 2021-05-16 22:57:28 +02:00
sim6502
supervision Syncronize the Supervision crt0.s with its ld65 config files. 2021-05-21 03:32:43 -04:00
sym1 remove dangling spaces 2022-07-21 03:20:44 +02:00
telestrat fix space 2022-07-21 03:22:52 +02:00
tgi Don't hide errors in error handling 2022-09-02 11:55:54 +02:00
vic20 Fixed cbm_k_readst() to work around a VIC-20 Kernal bug. 2021-03-25 15:22:18 -04:00
zlib zlib: Use correct (un)signedness of char in prototypes and functions. 2021-03-30 19:41:20 +02:00
Makefile build: allow empty prefix 2022-07-21 03:22:52 +02:00