penguin86/pato-z80-home-computer
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Started working on characters

Browse Source
This commit is contained in:
Daniele Verducci (ZenPenguin)
2021-01-22 08:58:11 +01:00
parent 17fdf97f75
commit 415300a2db
4 changed files with 154 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
pat80-io-devices/composite-pal-adapter/software/avr-assembly/main.asm
View File

@@ -23,7 +23,10 @@
; reserved registers
.def A = r0 ; accumulator
.def STATUS = r25 ; signal status (see STATUS TABLE)
.def POS_COARSE = Z ; coarse position (aligned to character column)
.def POS_COARSE_H = r31
.def POS_COARSE_L = r30
.def POS_FINE = r24 ; fine position (bit inside coarse-position-pointed byte)
; define constant
.equ SYNC_PIN = PC0 ; Sync pin (pin 22)
.equ DEBUG_PIN = PC1 ; DEBUG: Single vertical sync pulse to trigger oscilloscope (pin 23)