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Extended image to 368x256

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Daniele Verducci su MatissePenguin 2021-02-14 19:08:45 +01:00
parent d71e5b65cf
commit 706dbe56e1
1 changed files with 7 additions and 7 deletions
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14
pat80-io-devices/composite-pal-adapter/software/avr-assembly/video_generator.asm
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@ -8,7 +8,7 @@
; This also displays byte's MSB pixel "for free", as the video pin is PD7 (last bit of PORTA).
; This module generates a Composite PAL monochrome signal with a resolution
; of 416x304 pixels of which only 376x232 pizels are visible (= 46x29 characters).
; of 416x304 pixels of which only 368x256 pizels are visible (= 46x29 characters).
; The signal is generated using 16-bit Timer1 and interrupts.
@ -43,8 +43,8 @@ on_tim1_ovf:
sbi PORTD, BUSY_PIN
; called by timer 1 two times per line (every 32 uS) during hsync, unless drawing picture.
inc STATUS
; if STATUS >= 176 then STATUS=0
cpi STATUS, 178 ; TODO: Added a seventh sync pulse at end of screen because at the first short sync after the image, the timer doesn't tick at the right time
; if STATUS >= 152 then STATUS=0
cpi STATUS, 152 ; TODO: Added a seventh sync pulse at end of screen because at the first short sync after the image, the timer doesn't tick at the right time
brlo switch_status
clr STATUS
; check status and decide what to do
@ -56,9 +56,9 @@ on_tim1_ovf:
cpi STATUS, 92
brlo empty_line ; 20-91: empty lines
breq start_draw_picture ; 92: draw picture
cpi STATUS, 164
brlo empty_line ; 93-165 = draw empty lines
jmp short_sync ; 166-177 = short sync
cpi STATUS, 140
brlo empty_line ; 93-139 = draw empty lines
jmp short_sync ; 140-151 = short sync
; reti is at end of all previous jumps
start_draw_picture:
@ -159,7 +159,7 @@ draw_picture:
ldi r26, 0xFF
; start 304 picture lines
ldi LINE_COUNTER, 232 ; line counter
ldi LINE_COUNTER, 256 ; line counter
h_picture_loop:
; ***************** DRAW FIRST LINE *********************