diff options
| author | Alexey 'Cluster' Avdyukhin <clusterrr@clusterrr.com> | 2020-09-27 15:39:57 +0300 |
|---|---|---|
| committer | Alexey 'Cluster' Avdyukhin <clusterrr@clusterrr.com> | 2020-09-27 15:39:57 +0300 |
| commit | 16b86f0194c4dd4e0a83a741d319c89850e35898 (patch) | |
| tree | 7a7293fe6e0d45532dca6122835e099c3ea52e12 /loader.asm | |
| parent | e02b7596d64dd9692567dfaccc7eeea1fbdfa958 (diff) | |
Banking, 512KB of CHR RAM support
Diffstat (limited to 'loader.asm')
| -rw-r--r-- | loader.asm | 45 |
1 files changed, 18 insertions, 27 deletions
@@ -41,31 +41,19 @@ load_all_chr_banks: ; how many 8KB parts left? lda #0 sta <CHR_BANK + sta <PRG_BANK + sta <COPY_SOURCE_ADDR + lda <LOADER_CHR_START_L + sta <PRG_SUPERBANK + lda <LOADER_CHR_START_H + sta <PRG_SUPERBANK+1 .loop lda <LOADER_CHR_LEFT beq .done dec <LOADER_CHR_LEFT - ; high address byte - lda <LOADER_CHR_START_H - sta $5000 - ; low address byte - lda <LOADER_CHR_START_L - sta $5001 - ; mask for 32KB banks - lda #$FE - sta $5002 - ; target CHR bank - lda <CHR_BANK - sta $5003 + jsr sync_banks ; source address - lda #$00 - sta <COPY_SOURCE_ADDR - ; source address overflow check lda <LOADER_CHR_START_S - bne .chr_not_null - lda #$80 - sta <LOADER_CHR_START_S -.chr_not_null: sta <COPY_SOURCE_ADDR+1 ; load 8KB of CHR jsr load_chr @@ -74,22 +62,25 @@ load_all_chr_banks: clc adc #$20 sta <LOADER_CHR_START_S + cmp #$C0 ; is it overflowed? - bcc .chr_s_not_inc - ; yes, increase source address for two banks - lda <LOADER_CHR_START_L + bne .chr_s_not_inc + ; yes + lda #$80 + sta <LOADER_CHR_START_S + lda <PRG_SUPERBANK clc - adc #2 - sta <LOADER_CHR_START_L - lda <LOADER_CHR_START_H + adc #1 + sta <PRG_SUPERBANK + lda <PRG_SUPERBANK+1 adc #0 - sta <LOADER_CHR_START_H + sta <PRG_SUPERBANK+1 .chr_s_not_inc: ; increase target CHR bank number inc <CHR_BANK jmp .loop .done: - jsr flash_set_superbank_zero + jsr banking_init rts ; loading tiles to CHR RAM |