Fix off by 1 error

2023-10-25 20:39:55 -07:00
parent 6fabd23125
commit 6f36d2fcc4
3 changed files with 176 additions and 171 deletions
--- a/sw/bios/boot2.s
+++ b/sw/bios/boot2.s
@@ -158,12 +158,15 @@ _start:

        sec
        sbc #$02                ; don't handle carry, assume low byte is not 0 or 1
+        clc
+        sta tmp1
        ldx data_start + 1      ; load x as high data start
        phx
        ldx sectors_per_cluster ; multiply cluster num (minus 2) by sectors_per_cluster
-@4:     adc tmp1
+        lda #$00
+@8:     adc tmp1
        dex
-        bne @4
+        bne @8
        plx
        clc
        adc data_start          ; add that to low data start
--- a/sw/bios/bootloader.s
+++ b/sw/bios/bootloader.s
@@ -118,10 +118,12 @@ _main:
        
        sec
        sbc #$02                ; don't handle carry, assume low byte is not 0 or 1
+        clc
        sta tmp1
        ldx data_start + 1      ; load x as high data start
        phx
        ldx sectors_per_cluster ; multiply cluster num (minus 2) by sectors_per_cluster
+        lda #$00
@4:     adc tmp1
        dex
        bne @4