Mo6 - Running code at $b000-$efff

W_oo_d · **Inscription:** 04 Jan 2013, 13:18 **Messages:** 75

Hello

I have this MO6 program that works on emulators(DCMOTO and MESS) but not on the real machine:

I load a program to bank5 that will be used in the rom banking area (I have formatted the data to be used from $b000-$efff as the ram bank data will not be shown sequentially there)

The program that calls the routine at $b004 is:

Code:

            orcc   #$50    ;Disable IRQ and FIRQ

            lda #$52    ;%01010010 RAM commutation active
            sta $a7e7
      
            lda #$65   ;%01100101  write enable and ram enable -> bank 5 at $b000 
            sta $a7e6
            
            lda #$02
            sta $a7e5   ;bank 2 at $6000

            jmp $b004   

What might be wrong here? thanks

Prehisto

Sorry to give you an answer so late.

The #$52 value is not appropriate to activate the capability to switch RAM in direct mode. I think you should do instead :

Code:

            orcc   #$50    ;Disable IRQ and FIRQ
; Activate direct RAM switch mode
            lda $2081    ; Read read/write image of commutation register
            ora #$10     ; Activate direct RAM switch bit
            sta $2081    ; Update read/write image of commutation register
            sta $a7e7    ; Update commutation register
; Switch cartridge bank
            lda #$65   ;%01100101  write enable and ram enable -> bank 5 at $b000
            sta $a7e6
; Switch RAM bank
            lda #$02
            sta $a7e5   ;bank 2 at $6000

            jmp $b004   

W_oo_d · **Inscription:** 04 Jan 2013, 13:18 **Messages:** 75

Hi Prehisto thank you for that I will try it out asap.

Logicielsmoto.com

Mo6 - Running code at $b000-$efff

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