//assert srdbl (we want to feed a jmp instruction)
    PORTJ&=~_BV(PORTJ_SRDBL_PIN_AL);

    //data bus output
    DDRA=0xff;

    //jmp opcode
    PORTA=0xc3;

    //assert busrq
    PORTG&=~_BV(PORTG_BUSRQ_PIN_AL);

    //release z80
    PORTG|=_BV(PORTG_RESET_PIN_AL);

    //wait for asserted busack
    while (PING & _BV(PORTG_BUSACK_PIN_AL))
      ;

    //low byte address
    PORTA=0x11;

    //release busrq
    PORTG|=_BV(PORTG_BUSRQ_PIN_AL);

    //assert busrq
    PORTG&=~_BV(PORTG_BUSRQ_PIN_AL);

    //wait for asserted busack
    while (PING & _BV(PORTG_BUSACK_PIN_AL))
      ;

    //high byte address
    PORTA=0x22;

    //release busrq
    PORTG|=_BV(PORTG_BUSRQ_PIN_AL);

    //assert busrq
    PORTG&=~_BV(PORTG_BUSRQ_PIN_AL);

    //wait for asserted busack
    while (PING & _BV(PORTG_BUSACK_PIN_AL))
      ;

    //data bus input
    DDRA=0;
    PORTA=0;

    //deassert srdbl
    PORTJ|=_BV(PORTJ_SRDBL_PIN_AL);

    //release busrq
    PORTG|=_BV(PORTG_BUSRQ_PIN_AL);