/******************************************************************************
    BBC Model B

    MESS Driver By:

	Gordon Jefferyes
	mess_bbc@gjeffery.dircon.co.uk

******************************************************************************/

DRIVER_INIT( bbc );
DRIVER_INIT( bbcm );

MACHINE_INIT( bbca );
MACHINE_INIT( bbcb );
MACHINE_INIT( bbcb1770 );
MACHINE_INIT( bbcbopus );
MACHINE_INIT( bbcbp );
MACHINE_INIT( bbcm );


extern INTERRUPT_GEN( bbcb_keyscan );
extern INTERRUPT_GEN( bbcm_keyscan );

READ8_HANDLER ( BBC_NOP_00_r );
READ8_HANDLER ( BBC_NOP_FE_r );
READ8_HANDLER ( BBC_NOP_FF_r );


WRITE8_HANDLER ( memorya1_w );
WRITE8_HANDLER ( page_selecta_w );

WRITE8_HANDLER ( memoryb3_w );
WRITE8_HANDLER ( memoryb4_w );
WRITE8_HANDLER ( page_selectb_w );


WRITE8_HANDLER ( memorybp1_w );
/*READ8_HANDLER  ( memorybp2_r ); */
WRITE8_HANDLER ( memorybp2_w );
WRITE8_HANDLER ( memorybp4_w );
WRITE8_HANDLER ( memorybp4_128_w );
WRITE8_HANDLER ( memorybp6_128_w );
WRITE8_HANDLER ( page_selectbp_w );


WRITE8_HANDLER ( memorybm1_w );
/*READ8_HANDLER  ( memorybm2_r ); */
WRITE8_HANDLER ( memorybm2_w );
WRITE8_HANDLER ( memorybm4_w );
WRITE8_HANDLER ( memorybm5_w );
WRITE8_HANDLER ( memorybm7_w );
READ8_HANDLER  ( bbcm_r );
WRITE8_HANDLER ( bbcm_w );
READ8_HANDLER  ( bbcm_ACCCON_read );
WRITE8_HANDLER ( bbcm_ACCCON_write );


/*WRITE8_HANDLER ( bbc_bank4_w ); */

/* disc support */

DEVICE_LOAD ( bbcb_cart );
DEVICE_LOAD( bbc_floppy );

void check_disc_status(void);

READ8_HANDLER  ( bbc_disc_r );
WRITE8_HANDLER ( bbc_disc_w );

READ8_HANDLER  ( bbc_wd1770_read );
WRITE8_HANDLER ( bbc_wd1770_write );

READ8_HANDLER  ( bbc_opus_read );
WRITE8_HANDLER ( bbc_opus_write );


READ8_HANDLER  ( bbcm_wd1770l_read );
WRITE8_HANDLER ( bbcm_wd1770l_write );
READ8_HANDLER  ( bbcm_wd1770_read );
WRITE8_HANDLER ( bbcm_wd1770_write );


/* video code */

extern VIDEO_START( bbca );
extern VIDEO_START( bbcb );
extern VIDEO_START( bbcbp );
extern VIDEO_START( bbcm );
extern VIDEO_UPDATE( bbc );

extern unsigned char vidmem[0x10000];

void set_video_memory_lookups(int ramsize);
void bbc_frameclock(void);
void setscreenstart(int b4,int b5);
void bbcbp_setvideoshadow(int vdusel);

WRITE8_HANDLER ( videoULA_w );

WRITE8_HANDLER ( BBC_6845_w );
READ8_HANDLER ( BBC_6845_r );



/* tape support */

WRITE8_HANDLER ( BBC_6850_w );
READ8_HANDLER (BBC_6850_r);

WRITE8_HANDLER ( BBC_SerialULA_w );




