7800 Expansion Module - Technicals








XM Technical Information:




cntrl1	$470
	d0 rof lo on
	d1 rof hi on
	d2 0=bios,1=top slot
	d3 1=hsc on
	d4 1=pokey on
	d5 1=bank0 on 4000-5fff
	d6 1=bank1 on 6000-7fff
	d7 1=ym2151 on

cntrl2	$478  - SALLY RAM bank 8K page multiplexer.
	d0-d3 sally ram page 0 a0-a3
	d4-d7 sally ram page 1 a0-a3

cntrl3	$47c  - MARIA RAM bank 8K page multiplexer.
	d0-d3 maria ram page 0 a0-a3
	d4-d7 maria ram page 1 a0-a3

cntrl4	$471
	d0 1=pia on
	d1-d3 flash bank lo a1-a3
	d4-d6 flash bank hi a1-a3
	d7 1=top slot lock

cntrl5 	$472
	d0 1=48k ram enable
	d1 1=ram we# disabled
	d2 1=bios enabled (in test mode)
	d3 1=POKEY enable/disable locked
	d4 1=HSC enable/disable locked - cannot disable after enable
	d5 1=PAL HSC enabled, 0=NTSC HSC enabled - cannot disable after enable




XMRAM Schematics:


(click image to enlarge)



Yamaha 2151 Development


X68000 emulators: (CLICK HERE)



Yamaha 2151 Datasheets (Adobe PDF)


Yamaha 2151 Users Manual (Adobe PDF)


Much more to come...