[Jun/18/98]

PCB #1 (SK-7a) contains a 6502 CPU, a SN76477 sound chip
and 1x 2128 SRAM

filename	pcb	marked	type	     size
------------------------------------------------------
sk7_ic7.bin	IC7	ROM1	2732	     4Kx8
sk7_ic8.bin	IC8	ROM2	2732	     4Kx8
sk7_ic9.bin	IC9	ROM3	2732	     4Kx8
sk7_ic10.bin	IC10	ROM4	2732	     4Kx8
sk7_ic12.bin	IC12		2732	     4Kx8
sk7_ic14.bin	IC14	ROM5	2732	     4Kx8
sk7_ic15.bin	IC15	ROM6	2732	     4Kx8
		IC16	ROM7	empty
		IC17	ROM8	empty
sk7_ic51.bin	IC51		2716	     2Kx8
sk7_ic52.bin	IC52		2716	     2Kx8
sk7_ic53.bin	IC53		2716	     2Kx8

PCB #2 (SK-8a) contains a HD6845SP CRT controller,
6x 2114 DRAM, 2x 2128 SRAM and 1x 8pin DIP switch

filename        pcb     marked  type, comments
------------------------------------------------------
sk8_ic50.bin	IC50	ROM1	2732	     4Kx8
sk8_ic51.bin	IC51	ROM2	2732	     4Kx8
sk8_ic6.bin	IC6	B1	TBP18S030    32x8
sk8_ic7.bin	IC7	F	TBP18S030    32x8

The proms data lines are connected to resistors:
------------------------------------------------------
             1k         1k
IC6 bit0  --\/\/\---+--\/\/\--- IC7 bit0
	     470    |	470
IC6 bit1  --\/\/\---+--\/\/\--- IC7 bit1
	     220    |	220
IC6 bit2  --\/\/\---+--\/\/\--- IC7 bit2
		    |
	     470    |
      GND --\/\/\---+-------------------> (?) red

             1k         1k
IC6 bit3  --\/\/\---+--\/\/\--- IC7 bit3
	     470    |	470
IC6 bit4  --\/\/\---+--\/\/\--- IC7 bit4
	     220    |	220
IC6 bit5  --\/\/\---+--\/\/\--- IC7 bit5
		    |
	     470    |
      GND --\/\/\---+-------------------> (?) green

	     470	470
IC6 bit6  --\/\/\---+--\/\/\--- IC7 bit6
	     220    |	220
IC6 bit7  --\/\/\---+--\/\/\--- IC7 bit7
		    |
	     470    |
      GND --\/\/\---+-------------------> (?) blue



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[MAME]

Pioneer Balloon memory map (preliminary)

0000-03ff RAM		   IC13 cpu
0400-07ff Video RAM 1  IC67 video
0800-0bff Video RAM 2  ???? video
0c00-0fff Color RAM    IC68 (3 bits for VRAM 1 and 3 bits for VRAM 2)
1000-1fff RAM		   ???? Character generator
3000-3fff ROM 4/5	   IC12
4000-4fff ROM 1 	   IC07
5000-5fff ROM 2 	   IC08
6000-6fff ROM 3 	   IC09
7000-7fff ROM 4 	   IC10
8000-8fff ROM 5 	   IC14
9000-9fff ROM 6 	   IC15
read:
b104	  IN0
b105	  IN1
b106	  DSW
b107	  IN2

write
b000	  Sound Port 0
b001	  Sound Port 1
b100	  ????
b103	  bit 7 = flip screen
          bit 4-6 = music 2
          bit 3 = char bank selector
          bit 0-2 = background color
b106	  ????
b200	  y scroll register
b300	  x scroll register

Interrupts: VBlank causes an IRQ. Coin insertion causes a NMI.

-
