Synthex CPU board information:

CPU: 6502, clocked 1MHz
0xfffa	NMI (MIDI)
0xfffc	RESET
0xfffe	IRQ

Memory map:
A14/A15 used to set signal XF2 on 0x0000 and 0xc000 address ranges
A12/A13 select the EPROMs. ROM1 (FM3) is highest, ROM4 is lowest. This gives the following addresses:

0xc000	ROM4 (not used)
0xd000	ROM3 (T41, A11 tied to GND)
0xe000	ROM2 (EM3)
0xf000	ROM1 (FM3)

EPROM address lines are swapped

CPU	EPROM
A0	1	A7
A1	23	A8
A2	2	A6
A3	22	A9
A4	3	A5
A5	4	A4
A6	5	A3
A7	19	A10
A8	6	A2
A9	7	A1
A10	8	A0
A11	18	A11 (/E, 21=A11))

EPROM data lines are swapped

CPU	EPROM
D0	17	D7
D1	16	D6
D2	9	D0
D3	11	D2
D4	13	D3
D5	14	D4
D6	10	D1
D7	15	D5
