Bus Arbiter

The Bus Arbiter is just there to keep things clean and to stop processors treading on each other's toes. There's a fair few pins I've no idea what the function is for. Suggestions are welcome!

PinNameDescription-PinNameDescription
1 GND Ground-51MCLKMaster Clock input
2 - Unknown-52 - Unknown
3 - Unknown-53 - Unknown
4 - Unknown-54 - Unknown
5 VA8 68K Address 8-55 - Unknown
6 VA9 68K Address 9-56 !SOUND YM-2612 !CS
7 VA10 68K Address 10-57 ZCLK Z80 clock
8 VA11 68K Address 11-58 !WRES Reset button input
9 VA12 68K Address 12-59 !ZRAM Z80 memory !CE
10 VA13 68K Address 13-60 !REF Unknown
11 VA14 68K Address 14-61 !M1 Z80 !M1
12 VA15 68K Address 15-62 !ZRES Z80 Reset
13 VA16 68K Address 16-63 !ZBR Z80 !BUSRQ
14 VA17 68K Address 17-64 !WAIT Z80 !WAIT
15 VA18 68K Address 18-65 !ZBAK Z80 !BUSAK
16 VA19 68K Address 19-66 !ZWR Z80 !WR
17 VA20 68K Address 20-67 !ZRD Z80 !RD
18 VA21 68K Address 21-68 !IREQ Z80 !IREQ
19 VA22 68K Address 22-69 !MREQ Z80 !MREQ
20 VA23 68K Address 23-70 !NMI Z80 !NMI
21 FC0 68K FC0-71 ZA0 Z80 Address 0
22 FC1 68K FC1-72 ZA7 Z80 Address 7
23 !VPA 68K !VPA-73 ZA8 Z80 Address 8
24 !VRES 68K !Reset-74 ZA9 Z80 Address 9
25 !HALT 68K !HALT-75 ZA10 Z80 Address 10
26 VD8 68K Data 8-76 ZA11 Z80 Address 11
27 - Unknown-77 - Unknown
28 - Unknown-78 - Unknown
29 - Unknown-79 - Unknown
30 VCLK 68K Clock-80 ZA12 Z80 Address 12
31 GND Ground-81 ZA13 Z80 Address 13
32 !TIME Unknown-82 ZA14 Z80 Address 14
33 !CAS0 I/O !CAS0-83 ZA15 Z80 Address 15
34 !DTAK 68K !DTAK-84 ZD00 Z80 Data 0
35 R/!W 68K R/!W-85 !FDWR Unknown
36 !LDS 68K !LDS-86 - Unknown
37 !VDS 68K !UDS-87 !ROM Unknown
38 !AS 68K !AS-88 !ASEL Unknown
39 !INTAK VDP !INTAK-89 !CAS2 Unknown
40 - Unknown-90 - Unknown
41 !VDPM Unknown-91 !RAS2 VDP !RAS2
42 !BG 68K !BG-92 !CE0 Unknown
43 !BGAK 68K !BGACK-93 !VTOV I/O !VTOV
44 !BR 68K !BR-94 !ZTOV I/O !ZTOV
45 !EOE 68K memory 2 !OE-95 !SRES I/O !SRES
46 IA14 Unknown-96 !IO I/O !IO
47 !NOE 68K memory 1 !OE-97 !M3 I/O !M3
48 EDCL HSCLK-98 !CART Cartridge presence
49 !OE0 x-99 - Unknown
50 !HSYNC !HSYNC from VDP-100 - Unknown

There's some supply pins that are marked as unknown, solely because I developed a headache whilst doing this!