# Spectravideo SVI318/328 Expansion Bus

(at the computer)

50 PIN MALE EDGE the computer.

Pin | Name | Dir | Description
--- | --- | --- | ---
1 | +5v |  | Power, 300mA
2 | /CNTRL2 |  | Game adapter control signal
3 | +12v |  | Power, 100mA
4 | -12v |  | Power, 50mA
5 | /CNTRL1 |  | Game adapter control signal
6 | /WAIT |  | Z80 WAIT
7 | /RST |  | Z80 RST
8 | CPU CLK |  | Buffered 3.58MHz system clock
9 | A15 |  | Buffered Address bus
10 | A14 |  | "
11 | A13 |  | "
12 | A12 |  | "
13 | A11 |  | "
14 | A10 |  | "
15 | A9 |  | "
16 | A8 |  | "
17 | A7 |  | "
18 | A6 |  | "
19 | A5 |  | "
20 | A4 |  | "
21 | A3 |  | "
22 | A2 |  | "
23 | A1 |  | "
24 | A0 |  | "
25 | /RFSH |  | RAM expansion refresh
26 | /EXCSR |  | Video-CPU write select
27 | /M1 |  | Z80 M1
28 | /EXCSW |  | CPU-Video write select
29 | /WR |  | Z80 WR
30 | /MREQ |  | Z80 MREQ
31 | /IORQ |  | Z80 IORQ
32 | /RD |  | Z80 RD
33 | D0 | I/O | Buffered Data Bus
34 | D1 | I/O | "
35 | D2 | I/O | "
36 | D3 | I/O | "
37 | D4 | I/O | "
38 | D5 | I/O | "
39 | D6 | I/O | "
40 | D7 | I/O | "
41 | CSOUND |  | Audio input signal
42 | /INT |  | Z80 INT
43 | /RAMDIS |  | Disable user RAM
44 | /ROMDIS |  | Disable basic ROM
45 | /BK32 |  | Enable bank 32 Memory (8000-ffff)
46 | /BK31 |  | Enable bank 31 Memory (0000-7FFF)
47 | /BK22 |  | Enable bank 22 Memory (8000-FFFF)
48 | /BK21 |  | Enable bank 21 Memory (0000-7FFF)
49 | GND | - | System Ground
50 | GND | - | System Ground

Contributor: Rob Gill

Source:
SVI 328 Mk II User Manual

Copyright © The Hardware Book Team 1996-2001.
May be copied and redistributed, partially or in whole, as appropriate.
Document last modified: 2001-06-07