Specifications

University of Hertfordshire

5.1.2 I/O Base Address and Wait State Setting

The I/O ports base address and the numbers of wait states are selectable by the 8 position DIP

switch SW1. This card takes 16 addresses of I/O port following the base address. The digital output

port takes the addresses of BASE+0 and BASE+1 and the IEEE-488 interface takes the addresses

from BASE+8 to BASE+15. The default address of the IEEE-488 interface is hex 2B8.

The switch settings for various base addresses and wait states are illustrated as below:

Note: ON = 0, 0FF = 1

1 to 8 are switch positions

W0, W1 correspond to wait state

A4 to A8 correspond to address lines of the PC bus

* means factory setting

Table 5.1 Setting IO Address (SW1)

The last two bits of SW1 are wait state(s),

Table 5.2 Setting Wait States (SW1)