Specifications

3000

UPM block diagram

Comparison with Archimedes expansion

cards

ARCHIMEDES J/O EXPANSION CARD

• The VIA is at the same address and clocked at the

same speed. Port A PA<0..2> is used to page

ROM. These are the same as the UPM when set for

2764/27128.

• The User port is the same (Port B). The VIA

interrupts go through a link, which is not normally

fitted.

• The MID1 section is not the same.

• The ADC and 1 MHz bus are not fitted to the UPM.

MIDI EXPANSION CARD

• The UART is the same (Signetics 2691), but is at a

different address (see below).

• The ROM page latch is not the same.

LA13

LAl2

offset address

MIDI Podule

UPM upgrade

&2000

&3000

Addresses of main system components

A3000 expansion