Editing Acorn Archimedes A305 (section)

== Expansion Options ==

The A305 provided identical expansion capabilities to other Archimedes models, though memory limitations affected the practical use of some peripherals.

=== Podule Slots ===

Four 96-pin expansion slots accepted the same range of podule cards as the A310:
* '''SCSI interfaces''' - Adding hard drives often required memory upgrade
* '''Network cards''' - Econet and Ethernet adapters
* '''Video digitizers''' - Required 1 MB for practical use
* '''MIDI interfaces''' - Worked acceptably with 512 KB
* '''ROM podules''' - Ideal for A305 due to no RAM requirement

The backplane operated at full 8 MHz speed with automatic speed detection for slower peripherals. Each slot provided standard power rails, though the linear PSU limited total expansion capacity.

=== Internal Upgrades ===

Beyond memory expansion, A305 owners could install:
* '''ARM3 processor upgrade''' - 25 MHz ARM3 with 4 KB cache
* '''MEMC1a upgrade''' - Required for 4 MB RAM support
* '''RISC OS carrier board''' - Upgraded ROM capacity to 2 MB
* '''Econet module''' - Internal networking interface
* '''Battery backup - For CMOS settings retention'''

The ARM3 upgrade proved particularly popular with A305 owners, as the 4 KB cache partially compensated for limited main memory by reducing memory bandwidth requirements.