Acorn 32K Dynamic RAM Card

 Acorn 32K Dynamic RAM (front)

 This card came from a Busicomputers Prophet 3. the part no. is 200,010 issue 3.

 Acorn 32K DRAM card with 16K RAM (front)

 This card came from a System 5. The part no. is 200,010 issue 4.

Acorn 32K DRAM (back)

The Acorn 32K Dynamic RAM card is a Eurocard which can be used in a System or Atom computer.

The card provides up to 32K of RAM for a computer using Acorn's standard data bus. The ICs used are 5v 16k bit dynamic RAMs organised as 2 banks of 16K. Timing is generated in synchronisation with the CPU clock and the hardware refresh circuitry allows random access of the memory in any clock cycle. The RAM is organised into 4 sections each of which is 8K. These 4 sections can each be linked to begin at addresses 0, 2000, 4000, 6000, 8000, C000 and E000. In Acorn Systems 2, 3 and 4 the card will usually be used to provide 8K of program space at C000 to DFFF and 24K of text space at 2000 to 7FFF. A 16K card can then be used to fill the remaining space from 8000 to BFFF. Acorn Dynamic RAM cards can be mixed with static RAM cards and can be paged if required.