DRAM chips

From BeebWiki
Revision as of 07:17, 22 February 2020 by Kazzie (Talk | contribs)

Jump to: navigation, search

Model A/B

The Model B uses a total of sixteen 4816 DRAM chips to give it 32K of RAM. These chips are arranged in two banks of eight chips, /CAS0 and /CAS1. Each chip provides one bit of storage for 16,536 (16K) memory locations. The Model A uses only one bank, /CAS1. The use of either or both memory banks is controlled by selection jumper S25.

Errors in a particular bit will correspond to a specific IC:

Model A/B
D0 D1 D2 D3 D4 D5 D6 D7
/CAS0 IC61 IC62 IC63 IC64 IC65 IC66 IC67 IC68
/CAS1 IC53 IC54 IC55 IC56 IC57 IC58 IC59 IC60