Q: How can I install more memory?
From Hardware
To install more memory, you need the Memory Extension Board. The board was initially offered with the 100B model. The board will accept 64Kbit or 256Kbit 80ns RAM chips in groups of nine. The memory extension board contains 3 banks of 9 chips. Each bank must be filled with all 64Kbit or 256Kbit chips, but the banks do not all have to be the same. The layout of the board is:
/---------------------------------------------------------------------------\
| XXXXX | XXXXX XXXXX EEEEEEE {{{3}}} {{{3}}} {{{2}}} {{{2}}} {{{1}}}|
| |
| XXXXX XXXXX SSSS XXXXX RRRRRR {{{3}}} {{{3}}} {{{2}}} {{{2}}} {{{1}}}|
| |
|XXXXXX | XXXXX | XXXXX RRRRRR {{{3}}} {{{3}}} {{{2}}} {{{2}}} {{{1}}}|
| | |
| XXXXX XXXXX XXXXX _______ XXXXX {{{3}}} {{{2}}} {{{1}}} {{{1}}}|
| |
| XXXXX | XXXXX |R XXXXXXX C| XXXXXXX {{{3}}} {{{2}}} {{{1}}} {{{1}}}|
| |C| |
| JJJJJJJJJJJJJJJJJJJJJJJJ |C | XXXXX {{{3}}} {{{2}}} {{{1}}} {{{1}}}|
\---------------------------------------------------------------------------/
The {{{#}}} indicates a socket in that respective bank. If a bank is filled with 256Kbit chips, the switch with that number must be turned on. If the bank is filled with 64Kbit chips, the switch with the same number as the bank must be turned off. If there are no memory chips in one bank, the switch for that bank must be turned off. Switch 4 is always turned on.
Current memory size can be found by pressing set-up (F3) on Rainbow 100Bs and 100+s.