TANDY/RADIO SHACK
MEMORY EXPANSION BOARD (250-4030)
Card Type |
Memory |
Maximum Onboard Memory |
2MB DRAM |
Data Bus |
16-bit ISA |
USER CONFIGURABLE SETTINGS | |||
Setting |
Label |
Position | |
» |
Factory configured - do not alter |
S1/1 |
Off |
» |
Factory configured - do not alter |
S1/7 |
N/A |
» |
Memory in Bank 1 enabled |
S1/8 |
Off |
Memory in Bank 1 disabled |
S1/8 |
On | |
Note:Bank 1 should be disabled only if the board number is set to 1. |
DRAM CONFIGURATION | ||||
Size |
Bank 0 |
Bank 1 |
Bank 2 |
Bank 3 |
512KB |
(18) 256K x 1 |
None |
None |
None |
1MB |
(18) 256K x 1 |
(18) 256K x 1 |
None |
None |
1.5MB |
(18) 256K x 1 |
(18) 256K x 1 |
(18) 256K x 1 |
None |
2MB |
(18) 256K x 1 |
(18) 256K x 1 |
(18) 256K x 1 |
(18) 256K x 1 |
Note:The exact location of each bank is unidentified. |
DRAM JUMPER SELECTION | |||
Size |
S1/5 |
S1/6 | |
512KB |
On |
On | |
» |
1MB |
Off |
On |
1.5MB |
On |
Off | |
2MB |
Off |
Off |
BOARD NUMBER SELECTION | |||||
Number |
Address |
S1/2 |
S1/3 |
S1/4 | |
» |
1 |
100000h |
On |
On |
On |
2 |
300000h |
Off |
On |
On | |
3 |
500000h |
On |
Off |
On | |
4 |
700000h |
Off |
Off |
On | |
5 |
900000h |
On |
On |
Off | |
6 |
B00000h |
Off |
On |
Off | |
7 |
D00000h |
On |
Off |
Off |