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