TANDY/RADIO SHACK
4825 SX
|
Processor |
80486SX/80487SX/80486DX/80486DX2 |
|
Processor Speed |
25/33/50(internal)/66(internal)MHz |
|
Chip Set |
Unidentified |
|
Video Chip Set |
Unidentified |
|
Maximum Onboard Memory |
32MB |
|
Maximum Video Memory |
1MB |
|
Cache |
None |
|
BIOS |
Unidentified |
|
Dimensions |
394mm x 381mm |
|
I/O Options |
Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial ports (2), VGA feature connector, VGA port, riser slot |
|
NPU Options |
None |
|
CONNECTIONS | |||
|
Purpose |
Location |
Purpose |
Location |
|
VGA port |
CN1 |
IDE interface |
CN8 |
|
PS/2 mouse port |
CN2 |
External battery |
J1 |
|
Parallel port |
CN3 |
Speaker |
J2 |
|
Serial port 2 |
CN4 |
Reset switch |
J3 |
|
Serial port 1 |
CN5 |
Power LED |
J4 |
|
VGA feature connector |
CN6 |
Riser slot |
SL1 |
|
Floppy drive interface |
CN7 | ||
|
USER CONFIGURABLE SETTINGS | |||
|
Function |
Label |
Position | |
|
|
CMOS memory normal operation |
JP1 |
Open |
|
CMOS memory clear |
JP1 |
Closed | |
|
|
Monitor frequency select 31KHz |
SW1/5 |
Off |
|
Monitor frequency select 40KHz |
SW1/5 |
On | |
|
|
Monitor type select color |
SW2/3 |
Off |
|
Monitor type select monochrome |
SW2/3 |
On | |
|
DRAM CONFIGURATION | ||
|
Size |
Bank 0 |
Bank 1 |
|
4MB |
(4) 1M x 9 |
None |
|
5MB |
(4) 1M x 9 |
(4) 256K x 9 |
|
8MB |
(4) 1M x 9 |
(4) 1M x 9 |
|
16MB |
(4) 4M x 9 |
None |
|
20MB |
(4) 1M x 9 |
(4) 4M x 9 |
|
32MB |
(4) 4M x 9 |
(4) 4M x 9 |
|
VIDEO MEMORY CONFIGURATION | ||
|
Size |
Bank 0 |
Bank 1 |
|
512KB |
512KB |
None |
|
1MB |
512KB |
512KB |
|
Note: The location of banks 0 & 1 are unidentified. The size of the video memory chips are unidentified. | ||
|
VIDEO MEMORY SWITCH CONFIGURATION | |
|
Size |
SW1/6 |
|
512KB |
On |
|
1MB |
Off |
|
CPU TYPE SELECTION | ||
|
Type |
SW2/1 |
SW2/2 |
|
80486SX |
Off |
Off |
|
80487SX |
On |
Off |
|
80486DX |
Off |
Off |
|
80486DX2 |
Off |
Off |
|
VIDEO RESOLUTION SELECTION (800 X 600) | |||
|
Frequency |
SW1/1 |
SW1/2 | |
|
56Hz |
Off |
Off | |
|
60Hz |
Off |
On | |
|
72Hz |
On |
Off | |
|
56Hz |
On |
On | |
|
VIDEO RESOLUTION SELECTION (1024 X 768) | |||
|
Frequency |
SW1/3 |
SW1/4 | |
|
Interlaced |
Off |
Off | |
|
60HZ non-interlaced |
Off |
On | |
|
70HZ non-interlaced |
On |
Off | |
|
Interlaced |
On |
On | |
|
ON BOARD VIDEO SELECTION | |||
|
Setting |
SW1/7 |
SW1/8 | |
|
Enabled |
On |
Off | |
|
Disabled |
Off |
On | |