TANDY/RADIO SHACK
4820ST/T (250-5140)
Processor |
80486SX/80487SX/ODP486/ODPR486/80486DX/80486DX2 |
Processor Speed |
20/25/33/40/50(internal)/50/66(internal)MHz |
Chip Set |
Unidentified |
Video Chip Set |
None |
Maximum Onboard Memory |
64MB |
Maximum Video Memory |
None |
Cache |
None |
BIOS |
Unidentified |
Dimensions |
330mm x 218mm |
I/O Options |
Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial ports (2) |
NPU Options |
80487SX |
CONNECTIONS | |||
Purpose |
Location |
Purpose |
Location |
PS/2 mouse port |
CN1 |
IDE interface |
CN6 |
Serial port 1 |
CN2 |
Power indicator |
J1 |
Serial port 2 |
CN3 |
IDE interface LED |
J2 |
Parallel port |
CN4 |
External battery |
J3 |
Floppy drive interface |
CN5 |
Front panel connector |
J4 |
USER CONFIGURABLE SETTINGS | |||
Function |
Label |
Position | |
|
CMOS memory normal operation |
JP1 |
Open |
CMOS memory clear |
JP1 |
Closed | |
|
Monitor type select color |
SW1/3 |
On |
Monitor type select monochrome |
SW1/3 |
Off | |
|
Factory configured - do not alter |
SW1/4 |
Unidentified |
DRAM CONFIGURATION | ||||
Size |
Bank 0 |
Bank 1 |
Bank 2 |
Bank 3 |
1MB |
(4) 256K x 9 |
None |
None |
None |
2MB |
(4) 256K x 9 |
(4) 256K x 9 |
None |
None |
3MB |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 256K x 9 |
None |
4MB |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 256K x 9 |
4MB |
(4) 1M x 9 |
None |
None |
None |
5MB |
(4) 256K x 9 |
(4) 1M x 9 |
None |
None |
6MB |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 1M x 9 |
None |
8MB |
(4) 1M x 9 |
(4) 1M x 9 |
None |
None |
9MB |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 256K x 9 |
None |
10MB |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 1M x 9 |
(4) 1M x 9 |
12MB |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 1M x 9 |
None |
16MB |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 1M x 9 |
16MB |
(4) 4M x 9 |
None |
None |
None |
17MB |
(4) 256K x 9 |
(4) 4M x 9 |
None |
None |
18MB |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 4M x 9 |
None |
20MB |
(4) 1M x 9 |
(4) 4M x 9 |
None |
None |
24MB |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 4M x 9 |
None |
32MB |
(4) 4M x 9 |
(4) 4M x 9 |
None |
None |
33MB |
(4) 4M x 9 |
(4) 4M x 9 |
(4) 256K x 9 |
None |
34MB |
(4) 256K x 9 |
(4) 256K x 9 |
(4) 4M x 9 |
(4) 4M x 9 |
36MB |
(4) 4M x 9 |
(4) 4M x 9 |
(4) 1M x 9 |
None |
40MB |
(4) 1M x 9 |
(4) 1M x 9 |
(4) 4M x 9 |
(4) 4M x 9 |
48MB |
(4) 4M x 9 |
(4) 4M x 9 |
(4) 4M x 9 |
None |
64MB |
(4) 4M x 9 |
(4) 4M x 9 |
(4) 4M x 9 |
(4) 4M x 9 |
CPU TYPE SELECTION | |||
Type |
Socket |
SW1/1 |
SW1/2 |
80486SX |
CPU |
Off |
Off |
ODP486 |
CPU |
On |
On |
ODP486 |
NPU |
Off |
Off |
ODPR486 |
CPU |
On |
Off |
80487SX |
CPU |
On |
On |
80487SX |
NPU |
Off |
Off |
80486DX |
CPU |
On |
Off |
80486DX2 |
CPU |
On |
Off |