Radio Shack TRS-80 Model 4 Technical Reference Manual

5
1.3 JUMPER OPTIONS
1.3.1 16K to 64K
1. Remove U77-U84
2. Move E5-E6 to E5-E4
Move E1-E2 to E2-E3
Move E12-E13 to E12-E11
3. Add E7-E8 and eight Tandy #8040665 ICs in
locations U77-U84.
4. Remove capacitors 068, 072, 076, 080, 084, 088,
092 and 096.
1.3.2 64K to 128K
1. Remove shunt at U72 and add IC Tandy
#8075468 in its place.
2. Add eight Tandy #8040665 ICs in locations U85-
U92.
1.3.3 Graphics Board
1. Remove E14-E15 (and screws near U65 and
U71).
2. Plug in Graphics Board
3. Replace mounting screws at U65 and U71.
1.3.4 E9-E10 are not used at this time

Radio Shack TRS-80 Model 4 Specifications

General

Brand	Radio Shack
Model	TRS-80 Model 4
Category	Desktop
Language	English