V. Sullivan
Peripheral Connector Modification
Peripheral connector #7 on the Euroapple had the VA signal attached to pin 39 for use as the line phase alternation signal by a PAL color adaptor board. To make this connector conform to the American Apple do the following.
1) Isolate pin 39 of the peripheral cone. #7
2) Jumper with #30 wire per. cone. #7 pin 39 to #6 pin 39
This modification is designed to reduce the amount of noise on the power lines in the RAM and ROM area.
1) If you look between chips C6 and C7 on the top of the board you will see a PTH. There is also a hole between chips D6 and D7,and E6 and E7. Using #24 solid wire connect jumpers from each of these three holes to the +5 Volt rail which runs on the bottom edge of the board near column 1 of the chips.
2) Connect 0.1 uF bypass capacitors between the following points.
FROM <------------> TO
C07-01 <-----------> C07-16
D07-01 <-----------> D07-16
ROM EO-12 <-------> ROM EO-24
ROM E8-12 <-------> ROM E8-24
ROM FO-12 <-------> ROM FO-24