Bulletins from the Pacific Packet Radio Society - page 077

2. Cut traces between U15 thru U18 pins 20 and U8 pins 15 to 12. Wire as follows:

A. U 15 pin 1 8 to U 8 pin 15.

B. U16 pin 18 to u8 pin 14.

C. U17 pin 18 to U8 pin 13.

D. U18 pin 18 to U8 pin 12.

3. Cut the trace hooking U15 thru U18 pin 19 to ground at some point between U18 and the ground bus. Hook the U15 to U18 pin 19 trace to U1 pin 23 (A10).

4. Wire U15 thru U18 pin 20 together and tie them to ground.

5. Cut the trace hooking U15 thru U18 pin 21 from the -5 volt bus between U1 8 and the -5 volt bus as shown.

6. Cut the traces at U8 pins 1,2, and 3.

Part 2, 2716 Wiring

5A. Hook the trace of U 15 thru U1 8 pin 21 to a +5 volt bus (Ul8 pin 24 is OK).

6A. Wire U8 pin 1 to U1 pin 24 (All). This can be done by hooking U8 pin 1 to the trace just cut from U8 pin 2, which is A11.

6B. Wire U8 pin 2 to U1 pin 25 (Al2). This can be done by hooking U8 pin 2 to the trace just cut from U8 pin 3, which is A12.

6C. Wire U8 pin 3 to U1 pin 26 (Al3). This could also be wired to ground, but wiring it to A13 will allow more EPROMs to be added later on.

This completes the modification. Plug in a 2716 with some software in it and try it out

Part 2, 2732 Wiring

5A. Wire the trace connecting U15 thru U18 together to U1 pin 24 (All).

6A. Wire U8 pin U1 to U1 pin 25 (Al2). A12 can be picked up from the trace just cut from U8 pin 3.

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