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@@ -22,6 +22,8 @@ When you fit a PAL device in it, make sure to align it to the bottom of the ZIF2
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**Pulling high pin 22 of the ZIF42 socket will turn on the transistor on the pod, which in turn will provide 5V to pin 22 of the ZIF24 socket**, pin 12 is hardwired to GND, and pin 24 to VCC.
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**Pulling high pin 22 of the ZIF42 socket will turn on the transistor on the pod, which in turn will provide 5V to pin 22 of the ZIF24 socket**, pin 12 is hardwired to GND, and pin 24 to VCC.
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+Some old PAL/GAL devices require more current than the switching via pin 22 can provide. In these cases, close JP1 to bypass the transistor and provide 5V directly.
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+
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#### Socket connections
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#### Socket connections
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This drawing shows how the pin on the ZIF24 sockets are wired to the pins on the dupico's ZIF42.
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This drawing shows how the pin on the ZIF24 sockets are wired to the pins on the dupico's ZIF42.
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@@ -31,7 +33,7 @@ This drawing shows how the pin on the ZIF24 sockets are wired to the pins on the
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1 ---> 1 U 24 <--- +5V
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1 ---> 1 U 24 <--- +5V
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2 ---> 2 23 <-- 41
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2 ---> 2 23 <-- 41
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3 ---> 3 22 <-- 40 --- 5V if ZIF42 pin 22 is HIGH
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3 ---> 3 22 <-- 40 --- 5V if ZIF42 pin 22 is HIGH
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- 4 ---> 4 21 <-- 39
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+ 4 ---> 4 21 <-- 39 or JP1 closed
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5 ---> 5 20 <-- 38
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5 ---> 5 20 <-- 38
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6 ---> 6 19 <-- 37
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6 ---> 6 19 <-- 37
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7 ---> 7 18 <-- 36
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7 ---> 7 18 <-- 36
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@@ -56,7 +58,7 @@ In its current form, the board is relatively simple build, using through-hole an
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| ----------------- | --- | ------------------------------ | -------------------------------------------------------- |
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| ----------------- | --- | ------------------------------ | -------------------------------------------------------- |
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| J1 | 2 | 21 pin 2.54mm headers | Use rounded pin headers to put less stress on dupico ZIF |
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| J1 | 2 | 21 pin 2.54mm headers | Use rounded pin headers to put less stress on dupico ZIF |
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| C1, C2 | 2 | 100nF / 1206 / ceramic | |
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| C1, C2 | 2 | 100nF / 1206 / ceramic | |
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-| JP1 | 1 | 2 pin 2.54mm header | Optional, bypasses the transistor |
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+| JP1 | 1 | 2 pin 2.54mm header | Bypasses the transistor and provides direct 5V |
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| Q1 | 1 | 2N3906 TO92 | |
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| Q1 | 1 | 2N3906 TO92 | |
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| J2 | 1 | narrow ZIF24 socket | Solder this AFTER the two J1 headers |
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| J2 | 1 | narrow ZIF24 socket | Solder this AFTER the two J1 headers |
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| U1 | 1 | 74CCT04 SOIC-14 | |
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| U1 | 1 | 74CCT04 SOIC-14 | |
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Fabio Battaglia