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- THE JACKBOX
-
- MA BELL IS NOT THE ONLY ONE WITH STANDARDS! JUST ABOUT EVERY MANUFACTURER OF
- IC'S THAT GENERATE TOUCH TONES HAS ALSO GONE BY THE 16 KEY (8 TONE) STANDARD
- FOR TOUCH TONE PADS. AND IT IS EVEN EASIER TO CONVERT A TONE PAD THAT USES AN
- INTEGRATED CIRCUIT TO GENERATE THE TONES THAN CONVERTING A MA BELL PAD!
-
- IT WILL HELP IMMENSELY IF YOU HAVE THE SCHEMATIC FOR THE PAD IN QUESTION, OR
- AT LEAST THE PIN-OUT DIAGRAM OF THE CHIP BEING USED. PIN-OUTS CAN USUALLY BE
- OBTAINED FROM THE MANUFACTURER OR FROM AN ECG, SK, GE OR SIMILIAR
- SEMICONDUCTER HANDBOOK (PROVIDED THAT MANUFACTURER MAKES AN EQUIVALENT FOR
- THE CHIP IN YOUR PAD). I'LL USE THE RADIO SHACK CEX-4000 TONE PAD MODULE FOR
- AN EXAMPLE, EVEN THOUGH IT IS PROBABLY ALMOST THE LOUSIEST ONE YOU CAN BUY,
- IT IS FAIRLY TYPICAL ASILY AVAILABLE.
-
- TAKE A LOOK AT THE DIAGRAM OR THE PIN-OUT OF THE CHIP. YOU SHOULD SEE TWO
- GROUPS OF PINS, THE ROWS TONE PINS AND THE COLUMN TONE PINS. THESE WILL BE
- MARKED AS R1,R2,R3,R4 AND C1,C2,C3 (RADIO SHACK) OR OR X1,X2,X3 AND Y1,Y2,Y3
- ETC. ON OTHERS. AT ANY RATEU SHOULD BE ABLE TO DISTINGUISH WHICH THREE
- PINS CONTROL THE COLUMNS AND WHICH FOUR CONTROL THE ROWS. IF YOU'RE LUCKY,
- EACH GROUP OF ROWS AND COLUMNS WILL BE CONTIGUOUS. NOW LOOK AT THE COLUMN
- PINS, AND YOU'LL PROBABLY SEE AN EMPTY PIN RIGHT NEXT TO THEM. THIS IS THE
- COLUMN PIN FTHE 1633 HZ TONES. THESE CHIPS USUALLY ACHIEVE THEIR SWITCHING BY
- CONNECTING A ROW PIN WITH A COLUMN PIN (THAT WAY TQAN USE A0VERY SIMPLE
- KEYBOARD PAD, UNLIKE MA BELL'S COMPLICATED ONE). SO ALL YOU HAVE TO DO IS TAKE
- A SPDT SWITCH AND A FEW PIECES OF WIRE, CUT THE TRACE GOING TO THE COLUMN 3
- PIN OF THE CHIP, ATTACH A WIRE FROM THE CHIP SIDEOF THAT CUT TO ONE END OF THE
- SPDT SWITCH, A WIRE FROM THE OTHER SIDE OF THE CUT TO THE CENTER OF THE SPDT
- SWITCH, AND FINALLY, FROM THE REMAINING CONTACT ON THE SPDT SWITCH, HOOK A
- WIRE TO THE PREVIOUSLY IDENTIFIED PIN C4 (COLUMN 4). NOW YOU HAVE A "BANK
- SWITCHING ARRANGEMENT EXACTLY LIKE THE ONE DESCRIBED IN THE PREVIOUS BULLETIN
- FOR MODIFYING A MA BELL PAD.
-
- IF YOU CAN'T GET THE SCHEMATICS OR THE PIN OUTS FOR YOUR CHIP, DON'T DESPAIR.
- THERE IS STILL HOPE FOR YOU! YOU JUST HAVE TO TRACK THE CONNECTIONS GOING FROM
- THE PAD'S KEYS TO THE CHIP. CHANCES ARE YOU'LL FIND THAT EACH ROW HAS A COMMON
- TRACE, AND SO DOES EACH COLUMN (FOR THOSE NON-TECHNICAL FOLKS, A TRACE IS A
- CONNECTION ETCHED OUT ON A CIRCUIT BOARD). JUST FOLLOW THESE TO THE CHIP, AND
- MAKE YOUR OWN SCHEMATIC UP. NOW TAKE A LOOK FOR THAT EXTRA PIN--THERE SHOULD
- BE ONE FLOATING AROUND RIGHT NEXT TO THE COLUMN PINS. IT WILL BE NOT BE HOOKED
- UP TO ANYTHING ELSE, THAT IS, "HANGING FREE". DRILL A HOLE IN THE SIDE OF
- TONEPAD'S CASE, AND MOUNT YOUR SWITCH. RADIO SHACK SELLS A NICE MICROMINIATURE
- SWITCH THAT WORKS EXCELLENTLY! (ALMOST THE ONLY GOOD THING I CAN SAY ABOUT
- RADIO SHACK IN THIS ARTICLE)
-
- HAPPY PHREAKING...