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...