i thought i’d start out with this hack while we’re in beta, since it was one of the first ones that really got me interested in the way phones worked and how many consumer electronics can be used for new and educational things. a “red box” was a device that would simulate coins being dropped in to a pay-phone, hence free phone calls for many people until the phone systems changed. the most popular device to modify was a radioshack tone dialer, a simple solder of a 6.5536 mhz crystal was all it took and you could “drop” 5, 10 and 25 cents at a time to make calls.
We really didn’t want to edit this because it’s a repost of the first Hackaday post ever, but [Phil Torrone] and [ladyada] dug out the old RadioShack pocket tone dialer, found a payphone (!), and tried it out:
RadioShack does not sell the pocket phone dialer anymore, but they do sell a DTMF chip (an NTE1690) that can do column D (the interesting bits that make all the phreakers happy).
We’ll probably end up reposting this one in another ten years.