A cassette interface for a Kansas City-style 6502 breadboard computer
It's been a long time since computer enthusiasts stored their programs and data on tape. But because floppy disk drives were expensive peripherals and hard drives were still far from the commodity they are today, cassette tapes have long been at the top of the mass data storage heap.
Celebrating this success by exploring tape-based data storage technology is the idea behind [Greg Strike's] Kansas City set-top box project, which he hopes to use with his [Ben Eater]-style 6502 computer. The video below explains the Kansas City Standard in detail and includes some interesting historical context that we really haven't delved into before. There are also some good technical details about the modulation scheme used by KCS, which [Greg] used to base his build on. After a failed attempt to use an LM567 tone decoding chip, he came across [matseng]'s KCSViewer project, which decodes KCS-encoded audio signals using only discrete components.
[Greg's] prototype has a comparator to convert sine waves to square waves, followed by a pair of monostable timers, each set to the high or low frequency defined in the KCS spec. A test cue created using Audacity - is there anything it can't do? — was successfully decoded, providing proof of concept for the first phase of the project. We look forward to the rest of the series, which will turn this into a real decoder, and probably add an encoder as well.
Hackaday podcast listeners may recall that we experimented with using KCS to hide certain data in an episode a few months ago.
It's been a long time since computer enthusiasts stored their programs and data on tape. But because floppy disk drives were expensive peripherals and hard drives were still far from the commodity they are today, cassette tapes have long been at the top of the mass data storage heap.
Celebrating this success by exploring tape-based data storage technology is the idea behind [Greg Strike's] Kansas City set-top box project, which he hopes to use with his [Ben Eater]-style 6502 computer. The video below explains the Kansas City Standard in detail and includes some interesting historical context that we really haven't delved into before. There are also some good technical details about the modulation scheme used by KCS, which [Greg] used to base his build on. After a failed attempt to use an LM567 tone decoding chip, he came across [matseng]'s KCSViewer project, which decodes KCS-encoded audio signals using only discrete components.
[Greg's] prototype has a comparator to convert sine waves to square waves, followed by a pair of monostable timers, each set to the high or low frequency defined in the KCS spec. A test cue created using Audacity - is there anything it can't do? — was successfully decoded, providing proof of concept for the first phase of the project. We look forward to the rest of the series, which will turn this into a real decoder, and probably add an encoder as well.
Hackaday podcast listeners may recall that we experimented with using KCS to hide certain data in an episode a few months ago.
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