On Tue, Jun 25, 2013 at 09:59:08PM +0200, Rhialto wrote: >I see that, as usual, the tape read/write part is very scarcely >commented :-) Even now, nobody understands what's happening apparently. FWIW, when I developed the C2N232 over 10 years ago, I tried to understand the Commodore tape routines using the sparsely commented disassembly in a hard copy of Mapping the Commodore 64, by Tim Arnot. In the end, I wrote the pulse stream receiver routine in the C2N232 and worked out the decoder. While doing that, I noticed a lot of jitter in the pulse widths produced by the Commodore 64 SAVE statement. I did not investigate if it is just the usual interrupt handling jitter (caused by having to complete the current instruction first). The Atmel AVR is much easier to program, and has nice input-capture and output-compare features, creating much cleaner signals in less code. :-) Marko Message was sent through the cbm-hackers mailing listReceived on 2013-06-26 19:00:06
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