Hallo Marko, > > Could anybody explain me shortly two things: > > 1) Is the data send to the recorder the same as the real data to be saved? > > In principle yes, I think. I haven't played much with the tape, but I > think that -FLAG is an edge-sensitive input, while the processor line you > use to control WRITE is level-sensitive. > > > 2) How is the data translated to "music"? > > The data is stored as a square wave (okay, it is more sinusoidal, but an > op-amp and a cutter in the read circuitry of the datassette make it look > like a square wave again). I understand the part of translating a sinus to square; that is purely an electronic thing. Let's ask a simple question: 1) how are the bytes $FF and $00 put on tape? The thing I can add is that with the KIM a byte is split up in two nibbles. Then each nibble is translated to a character ranging from ??? to ???. Each bit of these bytes is translated in a two series of sinuswaves of two different frequencies. The length of each of the two blocks determines differs for bit 0 or 1. 0 = |AAA|BBBBBB| 1 = |AAAAAA|BBB| I cannot give more detailed info as I cannot get to it. If you look at the time the mail is generated (05.15), I writing during some pauses. Somebody messed up things at work and I was phoned out of bed to clear it up :( I can imagine that with the PET they skipped the splitting of the byte but translating a bit to a bit pattern still must nescesary. Groetjes, Ruud - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tcm.hut.fi.
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