ferdimh@gmx.de wrote:
On 7 Dez., 23:04, Linards Ticmanis <ticma...@gmx.de> wrote:How will the PC be able to detect the length of a byte (8, 9 or 10 bits)? IMHO this is a must.I don't think so. There is no mechanism to detect that, and this is not needed. The Disk ][ doesn't detect it either.
Yes it does, if the reading code is keeping track of how long it takes for the high bit of the next nibble to be set. This led to several "bit stuffing" schemes for copy protection. Preservation of nibble length is necessary for such schemes.
It only has to be ensured that the data is shifted until the high bit is set. This is what the circuit does. For copying protected disks, it might be required. But I don't have any so I didn't care.
Ah. -michael NadaPong: Network game demo for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."