2 Jan
2007
2 Jan
'07
3:10 a.m.
Grant Stockly wrote:
On top of all this, I'm having a hard time
understanding the format.
This is a good line:
1 2 3 4 5 6 7 8 9 10 11 12 13
S1 13 0000 0D 76 00 F3 7E 18 F9 7E 03 3C 00 00 48 38 00 2C 7E
S1 means its a data record,
13 is the byte count,
0000 is the address,
and 7E is the checksum.
So what are the mystery bytes? How do you get 13 data bytes and still have
a place for all of the rest? 13 is supposed to include the checksum! The
checksum is the one's compliment of the sum of the all bytes except S1 and
the checksum itself.
FF-(13+0D+76+F3+7E+18+F9+7E+03+3C+48+38+2C)=7E
So 7E is the checksum. I want to know where all those bytes go! :(
Can't help you with the tape read problem although the speed issue as you
suggest sounds like a good guess, but as for the
byte count issue: it's 13 hex = 19 dec, which works out exactly for the line
you show when you include the address bytes (everything after the 13).
Lesson: you're up too late at night :) ...but then so am I (!) :/