Options
Help with McIntosh 861 DVD.
shr00m-dew
Posts: 394
Ok, so this is one of the most unnecessarily complex components I've had to deal with. Even Mac recommends doing RS232 to IR from their pre-amp (which I will probably do for control). I still need to process feedback from the player.
It does send some unsolicited feedback, but I need to send some query commands. I'm can't seem to figure out the checksums it's looking for. Here's from the PDF:
As you can see, the answers use the same checksum. Here's an unsolicited feedback with the BCCH & BCCL on the end to help make sense of it:
30=reply code
20=answer code
XX-XX=PC codes
3=end of text
33=BCCH
45=BCCL
If someone can help on the checksums I think I can get it. If someone has a full module I'll idol you forever!
Thanks,
Kevin D.
It does send some unsolicited feedback, but I need to send some query commands. I'm can't seem to figure out the checksums it's looking for. Here's from the PDF:
Commands : <STX> <CC> <PC0> <PC1> <PC2> <---------> <PCn> <ETX> <BCCH> <BCCL> STX (Start of TeXt) : 02h CC (Command Code) : Command code PC (Parameter Code) : Defined for each command ( contents and number of parameters ) ETX (End of TeXt) : 03h BCC (Block Check Character) : CC + PC0 + PC1 + PC2 + --------------- + PCn + ETX = XYh (Each of X and Y is 4 bit long ) X , Y=0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F BCCH ( high-level byte ) = X as converted to an ASCII code BCCL ( low-level byte ) = Y as converted to an ASCII code Answers : <STX> <RC> <AC> <PC0> <PC1> <PC2> <--------> <PCn> <ETX> <BCCH> <BCCL> STX (Start of TeXt) : 02h RC (Reply Code) : Reply code (=Command code) AC (Answer Code) : Answer code PC (Parameter Code) : Defined for each command ( contents and number of parameters ) ETX (End of TeXt) : 03h BCC (Block Check Character) : RC +AC + PC0 + PC1 + PC2 + ------------- + PCn + ETX = XYh (Each of X and Y is 4 bit long) X , Y=0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F BCCH ( high-level byte ) = X as converted to an ASCII code BCCL ( low-level byte ) = Y as converted to an ASCII code
As you can see, the answers use the same checksum. Here's an unsolicited feedback with the BCCH & BCCL on the end to help make sense of it:
2=start2,30,20,36,30,3E,3B,3B,30,30,31,30,30,30,30,30,30,30,30,30,30,30,30,3,33,45
30=reply code
20=answer code
XX-XX=PC codes
3=end of text
33=BCCH
45=BCCL
If someone can help on the checksums I think I can get it. If someone has a full module I'll idol you forever!
Thanks,
Kevin D.
0
Comments
Get a calculator out and put it into hex mode. Now add up all the numbers (starting with the reply code $30) except for the last two bytes and you should get $43E. Lopping off everything after 8 bits you get $3E. The high byte is $3 and the low byte is $E but those are supposed to be converted to ASCII. So the next to last byte in the response (BCCH) is a $33 which equals ASCII '3' and the last byte in the response (BCCL) is a $45 equals ASCII 'E'.
Does that help?
Thanks,
Kevin D.
Thanks again,
Kevin D.