Subj : Beginner needs help with MSB/LSB and 7bit bytes
To   : comp.programming
From : Rich
Date : Thu Sep 29 2005 01:42 pm

Hey All,

I am trying to get my head around a particular concept. I want to write
an editor/librarian program for my midi guitar amplifier. I have a
description of the data pactets from the manufacturer, but I need some
help with how the MSB affects the value of the data. Below is a bit of
the explination from the manufacturer (This is midi sysex, which uses 7
bit bytes):

5E - Packed most significant bits for subsequent 7 bytes (x101 1110)

24 - Reverb Time (6.7) using MSB 1

56 - Reverb Dwell (4.0) using MSB 0

7F - Reverb Diffusion (9.9) using MSB 1

5D - Reverb Tone (8.7) using MSB 1

5D - Modulation FX Parameter 1 (8.7) using MSB 1

21 - Modulation FX Parameter 2 (6.6) using MSB 1

79 - Modulation FX Parameter 3 (5.2) using MSB 0

1D - Packed most significant bits for subsequent 7 bytes (x001 1101)

7F - Modulation FX Parameter 4 (5.4) using MSB 0

61 - Delay Time (510 ms) using MSB 0

I can grasp that the line saying "Packed most significant bits for
subsequent 7 bytes" means that from right to left, the bit is the MSB
for that byte, as they list next to byte with "using MSB 0"

But I cannot understand how the hex value 61, as in the last line can
get to a value of 510. I mean I can translate it to binary (x110 0001),
but I just can't see how they get 510 out of that.

remember, Im just a beginner, so I am sure I just don't understand. Any
help would be appreciated.

Thanks.

.