Logitech 3D MOUSE & HEAD TRACKER Technical Reference Manual page 62

Chapter 6
50
The four-byte M+ format is shown in Table 6-8.
Figure 6-8. M+ Mouse Report Format
Name Bit6
Byte 1 1
Byte 2 0
Byte 3 0
Byte 4 0
• The fourth byte is transmitted only when one of the middle button
conditions is met.
Where in Table 6-8,
L = Left Button,
R = Right Button,
M = Middle Button,
X7...X0 = X movement since the last report is expressed as an 8
bit two's complement value (-128 to +127); positive
East.
Y7...Y0 = Y movement since the last report is expressed as an 8-
bit two's complement value (-128 to +127); positive
South.
DT4...DT0 = Device type; 5 bits interpreted as follows:
5...31 = Reserved for future use
In M+ format, data is transmitted in the form of seven-bit bytes. There
is one stop bit and no parity bit. Each report consists of three or four
bytes (depending on whether the middle button conditions are met).
Bit5 Bit4 Bit3
L R Y7
X5 X4 X3
Y5 Y4 Y3
M DT4 DT3
"1" = pressed
"1" = pressed
"1" = pressed
0 = Unknown
1 = Mouse
2 = Trackman(tm)
3 = Trackman Portable(tm)
4 = 3D Mouse
Bit2 Bit1 Bit0
Y6 X7 X6
X2 X1 X0
Y2 Y1 Y0
DT2 DT1 DT0