Canon AS-100M Field Service Manual page 19

8401 processor Is used for key code generation control and
has a 1KB ROM incorporated to control the timing of key code
generation, selected key code designation, and serial output.
The key matrix comprises of 13 sampling timings, KSO ' v KS12 and
key code KDO ' V KD7 of
can be discriminated.
matrix with eight keys of 104 appropriated for pointing device.
Concept of key code generation
Key -
pressing
Sampling
Key data are generated respectively when a key is pressed and
released, then, serially transferred to key input circuit.
CPU converts key data into internal codes.
exceeds 640ms, CPU automatically generates an internal code con­
tinuously as repeat mode.
KEY BOARD option
Pointing device ...... Carsol control for graphic.
1.2.5 5" FDD
The 5" FDD has two built-in MDD-220 units and is connected to
I/O controller via FDD controller, using a star chain.
8
bits, thus, 13 x
Pointing device is connected onto key
Confirmation of key release
when key code is same as
8
( D , key data IB
0
bit is " " are serially
transferred.
8
» 104 different keys
Confirmation of key release
when key code is same
th as (3) , key data IB
bit is is "l" are
serially transferred.
When key release time
1-13
©
n _
I
8
th
_