Sharp XE-A201 Service Manual page 11

CHAPTER 7. TEXT BLOCK FORMAT
1. BASIC FORMAT
1) ID-ENQ :
Terminal No. 000001-999999 (6 bytes)
EOT is set as dummy cahracters. (3 bytes)
2) ACK : 1 byte 06h
3) NAK : 1 byte 15h
4) EOT : 1 byte 04h
5) ENQ : 1 byte 05h
6) TEXT :
Data ASCII (max. 1000 bytes)
Block consecutive No.
Start code
Start code : This code may not be provided.
Null is impermissible.
End code : This code may not be provided.
Null or any same code as the start code is
not permissible.
When master reset is performed, the default is assumed:
Start code = 02h
End code = 0Dh
Block consecutive No. : This number starts with 30h and cycles
like this: 30h, 31h . 39h, 30h, 31h
(Ring counter system)
Check sum : 2 bytes hex number
Low-order 8-bit data of the complement of
2 for the sum of text data.
RAM data : Even number of data that is obtained by
dividing one byte of RAM data into high-
order 4 bits and low-order 4 bits and con-
verting them to ASCII codes shown in the
code conversion table.
10bytes
ENQ code (05h)
End code
Check sum
– 10 –
Code conversion table.
Print code (high-order or low-order 4 bits)
Bit image Hexadecimal
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Example
1 2
Memory image 02 5A
1
Line image 30h 32h
XE-A201UC
Line image
ASCII
0 30h
1 31h
2 32h
3 33h
4 34h
5 35h
6 36h
7 37h
8 38h
9 39h
A 41h
B 42h
C 43h
D 44h
E 45h
F 46h
3
F0
2 3
35h 41h 46h 30h
Transmission sequence