Communication Protocol (Ver 0.1)
11
CAUTION – this function was designated for development and testing purposes. Improper use of this function may cause
erratic behaviour of the machine.
INSTRUCTION 11dec – READ EEPROM DATA
For sending to machine, DATA = EEPROM sub-address which is to be read.
When replying:- DATA = EEPROM sub-address; EXTENDED DATA = requested data.
The PC sends this instruction to the machine. The machine replies by sending back the data stored in this sub-address.
INSTRUCTION 12dec – WRITE I²C
DATA = I²C sub-address; EXTENDED DATA = data to be written to this sub-address. The PC sends I²C data (to the I²C
address which was last accessed via INSTRUCTION 13). The machine replies by sending the same data back to the PC.
CAUTION – this function was designated for development and testing purposes. Improper use of this function may cause
erratic behavior of the machine.
INSTRUCTION 13dec – READ I²C
For sending to machine, DATA = I²C address; EXTENDED DATA = sub-address. When replying:- DATA = sub-address;
EXTENDED DATA = data read.
The PC sends this instruction to the machine. The machine replies by sending back the data of this address and sub-address.
INSTRUCTION 14dec – READ VIDEO STANDARD
For sending to machine, set DATA = EXTENDED DATA = 0.
When replying:- DATA = 0; EXTENDED DATA = VIDEO STANDARD.
The PC sends this instruction to the machine. The machine replies by sending back the video standard, defined as follows:
0 = NTSC4.43
1 = NTSC
2 = PAL
3 = PAL-N
64dec (40hex)= Invalid or no input detected
Note that when the DIP-switches are set for a fixed standard, the 7408 will reply by sending the code for the fixed standard.
INSTRUCTION 16dec – ERROR
If the machine receives an invalid instruction, it replies by sending this error code.
INSTRUCTION 30dec – LOCK FRONT PANEL
DATA = 0: panel is unlocked.
DATA = 1: panel is locked.
EXTENDED DATA - set as 0.
- When the machine receives this instruction, it will lock or unlock the panel for control via the front-panel pushbutton
switches (RS-232 control is unaffected).
- When the user changes the lock status using the front-panel button, then this instruction is sent to the PC.
INSTRUCTION 31dec – REQUEST BAR
For sending DATA = EXTENDED DATA = 0
When replying EXTENDED DATA = 1, if Bar
INSTRUCTION 57dec – ENABLE “POWER-DOWN SAVE”
DATA = 0 disables power-down saving; DATA = 1 enables saving. EXTENDED DATA - set to 0.
The PC sends this instruction to the machine. The power-down option is enabled or disabled according to the value of DATA.
If the power-down option is enabled, then the machine will “remember” its state before being turned off, and revert to this
state when turned on again. Note that whenever the machine is turned on, the power-down save option is enabled.
INSTRUCTION 61dec – IDENTIFY MACHINE
For sending, DATA = 1 to request machine name; DATA = 3 to request software version number. EXTENDED DATA - set
to 0.
The PC sends this instruction to the machine. The machine relies as follows:
If the machine name is requested, the machine replies with DATA = 40 (hex), and EXTENDED DATA = 45 (hex).
If the software version is requested, the machine replies with DATA as the version number before the decimal point, and
EXTENDED DATA is the value following the decimal point. For example, for version 3.4, the machine replies with DATA =
03 (hex), and EXTENDED DATA = 04 (hex).
