PT630 Operation Guide
Page 7 of 41
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COM Manager
The COM manager controls the communication link between the PT630 and the
host through a RS232 serial port.
LOADER
The function of the loader is identical to that of the MSDOS loader except for the
memory allocation/deallocation scheme being simplified. The loader's operations
are:
1. read .exe header
2. find enough memory for .exe
3. read binary into RAM
4. relocation based on RAM allocation
5. set up all registers
6. jump to the entry point
LCD Manager
The LCD manager handles the cursor positioning and graphic pattern display.
Two character pattern fonts are supported. PT630 can support both 6x8 font
(20
column by 8 lines)
and 8x16 font
(16 column by 4 line)
.
EXEC
The EXEC is the job scheduler. It manages top-level operation flow of the PT630
system. The EXEC program is analogous to the COMMAND.COM program in
MS DOS-based machines.
2.3 Operation
Flow
The EXEC program controls the PT630. When the portable terminal is powered up, EXEC performs
the power-on-test (POT). EXEC proceeds to verify if the PT630 should make a warm or cold
booting. A
warm boot
resets the system without clearing any RAM program or data files. Device
configurations preserve the same values as they had before the warm boot. On the other hand, a
cold
boot
will clear the RAM and initialize the PT630 to default values.
The PT630 is always testing its main and backup batteries. The LCD will display a warning message
when the test fails.
Power on Test
Test failure message
Main battery test
"WARNING MAIN BATTERY LOW"
Backup battery test
"WARNING LITHIUM BATTERY LOW"
When the main battery is low, a warning message will be displayed on the LCD when PT630 is
power on. For PT630, it can automatically detect battery status, a warning sign will be display on
battery icon on the upper side of LCD.
During the start-up process, EXEC also initializes the PT630 barcode scanner and RS232
communication port, and creates all dynamic data structures; e.g. keypad queue and COM buffer.
Once the initialization procedure has been completed, EXEC checks if a supervisor menu has been
