Octagon 4010, Руководство пользователя, Страница: 47 / 118

Serial Ports – 37
COM1 AS RS–232 I/O
When you have completed developing your application and pro-
grammed the 4010, you can use COM1 as an RS–232 serial port for
connection to a printer, modem or other serial device. To access
COM1 you have two options:
1. Configure the 4010 for no console port by removing jumper
W3[1–2] and boot the system from SSD1 or floppy/hard drive
(not the BIOS drive). If you do not remove W3[1–2], the BIOS
sign on messages will be sent to your printer, modem or other
device connected to COM1.
2. Add a video card and monitor to your 4010 system.
Use a VTC–9F cable to connect the ports to the external serial
equipment. The pinout of the connector allows you to plug the
cable directly into a 9–pin PC serial connector.
DISABLING INTERRUPTS
The PC Bus does not allow shared interrupts on the bus. You can,
however, disable the COM1 and COM2 interrupts (IRQ4 and
IRQ3) to allow for other devices which use these interrupts. If
COM1 is the console, its interrupt (IRQ4) is in use. COM2 (IRQ3)
is not used by the BIOS. To disable interrupts for COM1, write a 0
to 3FC bit 3. To disable COM2 write a 0 to 2FC bit 3.
NOTE: You can also use different interrupts for COM3 (IRQ11)
and COM4 (IRQ10). IRQ9 and IRQ12 are also available. Refer to
Appendix B for more information on interrupts.
USING QUICKBASIC TO COMMUNICATE VIA COM1
Several programming languages including QuickBASIC V4.5
assume a video card is present, and for system speed reasons write
directly to the video hardware. This can be a problem since many
control applications require video output. The following discussion
is directed at QuickBASIC, but the principles (not accessing the
print routines which access the video memory directly) apply to
many languages. There are several ways to use COM1 from
QuickBASIC V4.5.
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