> 4.) Finally, the design architecture of the PC causes some
> strange results when you attempt to use more than two COM
> ports because of the sharing of hardware interrupts. Without
> getting too technical, be aware that often devices that use
> COM 1 and COM 3 may not work simultaneously because they share
> IRQ 4. Likewise, COM 2 and COM 4 devices share IRQ 3 and may
> not work simultaneously. To check this out, get all your
> Write Log devices working ONE AT A TIME. Once you achieve
> that, then try to use them simultaneously.
>
Excellent summary, Bob! I just want to comment about something that
works that surprised me at first. I have been able to use COM 2 (IRQ 3)
for PTT and FSK while using COM 4 (also IRQ 3) for IC-706MKIIG rig
control. Apparently this works because the PTT/FSK part doesn't have to
be ready to RECEIVE any data. I originally learned this tip from
N1RCT's web pages awhile back, and it might save someone an IRQ! 73
------------------------------------------------------------
WA9ALS - John
email: jfleming@shelbynet.net
homepage: http://www.qsl.net/wa9als
logbook: http://www.qsl.net/wa9als/search.htm
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