[WriteLog] WL - Serial Cables & radio interfacing

[WA9ALS - John]

> 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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