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[aprssig] Delayed packets (yet again)

Stephen H. Smith wa8lmf2 at aol.com
Fri Aug 25 20:15:24 UTC 2006

wes at kd4rdb.com wrote:
> This is the one I've got, and I've had problems programming tiny 
> tracks with it...
> http://www. 
> usbmax.com/U232-P9_DB-9_Serial__Adapter_High_Speed_230K_USB_SERIAL_RS-232_.cfm 
> <http://www.usbmax.com/U232-P9_DB-9_Serial__Adapter_High_Speed_230K_USB_SERIAL_RS-232_.cfm>

This is the MCT (Magic Control Technology) dongle based on the Prolific 
Technology USB<->Serial chip.   This is the cable sold by "Purple 
Computing"  at:


This chip and it's associated driver is notoriously fussy to configure 
on many systems.  

The Prolific chip is used in many USB-Serial converters and is built 
into some USB-interfaced GPS devices. [All GPS devices internally are 
serial -- in a "USB GPS" the conversion from serial to USB takes place 
inside the GPS case instead of in the middle of a cable.]  

A version of this same chip and driver are used in a 
USB-to-two-serial-port interface box sold by SIIG.  Picture of the 
device here:


The manual for this device in PDF format is here:


I have found that this version of the driver seems to be much less 
problematic on many other devices also based on the Prolific chip. After 
I installed the SIIG version of the driver, I was amazed to see that 
several other USB-based devices including a Holux USB-interfaced GPS 
mouse that had always been a flaky headace started working perfectly.  
You can download the driver from SIIG's website at:


Note that this download includes a utility "DDremover.exe" that should 
be run before installing, to remove any previous installations of the 
driver from your system. 

Stephen H. Smith    wa8lmf (at) aol.com
EchoLink Node:      14400    [Think bottom of the 2M band]
Home Page:          http://wa8lmf.com

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