I got the meter talking to the computer. None of this appears to be documented in the US docs and nothing but the cable and diskette come along with the accessory with nothing in the doc files except for meter usage.
From the scopeview program setup, select: com port, 1200 baud, and M38XX, save settings but leave open.
In Device Manager open the LPT & Com port setup. Set the com port you're using to 1200, 7 bit, SPACE and 2 stop bits. Make sure the meter is on and then click on "turn on". If it initalizes, you'll see numbers. On my unit, there is no icon displayed on the meter screen when connected.
If you thought the meter is slow on these units, wait to you see the software. It's worthless for anything more then data logging. The "scope sweep" is a joke unless a one second sample plot is their idea of sweep. The analog bar graph has a few second delay when used in volt meter mode. Apparently, at some time, they quit distributing this Scopeview product by AGA software and replaced it with a Canadian BBT&T product called Metview. I can't find a copy on the net, just dead links, but the executable is M-3640-4295.EXE that apparently was the replacement software for XP for all the meters. I don't know if it's the one that's distributed with the Unisource meters on CD or what the connection between Unisource and Metex is. The products are the same and both names still seem to be in use. The MS9150/9160/9170 prefix has been changed to US91XX in the unisource models. There is either a usb port or just a serial/usb cable supplied with the Unisource models as the new software works with both a real serial port and a virtual one with a driver from what I gather.