Reverse-engineering QT150 drivers

[atax1a]

Hi! I'm new here and have spent a bit of time playing with MacNosy to try and reverse-engineer the QT 150 drivers. However, we're hitting some roadblocks - the drivers seem to use GeoPort calls, which aren't very well documented, and also the drivers seem to work by way of Foreign File Access, which also has very little documentation. Steve Jasik of MacNosy connected us with Steve Sisak, who is versed in serial drivers, but I'm also reaching out here to see if anyone else has pointers.

 

[aladds]

If it were me I’d be sniffing the serial bus, but I’m more of a hardware person
RS422 is multi-drop so you can just hook the lines into a USB adaptor (or likely two, since you want both directions). Using a logic analyser would likely require a line receiver so might be more complicated. Don’t connect an extra termination resistor!

Then you can go through the different functions from the Mac side, watch what gets sent over serial and use that information to make your new driver.

In fact, it has windows drivers doesn’t it, so it’s probably RS232 compatible which would make this even easier!