My Computer Has No Parallel or Serial Ports

[AaronNewman]

Hi

I wanted to share my successful experience in this regard. I wanted to run DirectRT on a MacBook Pro (Intel CPU-based Apple laptop, using Windows XP installed under BootCamp), and send TTL codes to my EEG system. Since the MBP (like all Apples) has no parallel port, this was a problem. The MBP does, however, have an ExpressCard34 port, which is on the PCI bus (i.e., the same bus you'd plug a parallel port card into on a desktop computer). On the web, I found an ExpressCard-to-parallel adapter. There are several out there; I ordered this one, based on the fact that they would ship to Canada and had a customer-friendly return policy if the card didn't work for my application.

Installing the card was simple, just a matter of installing the driver off the included CD and then pluggin the card in. The trick to getting it working was finding out what its hardware address was. Unlike a built-in parallel port, this one does not show up in DirectRT's TTL I/Otest application. So, as described in DirectRT's documentation, I went to Control Panel -> System -> Hardware -> Device Manager -> Ports (COM & LPT) and selected the card. One of the tabs allows you to set the port as LPT1, 2, or 3, but this had no effect on its detectability by TTL I/Otest. But, under the Resources tab the hardware address(es) of the port are given in Hex format. Converting this to decimal using Window's calculator app (again, as described in the DirectRT manual), I got a port address and entered that manually in TTL I/O test. Then I tried sending a 10 msec TTL code to the EEG system, and by gar it worked! Entering the same port address into a DirectRT script also worked.

I encountered two "gotchas" in getting this to work. The first was that at some point in my testing, the hardware address of the port actually changed. Still haven't figured out if this was after a reboot or unplugging then re-plugging the card (BTW, be sure to use "Safely uninstall hardware" tool in the Taskbar to turn the card off before popping it out), but suddenly I was not getting codes, until I went back to the Hardware Profiler and found that the address had changed (actually, first I bugged Blair and then I figured this out ). The second 'gotcha' was that in TTL I/Otest, at the offset of every code I send, my EEG system registers a '255' code. This does not occur when I send codes in DirectRT, so it's not a problem for me, but it could be distracting/puzzling if you don't know what's happening.

[JEC]

Aaron,

Thanks so much for sharing your experience with this!

John