ok, to conclude my confusion... I make this circut, attach my controller to it, like the diagram shows. plug it into the serial port, and use some serial software? I wouldnt need a pot or anything else because i have this circut?
There is a 10k pot on that circuit. That circuit is all you need to get it talking to your RS-232C COMM port
It really depends on the operating system you are using. Since most of the people out there are trying to drive these things with Microsoft's Windows OS, most of your concerns are moot. Microsoft Windows OS, since Windows 2000, no longer allows for memory mapped I/O. This is instead handled by a messaging architecture managed by the kernel and the driver. However, in the case of a USB serial and USB parallel port, since these are emulations of LEGACY memory mapped I/O devices, almost all drivers include a method for emulating such behaviour (they map an address through the kernel you can use). So, the USB Serial Port still responds to bit banging on the 3f8,2f8 etc. I/O ranges. However, you are still left with the problem on Windows OSs regarding getting *at* this layer, since user-mode applications are *not* allowed to directly access I/O port. In that case, you need to use a DLL like Portio.dll (many freeware and opensource stuff out there) to pass the data from user-mode to kernel-mode for you. It's not as easy as just banging bits anymore unfortunately....
Yeh normally so we can get our high speed low-CPU interface on NT, i use an IOPM modifing device driver (see a DDJ artical). This modifies the IOPM for the proccess, so we can write any memory address we want. What i was poundering is, with these USB devices, is the memory mapped IO still accessable, from what you are saying this sounds like a yes.
