Developing PC104-GPIB driver for Pharlap ETS

[ITTengr]

I'm using the NI-488DDK device development kit to develop a driver (user-level implementation) for the NI PC104-GPIB card that will be embedded in a system running Pharlap ETS 12.0. Before I get too far down the road I wanted to ask for some advice on which DDK example to modify and which HW layer code to use.

My initial guess is to use the DOS OS layer example (as you may know Pharlap ETS is a Win32 based kernel). It however uses the PCI based board as its target hardware so those references must be changed. For the PC104 board I'm not sure whether to use the EISA/AT specific files or the TNT chip specific files.

Any guidance in getting started would be appreciated.

Todd

[ScottieB]

Todd,

NI Support will not assist you in making your DDK changes, but I wanted to add in my $.02 to help you get a handle on your task.  Every little bit helps, right?  As far as I understand, PC/104 is exactly like ISA with a different hardware configuration so that's where I would start.  The TNT-only files are probably pretty similar to the AT ones, though.  If you get into a situation of needing to know how the TNT works, you can see the chip reference manual here:

https://www.ni.com/docs/en-US/bundle/tnt4882-programmer-reference/resource/370872a.pdf

As far as the OS layer, I'm clueless.  If it's a single-mode OS (no user-kernel transition) then I think the DOS OS layer example is a good place to start.  If you do have divided User and Kernel mode, maybe the Linux one would be best.

Hope this helps.

Scott B.
GPIB Software

[ITTengr]

Thanks Scott,

After a little more inspection of the DDK code I discovered that the TNT files are included by both the PCI and EISA so it's really just a choice between the PCI and EISA source. The code is not documented very well so it's difficult to determine what function a particular construct does and whether it's needed (perhaps it's obvious to someone who writes drivers more often than I do).

I think the DOS os layer is the right choice too, it's single user, multithreaded, but the gpib code all runs in the same thread. The others are unix based or vxworks. Although I am reviewing them to understand how they use the EISA device.

Appreciate the help

Todd