Porting OSBDM code to the Spyder?

[asd_vermont]

I haven't looked at every message on the forum, so I apologize if this has been asked before.

In looking at the circuit diagrams for the OSBDM and the Spyder programming tool, they seem to be quite close.  I have several students who own a Spyder (used in our introductory microcontroller course) but they would like to experiment with the SH family and the Softec firmware doesn't support that family. 

So, could a Spyder be re-programmed to become an OSBDM programmer? 

[pgo]

I have looked at porting USBDM to the spyder previously but the port pins used are very awkward.  The USBDM (and OSBDM) code take advantage of using certain pins.  The spyder uses a single pin and a FET for input and output for the BKGD signal.  This presents some problems.  Also,  to re-program the spyder it would be necessary to build a JB16 programmer first, since AFAIK there is no information available about how to update the spyder code through the USB (if this is possible at all).  The required signals are available on a 'bed-of-nail' on the bottom of the board.  There would also be significant speed limitations due to the FET interface used.

So, it's possible but a bit of a pain!

For the above reasons  I haven't pursued this (yet).

bye