I appreciate the good ideas there on ways to stop collision.
Tried the double buffer idea with table data change right after first slave write, while holding off the master read long enough to get this done. Went along pretty good for awhile, but still ended up with some corruption, hopefully this isn't a hardware problem creeping in.
Looks like I,m going to have set and clear a register upon entry into and out of the interrupt, then have the slave check that, so that a write won't occur while reading. Also in the same way, will have to check against the slave writing data, to make sure a read won't occur while writing. Tried this and when a deliberate collision course was set, the code locked up, so more work required on this angle.
Another thought would be to call for the data upon initiation of the interrupt, although I have seen many reminders on this forum to keep intterupt routines short. So how short is short?
Right now, the data from the slave is strictly an excersise in using and viewing the Pic I2C Master to Pic Slave relationship/code.