Join GitHub today
GitHub is home to over 28 million developers working together to host and review code, manage projects, and build software together.Sign up
Slot 3 ROM space does not float when Uthernet is enabled #418
The slot 3 C3xx ROM space should access the floating bus when the IIe 80 column firmware is switched out. It presently being filled with $00 when Uthernet is enabled. It works correctly if Uthernet is disabled. I also verified that the bus does float on a real IIe with Uthernet card in slot 3.
This causes an issue under ProDOS 1.1 specifically. This version checks for presence of a card in slot 3 by switching out the 80-col firmware and testing for the floating bus. If the value it reads does not change, it will assume a card is present and leave the internal firmware switched out. In Applewin, booting into ProDOS 1.1 and then doing PR#3 will hang if Uthernet is enabled.
Simple test is to use the monitor to switch out the firmware by writing to C00B and then examine C3xx.