BillO wrote:
Why did WDC stop making this chip?
There was very little demand for the 65C802. Anything system that was scratch-designed and needed the 65C816 functionality used the 65C816. So the only other use for the '802 was as an upgrade to a 65C02 system. The last I recall that a 65C802 was available from stock was c. 1995.
GARTHWILSON wrote:
Daryl Rictor (8BIT here) had a PCB design to use SMT parts to make an '816 module that would plug into a 6502 socket and act like an '802, but right then, the '816 became unavailable in PQFP, and the PLCC version was too big.
The PLCC version could probably be made to work by soldering the package to the PCB instead of socketing it. The footprint would be slightly wider than a PDIP-40 package, though.
The one significant caveat is that the 65C802 functionality obfuscated the invalid address bus cycles generated by the 65C816, as well as did not emit the bank address during Ø2 low. Also, since the 65C802 was pin compatible with the WDC 65C02 (and almost pin compatible with non-WDC 65C02s) there is the matter of the SYNC output that doesn't exist with the 65C816 (VDA and VPA take SYNC's place). Any adaptation of the 65C816 to a 65C02 device has to take this into consideration.