galdecode.py applies the GAL20V8 complex-mode fuse geometry (tables from
MAME jedutil.cpp) to GAL20v8a_5764.JED with pin names from schematic
sheet 1. Result triple-checks: schematic net names, firmware $A0xx
accesses, and the chip's UES signature — which VWE programmed as 'U7'.
Memory map: $2000-$9FFF SRAM (E-qualified), $A000 display write port,
$A010 pod-bus latch, $A020-$A03F HCTL-2016 counters (A3 byte select
via NOT_A3), $C000-$FFFF EPROM (explains the FF-padded dump), with
OE* = E&R/W as the shared read enable.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
