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>
Organize the restoration source material under docs/hardware/:
- 9 board photos (renamed from Signal timestamps, index in README)
- Scans_018-014.pdf: 7-sheet VWE schematic set (RIO_1407 CPU/power/IO,
PBE_1401 buttons, KEY_1402 keypad, DSP_1408 display, AMP_PLT 1413 amp)
- GAL20v8a_5764.JED: fuse map of the 1407's U7 memory decoder
README documents the board family, the 68HC11 memory map decode path,
the pod-bus signal set and jumper addressing, and cross-links PROTOCOL.md
and rio-firmware/.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
CydandClaude Fable 5