VDB: honor the VGA-DAC pixel-mask (RP drives it; BT left it 0xFF); park Mac mirror

RP experiment finding: RP runs on the BT pod emulator (shared MUNGA stack) but
its cockpit VDB heads mis-decode. Root causes captured live (VDB_PALDUMP +
vpxresp log): (1) framebuffer identical to BT (mode 0x111, 640x480); (2) RP
loads pal0 (BT's dynamic color-radar palette) as ALL ZEROS -> radar head black;
(3) RP actively drives the VGA-DAC pixel-mask register that BT leaves at 0xFF,
and pal_draw ignored it -> likely the MFD garble.

Device change: pixel-mask writes now log their VALUE on change
("# VDB pixel-mask[gN] = 0xXX"); pal_draw ANDs the palette index with the
group mask under VDB_APPLYMASK=1 (default off = BT-identical); masks default to
0xFF in vdb_reset so an un-driven group still decodes. Built clean under MINGW64.

Also: Mac Console 4.10 retired from regular use (host .NET console is the daily
driver); tap2_mirror.py PARKED with revive notes for console A/B only. The
SendToRxAdapters registry stays set (serves the .NET host console).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

emulator/NET-NOTES.md

@@ -533,6 +533,14 @@ Revert: `Remove-ItemProperty ... -Name SendToRxAdapters` + service
 bounce + pod relaunch. Host connect/disconnect churns netnub (exit +
 ~60s relaunch) -- expected.
 
+**MAC CONSOLE RETIRED / MIRROR PARKED (2026-07-10, operator decision):** the
+SheepShaver Mac Console 4.10 is no longer in regular use -- the host-side .NET
+TeslaConsole is the daily driver (direct pod link, no mirror). tap2_mirror.py
+is PARKED, kept only for running the Mac console alongside the .NET one for
+console A/B testing; revive per its header + the section below. The
+SendToRxAdapters registry stays SET (it serves the .NET host console). Nothing
+to revert unless a Mac-console A/B is needed.
+
 **BOTH CONSOLES AT ONCE — WORKING (2026-07-10, `net-tools/tap2_mirror.py`):**
 keep SendToRxAdapters set (host console works) and run the mirror
 daemon, which turns TAP2's free application side into a userspace

emulator/net-tools/tap2_mirror.py

@@ -1,5 +1,15 @@
 #!/usr/bin/env python3
-"""Pod->Mac mirror for the SendToRx era: with Npcap's SendToRxAdapters set
+"""[PARKED 2026-07-10] The SheepShaver/Mac Console 4.10 is retired from
+regular use -- the modern host-side .NET TeslaConsole is the daily driver
+(it talks to the pod directly via the bridge IP + SendToRxAdapters; no
+mirror needed). Keep this tool for the ONE case it exists for: running the
+1996 Mac console ALONGSIDE the .NET console for A/B testing. To revive: start
+a pod, then `pythonw net-tools/tap2_mirror.py`, and bring up SheepShaver +
+Console 4.10 (see NET-NOTES.md "BOTH CONSOLES AT ONCE"). Verified working
+2026-07-09 (Console 4.10 ran a full mission through it). Constants at top
+(pod NE2000 MAC, TAP2 GUID) may need refreshing if the adapters change.
+----------------------------------------------------------------------------
+Pod->Mac mirror for the SendToRx era: with Npcap's SendToRxAdapters set
 on the Network Bridge (so the host .NET console hears the pod), the pod's
 injected frames no longer reach the TAP members -- SheepShaver goes deaf.
 Every other path still works. This daemon closes the one missing hop:

emulator/vpx-device/vpxlog.cpp

@@ -1326,6 +1326,10 @@ static void write_bmp(const char *path, const unsigned char *rgb, int W, int H)
 static void pal_draw(HDC dc, int g, int cw, int ch, bool dump) {
     const int W = 640, H = 480;
     static unsigned char img[640 * 480 * 3];
+    /* VDB_APPLYMASK=1: AND the palette index with the group's VGA-DAC
+     * pixel-mask (default 0xFF = no-op). RP drives this mask actively where
+     * BT leaves it 0xFF, so honoring it may unscramble RP's MFD heads. */
+    static const bool apply_mask = getenv("VDB_APPLYMASK") != NULL;
     const uint8_t *fb = vga.mem.linear;
     Bitu mask = vga.draw.linear_mask ? vga.draw.linear_mask
                                      : (vga.mem.memsize ? vga.mem.memsize - 1 : 0);
@@ -1348,6 +1352,7 @@ static void pal_draw(HDC dc, int g, int cw, int ch, bool dump) {
                 else             { idx = (px >> 8u) & 0xFFu;              /* wins 5-9: one mono MFD */
                                    pg  = (g <= 6) ? 1 : 2;                /* = one color wire of a  */
                                    chn = (g <= 6) ? g - 5 : g - 7; }      /* head (pentapus split)  */
+                if (apply_mask) idx &= vdb_pal[pg].mask;
                 const unsigned char *e = &vdb_pal[pg].ram[idx * 3u];
                 if (chn < 0) {
                     d[0] = (unsigned char)((e[0] << 2) | (e[0] >> 4)); /* 6-bit DAC -> 8-bit R */
@@ -2533,7 +2538,17 @@ static void vdb_write(Bitu port, Bitu val, Bitu /*iolen*/) {
             vdb_data_count++;
             break;
         case 0: /* pixel-mask */
-            p.mask = v; vdb_note("pixel-mask set");
+            /* RP drives this VGA-DAC pixel-mask register actively (BT leaves
+             * it at 0xFF); log the VALUE on change so we can see how RP gates
+             * the palette index, and honor it in pal_draw under VDB_APPLYMASK. */
+            if (v != p.mask) {
+                p.mask = v;
+                if (vpx_fp) { vdb_flush_data(); flush_run();
+                    fprintf(vpx_fp, "# VDB pixel-mask[g%d] = 0x%02X\n", g, v);
+                    fflush(vpx_fp); }
+            } else {
+                p.mask = v;
+            }
             break;
         case 1: /* read-address */
             p.raddr = v; p.sub = 0;
@@ -2554,6 +2569,9 @@ static Bitu vdb_read(Bitu port, Bitu /*iolen*/) {
 }
 static void vdb_reset(void) {
     memset(vdb_pal, 0, sizeof vdb_pal);
+    /* pixel-mask defaults to 0xFF (no gating) so an un-set group decodes
+     * normally; the game overwrites it if it drives the mask (RP does). */
+    for (int g = 0; g < 3; g++) vdb_pal[g].mask = 0xFF;
     vdb_splitter_on = false; vdb_data_group = -1; vdb_data_count = 0;
 }