Technical reference

CDU screens (M5c)

docs/CDU.md

Status: 2026-11-05. The captain's and first officer's CDU screens (VCockpit on LU_CDU_CPT / LU_CDU_FO, 1024 x 852) draw Zibo's PANEL_3D groups "FMC Capt" / "FMC FO" (tools/msfs/build_du.py CDU CDU_FO): the screen background and the text lines Zibo's FMS writes as string datarefs, one per font / colour layer (laminar/B738/fmc1|2/LineNN_L large white, _S small, _G green, _M magenta, _I inverse, _C cyan, _X / _LX / _GX the label row, Line_entry the scratchpad), with Zibo's own CDU fonts.

  • Sources: avionics/src/du/CduSources.ts. The lines come from CduText (what the FMS publishes); until the FMS runs they are blank. The screen background shows with the CDU's bus power (AC transfer bus 1 / 2, pending until the FMS sets Zibo's fmc1_show).
  • X-Plane maps the 548 x 468 panel rectangle onto the screen: the instrument stretches it to the 1.2:1 VCockpit.
  • Compiler fix: gen_text instruments are kept by where they draw (POS + OFFSET): Zibo's large-font lines sit at x 560 with OFFSET_X -540 and were dropped.
  • Layout check: node avionics/scripts/render-du.mjs CDU <dir> draws Zibo's IDENT page text (avionics/test/data/cdu_oracle.json):

IDENT page

Next (M5c): the FMS that writes these lines, the CDU keys (cockpit and keyboard).