VIS File Viewer

A lightweight media file viewer for the Tandy/Memorex Video Information System (VIS) — a 1992 multimedia console running Microsoft Modular Windows 3.1 on an Intel 80286 @ 12 MHz, with a Yamaha YMF262 (OPL3) FM synth + R-2R DAC and a Mitsumi 1× CD-ROM.

It is a single Win16 NE executable, bundlable as the shell of any VIS CD/ISO. On boot it enumerates the media files on the disc and presents a hand-controller-navigable browser. Selecting a file plays/shows it using the VIS's native Modular Windows facilities — no persistence (the VIS is CD-only: no hard disk, no save).

Media	Format	How it's rendered
📷 Photo	.BMP / .DIB (8-bit, ≤ 320×200)	GDI StretchDIBits + realized 256-color palette
🔊 Audio	.WAV (PCM→DAC), .MID / .RMI (→ OPL3 FM)	MCI waveaudio / sequencer
🎬 Video	.FLC / .FLI (Autodesk FLIC)	DISPDIB DVA, decoded straight into video RAM (A000)

Why FLC and not AVI?

VIS edutainment titles are full of full-motion video — but inspecting the retail discs (Atlas of U.S. Presidents, Bible Lands, Fitness Partner) shows not a single AVI file: their video is Autodesk FLC/FLIC animation and RLE/DIB sequences blitted via DisplayDib. The ROM's mciavi.drv is vestigial — opening an AVI through MCI returns MMSYSERR_NODRIVER (err 6). So this viewer implements a from-scratch FLC player, which is how VIS video actually worked.

Notable VIS gotchas baked in

• MCI wiring — audio needs the [mci] + [drivers] wave/midi=vwavmidi.drv sections in SYSTEM.INI, or mciSendString open returns err 306 (MCIERR_DEVICE_NOT_INSTALLED).
• MIDI base-level mode — the VIS synth boots responding only to channels 13–16; play a General MIDI file by embedding the GM-System-On SysEx (F0 7E 7F 09 01 F7) as the first event (see tools/prep_midi.py).
• Video performance — three independent ceilings, all addressed for full-frame video: GDI is too slow (DIB_RGB_COLORS ≈ 1 fps, DIB_PAL_COLORS ≈ 5 fps) → use DISPDIB DVA with direct A000 writes; GetTickCount/WM_TIMER are quantized to ~55 ms → pace frames off the PIT directly (~596 kHz on MAME-VIS); per-pixel decode is the real limit → decode in place to A000 and fill RLE runs with rep stos/movs (_fmemset/_fmemcpy).
• 256-color rendering — [tvvga] (lowercase) resolution=320x200x8; StretchDIBits, not SetDIBitsToDevice; bottom-up DIBs; palette realization for the free 236 colors.
• Hand controller — IMPORT hcGetCursorPos HC.HCGETCURSORPOS is mandatory for WM_KEYDOWN routing; poll it from a timer; suppress the native cursor.

Layout

src/        viewer.c (the app) + build_viewer.bat + link_viewer.lnk + mkiso_viewer.py
tools/      prep_image.py (any image → VIS 8-bit BMP), prep_midi.py (SMF → VIS MID)
reverse/    flc_encode.py (test-FLC generator), inspect_real_disc.py (disc recon)
cd_root/    VIS-bootable CD staging: AUTOEXEC, SYSTEM.INI, CONTROL.TAT + test media

Build & run

Requires Open Watcom V2 (Win16 target), Python with pycdlib (+ Pillow for the tools), and MAME with the vis driver and a VIS BIOS dump (vis.zip, not included — provide your own).

# 1. compile the Win16 NE and stage it into cd_root
cmd /c src\build_viewer.bat        # override WATCOM to point at your Open Watcom

# 2. master the VIS-bootable ISO
python src\mkiso_viewer.py          # cd_root/* -> build/viewer.iso

# 3. run in MAME (BIOS vis.zip on the rompath)
mame -rompath . vis -cdrom build/viewer.iso -window -nomax -skip_gameinfo

Adding your own media

python tools/prep_image.py path/to/photo.jpg  NAME      # -> cd_root/NAME.BMP (8-bit, ≤320×200)
python tools/prep_midi.py  path/to/song.mid   NAME      # -> cd_root/NAME.MID (GM-On injected)
# then re-run mkiso_viewer.py

8.3 uppercase filenames; BMPs must stay under ~65 KB (≈ 320×200 at 8-bit).

Credits

Built on the VIS reverse-engineering groundwork from the sibling vis-wolf3d project (toolchain, CONTROL.TAT, DISPDIB/__A000H, PIT timing, palette/rendering gotchas). The VIS BIOS and Modular Windows are property of their respective owners and are not redistributed here.

License

MIT © 2026 Samuele Voltan — see LICENSE.