demarc — minnberg.se

Intro

Main goal: Make it easy to watch oldschool (PAL) demos

Supported systems:

C64, Amiga, Atari ST, Amstrad CPC, ZX Spectrum, Megadrive, SNES, Atari 2600, Atari XL, Tic-80

Runs multiple demos in order or shuffled
Shows demo meta data as overlay
CRT shader (Lottes) for "authentic" look
Can load disk images and executables
Right-Alt/Ctrl hotkey for disk switch etc
Can run multiple files at once in a grid
Linux: Pause screen blanker and handle media keys

Install (Linux, Mac, Windows)

You need rust.

cargo install --git https://github.com/sasq64/demarc.git

Download (Windows)

Pre-built windows binary here

IMPORTANT: Demarc downloads and links DLLs at runtime, which often makes Windows flag it as malware and silently delete it. Add an exception to your settings, or switch to a sane operating system.

(Another note to windows users; if you really don't want to use the command line, you can drag and drop demos onto the demarc executable to run them).

Prepare

Set your monitor to 50Hz if possible.

Run

demarc --help

demarc <some_demo>

demarc --aga --shuffle Amiga/

TIP: Download all intros from https://intros.c64.org and run

demarc --grid=4x3 --shuffle intros_c64_org_12596_full

Demo Packs

CSDb Top demos

Shortcuts

Right Alt or Right Ctrl +

D = Swap disk
SPACE = Next file
S = Change scaling
B = Change border
I = Toggle Info
T = Screenshot
P = Pause/Resume
R = Reset
C = Toggle CRT filter
W/SHIFT-W = Warp 10s/30s
J = Toggle Joystick/keyboard

For grid:

TAB = Next emulator
SHIFT+TAB = Previous emulator
ENTER = Maximize/Unmaximize
A = Select all emulators
SHIFT+N = Next file in all emulators

Details

File collection Logic

Recurse all directories on the command line
If demo.m3u file found, that directory is added and not recursed
If disk images found in a directory, that directory is added and not recursed
If executables found in a directory, each of the executables are added

Command line arguments

Usage: demarc [OPTIONS] [FILES]...

Arguments:
  [FILES]...
          Path to the files to load

Options:
      --scale <SCALE>
          How to map emulator screen onto window

          Possible values:
          - stretch: Fill the window, distorting the aspect ratio
          - fit:     Preserve aspect ratio, adding letterbox/pillarbox bars
          - zoom:    Preserve aspect ratio, cropping top/bottom or left/right to fill

          [default: fit]

      --border <BORDER>
          How to fill the border outside the image

          Possible values:
          - stretch: Stretch the edge pixels outward into the border
          - black:   Fill the border with background color

          [default: black]

      --shuffle
          Shuffle the list of files into a random order

      --info <INFO>
          When to show overlay info text

          Possible values:
          - always:   Always show demo info on start
          - never:    Dont show demo info on start
          - on-multi: Show demo info on start with multiple files

          [default: on-multi]

      --aga
          Amiga: Force AGA (A1200 with 8MB Fast RAM)

      --ste
          Atari ST: Force STE

      --fast
          Amiga: Force high specs (68030 + FPU)

      --xmem
          Amiga/Atari ST: add extra memory

      --fast-load
          C64: Always use JiffyDOS to load
          Amiga: Turn off disk rotation emulation

      --silent-drive
          Amiga,C64,Amstrad: Dont produce disk loading sound

      --window
          Open windowed instead of full screen

      --max-time <MAX_TIME>
          Max number of seconds to play a file before skipping

      --force-vsync
          Force vsync, slowing down or speeding up emulation to fit

      --latency <LATENCY>
          Max queued frames. Lower values = better input response

          [default: 2]

      --extra-options <EXTRA_OPTIONS>
          Extra options to add to libretro

      --grid <GRID>
          Render multiple emulators in a COLSxROWS grid, e.g. --grid=5x4

      --clear-color <CLEAR_COLOR>
          Background clear color as a hex string, e.g. `#003` or `000080`

          [default: 000033]

      --reu
          C64: Add ram expansion unit (16MB)

      --cbm-variant <CBM_VARIANT>
          Commodore variant (Only C64 well supported)

          Possible values:
          - c64:  Default Commodore C64
          - c128: Commodore 128
          - dtv:  C64 DTV Stick

          [default: c64]

  -h, --help
          Print help (see a summary with '-h')