openttd_amiga_68k

KO | EN

gitlite — search

#github #typescript #hacktoberfest #c #docker #animation #macos #computer-vision #php #chatbot

openttd_amiga_68k

(★ 9)

Native AmigaOS 68k (OCS/AGA/P96/020+/24M RAM+) port of OpenTTD 1.0.5 - with multitasking, sounds, music, custom AI, no extra files needed

File Explorer

ZIP Download

- - t_printf.c
- apply-amiga-patches.py
- build-both.sh
- build-nofpu.sh
- build-openttd.sh
- build-with-ice-retry.sh
- make-info.py
- make-release-all.sh
- make-release-zip.sh
- make-splash.py
- pc-fixes.py
- pc-fixes.sh
- pc-fixup-makefile.sh
- pc-source-list.sh
- tgp-remove-pow.py
- - amiga_adpcm.c
  - amiga_adpcm.h
  - amiga_audio.c
  - amiga_audio.h
  - amiga_camd.c
  - amiga_camd.h
  - amiga_ehb_data.h
  - amiga_gfx.c
  - amiga_gfx.h
  - amiga_m.cpp
  - amiga_m.h
  - amiga_mscan.c
  - amiga_mscan.h
  - amiga_s.cpp
  - amiga_s.h
  - amiga_ttd_version.h
  - amiga_v.cpp
  - amiga_v.h
  - fp_conv.c
- agabench.c
- agac2p.c
- againput.c
- c2p1x1_6_c5_bm_040.s
- c2p_glue.s
- c2p_rect.s
- exctest.cpp
- fptest.c
- gfxtest.c
- paulatest.c
- zlibtest.c
- - artic.py
  - dump0.py
  - dump4.py
  - nfoparse.py
  - retram.py
- poltrams-original.grf
- poltrams.grf
- README.md
- amiga-68k.diff
- README.md
- newgame.png
- openttd_68k_ocs.png
- openttd_68k_p96.png
- titlescreen.png
- window-mode-workbench.png
.gitattributes
.gitignore
amiga_openttd2.png
BUILDING.md
COPYING
README.md
splash.dat

# Use via CDN

jsDelivr

jsDelivr serves any public GitHub repository as a CDN with zero setup. Pick a version and a file to get a ready-to-paste link and snippet.

Version

File

Link

Example

// repository documentation

Was this content helpful?

★ 0 (0 ratings)

A native port of OpenTTD 1.0.5 to classic AmigaOS 3.x on 68k, with its own video
driver written against Intuition and graphics.library. No SDL, and no RTG card
required — it runs on plain AGA, and on OCS/ECS too.

Playable. See the [releases](../../releases) for the ready-to-run archive.

![OpenTTD running on an emulated A4000/040 with AGA](https://raw.githubusercontent.com/angree/openttd_amiga_68k/main/screenshots/newgame.png)

## What works

Map generation, save/load, the menus and scenario editor, building rail, road,
stations and depots, running vehicles and giving them orders. Full mouse
(including right-drag scrolling), keyboard and arrow-key map scrolling.

**Computer opponents** — a native C++ AI written from scratch (neither the
in-engine nor the Squirrel AI would run on this port): cargo trains between
industries, passenger trains between towns, and local bus routes inside towns,
expanding as they get richer.

**Sound** through Paula, no software mixer: each effect goes straight to one of
the four hardware channels and DMA plays it, so the CPU does nothing once a sound
starts. **Music** is the game's own soundtrack, streamed from disk as ADPCM WAV
on two Paula channels. Enable with `-s amiga -m amiga` (`-s null` / `-m null` for
silence).

Resolution is selectable in Game Options and takes effect immediately: `320x256`,
`352x272` and `640x480` in AGA; `320x256` and `352x272` in **OCS**; then RTG
modes if a card is present. The interface font follows the resolution.

The **OCS/ECS** modes are Extra Half-Brite (6 bitplanes, 64 colours, the upper 32
forced to half-brightness copies of the lower 32). That means a quarter less
chunky-to-planar work, half the Chip RAM for the bitmap, and — because EHB exists
on OCS/ECS — a chance of running on an A500/A600. They are lores only: the sixth
bitplane *is* the half-brite control, and OCS/ECS cannot fetch six planes at
hires bandwidth. Switching between AGA, OCS and RTG needs a restart (the choice
is saved immediately and shown on screen).

![OpenTTD in an OCS/ECS Extra Half-Brite mode](https://raw.githubusercontent.com/angree/openttd_amiga_68k/main/screenshots/openttd_68k_ocs.png)

Since 1.1.0 the game can also run **in a window on the Workbench** instead of
opening a screen of its own, so you can keep working while it is up. Turn it on
with `amiga.fullscreen` (the default keeps the screen, so upgrading changes
nothing). In window mode the resolution list sets the window's starting size —
there is no screen mode to pick, since the window inherits the Workbench's.

![OpenTTD running in a window on the Workbench](https://raw.githubusercontent.com/angree/openttd_amiga_68k/main/screenshots/window-mode-workbench.png)

**NewGRF** sets load since 1.2.0, and with them the first new vehicle type this
port has had: **trams**. OpenTTD 1.0.5 reads GRF container v1 only, and
everything published since 2012 uses container v2 — which is why modern sets
came back as "invalid NewGRF" regardless of what was in them. The v2 reader is
backported (8bpp, zoom 0), together with the Action 0 properties GRFv8 sets
rely on. Switchable in Advanced Settings → Amiga → *NewGRF*, default on; turning
it off skips the scan and saves the memory a set costs (~136 KB for a small
one). Action 14 is not implemented, so a set's parameters must be written into
`openttd.cfg` by hand.

A tram set ships with the release, so the tram tools are on the road toolbar
from the first game.

**If it runs too slowly, use a lores mode** — it converts a quarter of the pixels
of `640x480` and is not interlaced. On an 030, lores is the only playable
configuration, and even then generate a small map.

**Loading is much faster if you have RAM to spare.** With more than 50 MB free,
the game reads each data file once into memory instead of fetching it off the
disk in small pieces, which is what made startup take minutes on a real hard
drive. Advanced Settings → Amiga → *Fast load*, on by default; below 50 MB free
it switches itself off and loads the old way, so a 24 MB machine is unaffected.

## What does not

- Memory use is high: ~24 MB total required. The OCS modes cut colours, not
  sprite size, so they do not yet lower it — half-size graphics are the next step.

## Requirements

- **68020 minimum to start, no FPU needed** — but starting and playing are not
  the same thing. For a game that actually plays, expect a **68030/50 with an
  RTG board** or a **68040 with AGA**; 68060 for full speed. Tested on a bare
  020, an 030 with no coprocessor, and an 040. (The FPU requirement was removed
  in 0.7.0 — the cause was
  `printf` pulling FPU code into libnix's prologue, not the maths; building with
  `-mcpu=68020 -msoft-float` fixes it. Only map generation uses floating point.)
- **AGA, or OCS/ECS, or a Picasso96 / CyberGraphX RTG card.** RTG is worth having
  if you own one: the chunky 8bpp buffer goes to an 8bpp RTG screen essentially
  unchanged, skipping chunky-to-planar entirely.

![OpenTTD on a Picasso96 RTG screen](https://raw.githubusercontent.com/angree/openttd_amiga_68k/main/screenshots/openttd_68k_p96.png)
- **24 MB Fast RAM** (won't start on 4 MB Fast + 16 MB Z3; does on 8 + 16).
  AmigaOS 3.0/3.1, ~30 MB free disk.

Nothing from the original Transport Tycoon Deluxe is needed — the archive bundles
OpenGFX and OpenSFX and runs as unpacked.

## Why 1.0.5

The last comfortable base for this target: C++03 (buildable with bebbo's
m68k-amigaos GCC 6.5, where later OpenTTD needs C++11/17/20), an 8bpp blitter by
default (a chunky palette buffer, exactly what a chunky-to-planar converter
wants), all external libraries optional, and the first release that is legally
redistributable via OpenGFX/OpenSFX. 1.0.5 still carries OpenTTD's own
Amiga/MorphOS scaffolding (removed upstream in 2019); what never existed upstream,
and what this repo adds, is a real Amiga video/sound driver and the native AI.

## How the display works

OpenTTD draws into a chunky 8bpp buffer in Fast RAM (`_screen.dst_ptr`); getting
that onto an AGA screen is the only Amiga-specific step. The screen owns one
contiguous Chip RAM block for all bitplanes (`SA_BitMap`), conversion uses Mikael
Kalms' 68040 `c2p_rect`, and only changed rectangles are converted (from
OpenTTD's own dirty-block list). On an A4000/040/25 a 320x256 frame is ~30 ms
through c2p — but a full-screen repaint almost never happens in play.

## Building

See [BUILDING.md](BUILDING.md) and read it first. The toolchain has traps that
produce silently wrong code rather than errors: several files miscompile at `-O1`
and must be built at `-O0`, `-O2` breaks C++ exception unwinding, and zlib
corrupts data above `-O0`.

## Credits

- Written by angree, with Claude (Anthropic) used heavily throughout — driver and
  AI code, build work, and the isolation testing that tracked down the toolchain
  miscompilations.
- OpenTTD, GPL v2 — <https://www.openttd.org/>
- Chunky-to-planar by Mikael Kalms, public domain —
  <https://github.com/Kalmalyzer/kalms-c2p>
- OpenGFX / OpenSFX by the OpenTTD community
- Tram set: **PolTrams** by Sojita, Voyager One (graphics) and McZapkie (NML
  code, graphics), GPL v2 — shipped in a modified form (vehicles renamed to
  their non-Polish equivalents, freight trams reduced to one cargo). The
  modification is noted in the set's own description in the NewGRF window.
- bebbo's amiga-gcc — <https://github.com/bebbo/amiga-gcc>

## Licence

GPL v2, following OpenTTD. Kalms' c2p is public domain and keeps its own terms.

openttd_amiga_68k

Owner Repos

File Explorer

# Use via CDN

Was this content helpful?

Recent Feedback

openttd_amiga_68k

Owner Repos

File Explorer

# Use via CDN

Was this content helpful?

Recent Feedback

Download README