Callback64

CALLBACK: Operation Internot

less scroll. more soul.

A Commodore 64 game about redemption, touching grass, and liberating the blue-light zombies from the iron grip of the feed. You'll meet innocents trapped in the algorithm and rage-baited loyalists sent to derail your mission.

Win them all with kindness (and a flip phone).

---

The year is 2026. The feed has won.

The algorithm hums in its server cathedral, harvesting every eyeball on Earth. Doomscrollers — chins down, souls dim — wander the streets distracted, until the next hazard swallows them.

Then Commodore returns, and drops the Callback 8020. No feeds. No ads. No algorithm. Just calls, texts, and SID ringtones.

The algorithm panics. Its flop cameras line the streets, watching your every move, and it rage-baits the faithful into the Order of the Breadbin — a militia of true believers with one article of faith: a phone? not from my Commodore! Alerted by the algorithm, they take to the rooftops and the pavements with armfuls of breadbin C64s, and they throw them at anyone carrying a Callback.

One man grabs a satchel of phones.

Your mission: Deliver the Callback.

---

What you actually do — Stage 1: Neon City

Walk up to a doomscroller and give them a phone. That is the whole game and it is harder than it sounds.

Twenty souls. Each one costs a phone out of your satchel, and the satchel is small. Run dry and you are back to the barn to resupply while the street keeps scrolling without you.

Mind the holes. Doomscrollers, gaze captured by a glowing screen, walk straight into Colorado-sized potholes, or drown in puddles. Three heads sit in the corner of your HUD and hollow out one by one as the street takes them. Lose three and the street goes quiet for good.

The Order throws computers at you. Long arcs from the rooftops to duck, and flat kneecap sliders along the pavement to jump. Three hits and you are down.

Your only countermeasure is a SID ringtone. The blast stuns the radicalised breadbin throwers where they stand — three seconds of ringing clarity, and that is your window. Walk up to the man who has been throwing seventy-pound computers at your head, reason with him, win him over with a phone. Convert one and he hands you a ringtone back in kind.

Ringtones are rare. You earn one for every third soul saved, and if you run out entirely you can count on your dog to turn up with a fresh SID tune.

The girlfriend. She makes her entrance once you have cleared the buildings of their doomscrollers, and she comes only when you need her. She restores your health and lifts your spirits.

Then the golden cassette. Save your twenty and it appears exactly where the last soul was standing. Pick it up and the street changes. The Order goes into a frenzy, sensing defeat: you can still stun them with a ringtone blast, but they are past reasoning with now. Every post they hold becomes a thrower, machines start arriving from off screen on both sides, two in the air at once — and you have thirty seconds to reach the exit. What began as a rescue becomes an escape.

---

Where it is at

Stage one, Neon City, is playable start to finish. Twenty souls, the cassette, the sprint to the exit, and everything above.

A boss battle for the end of Neon City and a second, vertically scrolling level are in progress. The engine already loads levels as data — each one carries its own character set and its own cast — so stage two will be a genuinely different place rather than a reskin.

---

Technical specifications

What you need to play

Machine	Commodore 64, or an Ultimate 64 / C64 Ultimate
RAM Expansion Unit	Required. Any REU — a stock 1700 is plenty
Controls	Joystick in port 2
Video	PAL native; NTSC supported

The REU is not optional and not decoration. The game refuses to start without one and says so on the title screen. It uses 41,296 bytes and never leaves the first 64 KB bank, so present and big enough are the same test — if a machine has an REU at all, it can run this.

Two ways to play:

• Cartridge (.crt) — everything aboard. Start it and go.
• Disk (.d64) — mount it as a drive. The game reads its CONFIG and world files from the boot drive at start-up, so injecting the bare .prg from the Ultimate menu without a mounted disk will not find them.

Emulator: VICE x64sc with -reu -reusize 16384 runs it faithfully.

How it was built

The game is roughly 5,000 lines of hand-written 6502 assembly in a single source file, assembled with 64tass.

Everything that is not code is data, and all of it was authored in a suite of browser-based tools written for this project:

Tool	Authors
World Forge	levels — tiles, collision, spawns, parallax strips
Sprite Forge	characters and animation clips
Groove Forge	SID music
Screen Forge	title and splash artwork
SFX Forge	sound effects

Python 3 pipelines compile those authored files into game data: sprite banks, music, wave tables, splash bitmaps and complete world files. Nothing is hand-poked; if the art changes, a rebuild carries it through.

Every build is verified in VICE before it reaches hardware — headless runs with screenshots read back and pixel-diffed against the previous build, audio captured and analysed, and soak tests of hundreds of millions of cycles. Real hardware is still the final say, and two bugs in this game's history were hardware-only.

Under the hood

For anyone who cares how the sausage is made:

• The REU does the drawing. An interrupt at raster line 251, down in the bottom border, DMAs fifteen rows of characters and fifteen rows of colour RAM out of expansion memory and into the screen every single frame. The parallax sky strips rotate inside the REU rather than being rebuilt by the CPU — two transfers instead of two thousand cycles of copying.
• Magic Desk, not EasyFlash, and deliberately: EasyFlash answers I/O2 at $DF00 with its own RAM, which is exactly where the REU registers live. An EasyFlash cartridge and an REU cannot coexist. Magic Desk keeps to $DE00 and leaves the REU alone.
• Levels are data, all the way down. A world file carries its own character set, its own collision plane, its own spawn table, its own parallax strips — and its own sprite bank. Stage two can be a top-down game with an entirely different cast without the program knowing anything about it.
• Sprites are two-layer: a multicolour body under a hires ink outline, which is what gives the characters their edge. All eight hardware sprites are spoken for, so the stationary rooftop figures are painted into the character set instead — buying back the units the moving cast needs.
• SID music at about 125 BPM from a custom driver, with a ringtone system that shares voices with the score.

Trademarks

Callback: Operation Internot is an independent game and is not affiliated with, endorsed by, sponsored by, or associated with Commodore International Corporation or any of its products. “Commodore” is a trademark of Commodore International Corporation. All trademarks are the property of their respective owners and are used for identification and reference purposes only.

Any resemblance of characters in this game to real-world counterparts is purely coincidental. (Probably.)

Credits

Bill Stevens — design, story, artwork, music, level authoring, the entire browser tool suite, and every decision that mattered.

Claude (Anthropic) — 6502 implementation and debugging, working from Bill's designs, his art and music files, and his reports from running each build on real hardware.

The collaboration is worth being straight about: the game was designed, drawn, scored and directed by a person, and the assembly was written by a machine that was told what to build and then told, repeatedly and specifically, what it had got wrong on a real Commodore 64.

---

*less scroll. more soul.