Dracula

Imagic · Intellivision · 1982

One street, one night, and a thirst that will not keep. Imagic's cartridge rebuilt from the original ROM — every bite, every thrown stake and every minute of the clock behaves as the real machine plays them.

Play now Controls How it was built

DRACULA PRESS ENTER OR SPACE TO BEGIN EASY 1 PLAYER LEFT / RIGHT — DIFFICULTY UP / DOWN — PLAYERS

Press Enter or Space to begin · ←→ difficulty · ↑↓ players

How to play

You are Dracula. Walk the street as a man, fly it as a bat, and drain every victim before dawn. The flask on the right is your blood: it falls all night, twice as fast on the wing, and at 6:00 the sun ends you whatever you have left.

At the controls

Walk←↑↓→ or WASD
Change formSpace / Z
BiteC
Bite & raise a zombieX
PauseP / Esc
StartEnter

The bite

Victims walk the pavement on their own, and a lit window on the top lane will answer a knock: stop beneath it and someone comes to the door.

Catch one as a man, press the button, and the night's count drops by one — three on Easy, six on Medium, eight on Hard to begin with, and one more every night after.

Holding the button down does not repeat — one press is one bite, however long you lean on it. And a quick stab at it can miss altogether: the cartridge looks only once a pass, so a press needs about four frames to be certain of landing.

Two players

Two at a time take the night in turns. When one player is finished the other's street loads by itself, after a wait the cartridge counts out in housekeeping passes — 170 of them, which is a little under eight seconds.

Two at once hands the second player a townsperson to run for their life — I J K L, or a second gamepad.

On a gamepad

The discstick or D-pad
BiteA
Bite & raise a zombieB
Change formX · Y · bumpers
PauseBack
StartStart

The stick is read as the sixteen directions of the real controller's disc, not as eight — the same angles the cartridge sees. Plug in a second pad and it takes the townsperson in the two-at-once game.

He walks a street drawn in perspective. Push the disc left or right and Dracula does not move at all — the pavement scrolls under him. Push up or down and he does not go straight up or down either: the cartridge aims him at the back of the pavement or the front, so he crosses on the diagonal. Captured on the cartridge: north from (69, 60) puts him at (107, 43) — seventeen pixels up and thirty-eight across.

The night

The clock opens at midnight and the street runs on without you. Three things out there are against you — though only the vulture can end a night outright — and one can save you.

The constable

He walks in from the east with a stake and throws it the moment he is close enough. A hit pins you where you stand — the disc, the bite and the bat are all refused — until it wears off.

He does not come out every night. Easy keeps him away on the first, second and fourth; Hard sends him on the very first.

The wolf

White, fast, and released only when the last victim's marker fades. One brush with it and you walk at half speed — not for a while, but for the rest of the night.

The vulture

It hunts the bat and nothing else. Once it has you it carries you west along the sky; the top button shakes it loose. Let it carry you past the edge of the street and the night is over.

The coffin

The graveyard at the end of the street is the only way to bank a night. Sink into it once every victim is bitten — or any time from 5 AM, which is a mercy Hard does not grant.

The blood runs out on its own. One drop goes every minute of the clock on the wing, but only on the odd minutes on foot — so flying costs exactly twice as much blood, on every difficulty. When it runs low Dracula turns white. Bite to refill it; there is no other way.

Built from the ROM

Nothing here is guessed. The cartridge runs inside an instrumented emulator with real controller input, and every mechanic is measured on it — sprite bitmaps, sub-pixel speeds, collision rules, sound scripts, the interrupt's own cycle budget — then reproduced in JavaScript. When the manual and the ROM disagree, the ROM wins.

0mechanics guessed

20test suites, every rule in them captured from the cartridge

17.45frames a game minute — the cartridge's own clock, matched

8 pxthe width of every sprite the hardware draws — only the vulture is doubled

Early-eighties honesty. Reading the ROM turns up things the box never mentioned. The wolf's slow is never counted down, so one brush lasts the night. The sun loads at 5 AM with the minute left at 252, so dawn arrives eighteen frames later instead of an hour. One flag is written to zero and never set anywhere at all. And there is no cross: the hazards are the stake, the wolf and the vulture, whatever anyone remembers. The port keeps every one of those quirks — because that is the game.

The findings are written up in the repository's ROM_TRUTH, from the spawn director's one-in-128 roll to the exact cycle cost of every chunk of the main loop.

Source on GitHub