1985 · Ocean Software

About this page

This minisite was contributed by unorig. It’s agent-generated and needs a human editor. Clone https://github.com/gamesexplained/gamesexplained and follow kit/START.md to curate games/c64/rambo-first-blood-part-ii with me to Gold.

Footprint

Every byte of the C64's 64 KB, one pixel each, 512 to a row. Lit pixels are what this game is: its code, graphics, level data, sound, text, tables and variables, exactly where they sit in memory. Dim areas are screen and working memory; dark is unused.

Status

Tier	silver
Coverage	100 % of the bytes the game uses have a description
Comments checked	Not audited. No audit has checked every comment, and the last sample of 60 comments had 18 wrong, so between 20 and 43 % of the listing’s comments are likely wrong. How listings are checked
Build analysed	Ocean's original disk, mastered 4 December 1985 ("MASTER DATE 04/12/85 NO:014.006.2" on track 18, sector 2), protected by the XROM system of Tequila Sunrise, Belgium; a G64 image
Copy	agent-draft
Tools	host: macOS 27.0 on Apple silicon (arm64), emulator: release v3.13.2, v3.13.2-macos-arm64-gui.dmg (tools/vice-mcp), driven through kit/c64/vice.py and codemap.py; check-emulator 57 of 57 on release v3.14.0 (v3.14.0-macos-arm64-gui.dmg), which booted the disk the same way, disassembler: regenerator2000 (tools/cargo/bin), through kit/c64/r2000.py, publication: Python 3 and Node.js; symbols_export.py, listing.py
Model	claude-opus-5-5
Kit version	0.0.289

How the listing was checked

Every step that measured the Source tab’s comments or made them more accurate, in the order it happened, with the models that did it. Accuracy of the Source explains each step and what the row above makes of them.

Step	By	What it found
Research	claude-opus-5-5	Looked the game up online (its manual, reviews or wiki pages) before reading its code.
Annotation	claude-opus-5-5	Wrote the listing’s comments. 100 % of the program is described, in 925 comments.
Sample 1	claude-opus-5-5	18 of 60 comments wrong, so between 20 and 43 % of the listing is likely wrong. All 18 were then corrected.

likely wrong the sample’s range corrected right, or likely right not yet measured

Contributors

unorig (1 commit)
air (1 commit that changed other games too)

Other places to love this game

Rambo (1985 video game)

What the game does, and where we found it

Read this before annotating code. What the game is documented to do, with verification status against the binary. Statuses: open (documented, not found yet), traced (in the code, could not be exercised; say what was tried), confirmed (in the code, consistent with the emulator), live (observed directly), differs (the code does something else). "Absent" is not a status.

Sources:

The game's own instruction pages (reference/instructions-1.png, reference/instructions-2.png), read 2 November 2026
"Rambo (1985 video game)", Wikipedia, read 2 November 2026
ZZAP!64 issue 10's review as reproduced by GB64's Game of the Week, read 2 November 2026
The C64-Wiki has no page under the game's title (HTTP 404 on 2 November 2026); Lemon64 refused the fetch (HTTP 403).

Features

Feature	Status	Where
Joystick moves Rambo; fire uses the weapon in hand ("PLACE YOUR WEAPON INTO PORT TWO")	live	`read_stick` `$1CD0` ANDs both ports, so either port works; `fire_check` `$19F7`
Space bar selects the weapon	traced	`weapon_select_key` `$19BD`, key code `$3C`; steps to the previous owned weapon. Pressed in the play session; the change was not measured
"S" toggles music and sound effects	traced	`music_toggle_key` `$0CCC`: toggles effects off (`$0D11`) and the voices the music may use (7 or 0)
RUN/STOP toggles a pause	traced	`key_pause_toggle` `$09F8` sets `$0A19`; `irq_panel` then freezes input and silences the SID
Extra weapons lie in the terrain and the enemy campsite	confirmed	four map items (`$0BB7`-`$0BCB`); `item_pickup_check` `$0A1A` adds weapon bits to `$19ED`
Starting weapons (the sources disagree)	traced	weapons 0-2 owned at the start (`$19ED` = 7); which weapon each number is was not tied to a picture
An energy bar; death when it runs out	confirmed	`energy_tick` `$0C89`, energy `$0CC3` from `$30`; damage per hit in facts.md
Free scrolling in every direction over a jungle map	live	`scroll_jungle` `$1C67`; map of 119 by 16 tiles at `$E770`
The POW camp, Banks and the hut opened with the knife	traced	`hut_door_check` `$08D9`: weapon 0 on the hut-door character `$E0`, after the first flight, frees ten POWs (`$0846`). Banks on a cross was not found as a separate object; open
A helicopter; once aboard its fuel runs down fast	confirmed	the fuel is the energy bar: `gunship_fire_timer` `$304E` adds a unit of damage every `$3064` frames
Inside the helicopter only the rocket launcher fires	traced	`heli_fire_rocket` `$3140` fires only with weapon 5
An enemy gunship harasses the flight north	confirmed	`gunship_update` `$3066`; pursues on the second flight (`$3825`); five hits bring it down
Three stages, points for each, the game starts again after the mission	traced	the mission ends on landing from map row `$300` northward with message 4, then `game_start` again (`heli_landing_check` `$356E`)
Name-entry wheel and all-time heroes table	live	`name_entry` `$C367`, `attract_pages` `$C827`; 80 entries at `$B000`/`$B0F0`
Martin Galway's music; nine tunes counted in play	confirmed	twelve tunes and their effects on the driver at `$8100`, played on the page; tune 28 has no caller
Noise draws the enemy	confirmed	explosions and weapon 4 add 5 each to the spawn budget `$119B`

Beyond the documentation

Found in the code, not in the manual.

The loader checks for a cartridge: it writes $8004 and resets the machine if the write does not hold (orientation.md).
Enemies fire more often the further north the screen is (bullet_fire $2586).
The helicopter's rotor loop sounds only with the music switched off (loop_tick $8423).
The credits are the heroes table's default names ($B0F0).

Open questions

Which weapon is which picture: the code numbers them 0-5.
Where Banks is: no object or tile for a captive on a cross was identified.

The symbol map for this game is symbols.json; the listing behind the Source tab is listing.json. Write-ups, facts and symbol maps are CC BY-SA 4.0. The game itself is not hosted here.