UNC 64 A GAME FOR MAC, PC AND LINUX

THE 1980s COMPUTER EXPERIENCE SIM

A computer that fits in your head.

UNC 64 is a story game about programming a real 8-bit computer. You, a modern-day software engineer, inherit your uncle's old 8-bit computer. You switch it on, and wake up in 1984 at the same desk. There's a tape deck, a monthly computer magazine, a manual full of your uncle's notes, and a lot of programs to write.

16K to start. 64K to earn. A 1 MHz CPU. One manual.
You can know all of it.

Read the devlog See the room

COMING SOON · MAC, PC AND LINUX · IN DEVELOPMENT

DEMO · CLICK TO TYPE

The real machine: the same emulator as the game. It types a little BASIC to itself until you click the screen. Then it's yours. Try 10 PRINT "HELLO", 20 GOTO 10, RUN, then CTRL+C. Or GR:CIRCLE 160,80,60. HELP lists the keywords.

The desk at night: a beige UNC 64 with green text on its CRT, a desk lamp, a ring-bound manual, a tape deck and a snowy courtyard outside the window. The desk in daylight: the UNC 64 with green text on its CRT, a ring-bound manual, a tape deck and a courtyard of brick apartment blocks outside the window.
THE DESK · WORK IN PROGRESS RENDER

The machine

Relive the glory days of 6502 programming
Spec sheet · You start on a UNC 16 and earn the rest
UNC 16 (your uncle's box)UNC 64 (fully upgraded)
Memory16K64K, after you solder in the expansion
Screen40 × 25 green text in UNSCII, your own character sets, a 320 × 200 bitmapThe video board: hardware sprites, smooth scrolling, background layers
SoundA beeper with a tone timer and a noise sourceA three-voice sound chip and a speech synthesizer: SAY "HELLO"
StorageCassette tape, real load timesFloppy drive with its own DOS, then a hard disk
LanguageInteger BASIC in ROMExtended BASIC: floats, graphics, sound
ToolsLine editor, PEEK and POKE, an assembler on tapeScreen editor, monitor, debugger
CPUA fantasy chip in the 6502 family at 1 MHz: a fast page, and a fixed cycle table every leaderboard is scored against.
Programmer's Reference Guide · Appendix B
$0000-$00FFFAST PAGE
$0100-$01FFSTACK
$0400-$07FFSCREEN
$0800-$3FFFUSER RAM 16K
$C020BORDER COLOUR
$C3F0-$C3FFRESERVED
$E000-$FFFFBASIC + SYSTEM ROM

not reserved. it answers. —U

The manual

Free download · PDF
The cover of the UNC 64 Programmer's Reference Guide: UNC 64 in big letters over a red and yellow band.

The UNC 64 Programmer's Reference Guide. The whole machine in 89 pages: every register, every instruction, every ROM routine, UNC BASIC and the assembler.

It's the same book as the ring binder on the desk in the game, set in the same type. It's also the machine's specification: every program listing in it is assembled and run against the emulator, so if the book says it works, it works.

Print it, punch it, put it in a binder. It's free.

Download the PDF

A4 · 89 PAGES · 2.3 MB · REV A

start here. —U

The story

1984 · a bedroom · no deadlines

You're a software engineer. Your days are prompts, pull requests and systems too big to hold in your head. Then your uncle's old computer arrives in a box, with odd tapes, a ring binder full of his handwriting, and a program he never finished.

You switch it on. You wake up in 1984, in a bedroom that's yours and isn't. Mom calls you for dinner through the door. The machine on the desk is the same one.

Every month a new issue of 8-Bit Monthly lands in the mailbox, with type-in listings, challenges, letters and mail-order ads. You save up for a floppy drive. You learn machine code because BASIC is honestly too slow. Somewhere in the memory map, an address that should be empty answers back.

How it plays
  • Write real programs on a real emulated machine. Every puzzle is checked against a spec and scored in cycles.
  • Sixteen programs carry the story, from your first PRINT to a demo party.
  • Earn your tools: the screen editor, the assembler, the disk drive, the 64K upgrade.
  • No deadlines and no fail states. Sleep, and the next issue arrives.
  • Just you and the machine.

PEEK(50161) = 86 ???

The room

Locked cameras · three times of day
The whole bedroom: bed, desk with the UNC 64, window, bookshelf, corkboard, calendar and clock.
THE ROOM
Close-up of the CRT showing a BASIC listing called CAVERN RAID.
THE SCREEN
The UNC tape unit with its counter at 047 and a rack of hand-labelled cassettes.
TAPE UNIT · COUNTER 047
An open computer magazine with a type-in listing, a letters page and an ad for a program generator, beside a photocopied zine.
8-BIT MONTHLY · SCANLINE #2
The ring-bound manual open at the memory map, with a reserved address range circled in red.
THE MANUAL · APPENDIX B
The computer opened up: the main board with empty 64K sockets, a soldering station and a memory expansion kit.
THE 64K UPGRADE
A shelf with a floppy disk box, cassettes and back issues of the magazine.
THE MEDIA SHELF
A wall with a quartz clock, a March calendar and a corkboard with a challenge clipping, a for-sale ad and a postcard.
CLOCK · CALENDAR · CORKBOARD
A mail-order parcel, an airmail letter and the new magazine issue on the bed.
THE MAIL

Devlog

Engineering memos from United Northern Computers
UNC ENG MEMO #003 · 1 Nov 2026

The machine, and four games to break it

Designing the CPU, the assembler and the emulator, then letting four games tell me what was wrong.

READ > Devlog #002 · 1 Nov 2026

Finding the look

Three directions, one winner, and why the window is a real photograph.

READ > UNC ENG MEMO #001 · 23 Aug 2026

Why the UNC exists

I write software with AI agents all day. This is the other thing I want.

READ >

Join the beta

Mac, PC and Linux

UNC 64 is coming to Mac, PC and Linux. Leave your email and you'll get a beta invite when it's ready to play, and the occasional devlog post until then. Unsubscribe any time.

Why this exists

UNC 64 is a passion project by Viljami Kuosmanen, built in evenings and weekends. Everything is built with AI assistance: the emulator, the BASIC, the assembler and the game. The point isn't to learn game programming. It's to relive exploring and learning an 8-bit computer from the 6502 family, and to make the design decisions. The devlog is where that gets written down.

There's no release date and no schedule. Follow along with the newsletter or the RSS feed. A Steam page and a browser playground for the machine come when there's something to play.