Bedroom Coder — It is 1987. A magazine arrives every month.

Your bedroom in 1987

Your parents just bought you a Phantom 64. It sits under the TV on your desk, next to a stack of cassettes.

You spend the night in your room, program on the machine's own display, read something held to the light: a magazine, a letter, a parcel, a printout.

Your moonlit bedroom at night. Your Phantom 64 glows on the desk, the latest issue of Phantom Monthly beside it. The telephone rings. It's September 1987, and you're already making a name for yourself. — Night is for coding. The machine is awake.

A magazine every month

Each issue lands on the desk with a thump: type-in listings, columnists with opinions, readers' letters, and the monthly programming compos.

September's issue promises to teach "the machine to count". Are you finally learning how to loop?

Phantom Monthly magazine cover, Issue 3, September 1987: a pixel-art heap of cassette tapes in green, headline '50 test tapes. One winner.' — Issue 3 — September 1987 — 60p

The machine is real

The Phantom 64 never existed, but in the game it's absolutely real. Under the fiction is a complete 8-bit machine with a real instruction set, real cycle counts, registers... and real consequences, too.

Every brief teaches you something new about it, then asks you to use it. This article is asking you to fix Phasmo, the ghost mascot, in four cells. You need two simple swaps, but it's not as easy as it looks.

A magazine article page: Competition 9, 'Phasmo, Inside Out', with a purple illustration of the ghost mascot mirrored across raster bars. — Four right cells. Not one of them in the right place.

And the assembly is real assembly

The Phantom 64 was designed backwards from the machines that really existed, such as the C64, the Spectrum, the NES and the Amiga.

Here, eight instructions change the border colour faster than the beam can draw it, creating raster bars: it's exactly how the demos of the era did it, on real hardware.

In your quest, you'll learn to juggle screen memory, border register, interrupts, and do much more sophisticated magic. All by solving puzzles.

The code editor with a syntax-coloured assembly listing: BORDER and SCREEN defined with EQU, a write routine using LDIR to copy the word RASTER into screen memory, then a loop that stores the accumulator into the border register, increments it and jumps back forever. — Eight instructions, and no BRK.

The Phantom 64 screen running that program: the border has exploded into hundreds of horizontal stripes in every colour of the palette, framing a black screen with the word RASTER! in the middle. — And this is what they do.

The compos are judged

Send in your entry. The judges score it on the only things that matter: how many opcodes you used, and how many cycles you burned.

Then the standings are printed. You see exactly who you beat... and who beat you. Climb the table, month by month, until your name starts turning up at the top.

Some players seem like magicians, pulling off tricks you wouldn't have thought possible.

But there’s always a way. Their technique might be explained a few issues down the line. Then you can come back, put what you've learned to work, and take your place back.

The verdict slip: ENTRY ACCEPTED for Competition 9, all 5 runs passed clean, with the full compo standings — YOU highlighted at rank 4 of 11, level with Doyle, prize 10 credits. — Rank 4 of 11 — level with Doyle. For now.

Then spend what you win

Placing in a compo pays, and the catalogue at the back of every issue is where the credits go: a joystick, a thermal printer, sound chips, expansion cards that hand the machine powers it didn't have in the box.

Order one and it turns up the next morning, in a parcel you open yourself. New hardware opens compos that were closed to you, brings specialist magazines through the letterbox, and puts jobs on the phone that nobody would have offered you last month.