Receive No.1

'Receive No.1' is back on iPhone, three decades later. A tennis game that ran on the PC-9801, written in N88-BASIC (a Japanese vintage 8-bit/16-bit computer's BASIC dialect from the late 80s/early 90s). One hundred lines of code, published in Microcomputer BASIC Magazine (ベーマガ) — a Japanese hobby coding magazine. Now ported to iPhone with the original logic intact. ■ Faithfully the original Physics: the original gravity model, unchanged. Arm collision detection: the same Sin/Cos lookup tables sampled at 22.5° steps. Score handling, ball-fall calculation — everything follows the original BASIC code. Because the math matches, the original behavior comes through: - Serves rise straight up from the court edge and fall back down - The angle and speed of the return are decided by the moment your arm swings through - Touch the ball three times and you lose the rally - Only the server scores points ■ The original feel, nostalgic again Sometimes the ball passes right through your arm. Sometimes you can't return the serve. That's how the math worked back then. Because the original is reproduced faithfully, those quirks come back — and now they feel nostalgic. The same 90s-era precision, running on a modern phone. ■ CPU opponent, finally possible Single-player CPU mode was hard to implement back on PC-9801. Now it's here. - Evolving CPU: a learning AI driven by 20 genes. We ship an "initial CPU" pre-trained for 1500 generations. Train your own and export it as JSON to share. - Watch mode: let CPU vs. CPU rallies play out. Some go on for many exchanges. ■ For you, if… - You once copied program listings out of Microcomputer BASIC Magazine - You played games on PC-9801, PC-8801, MSX, or X68000 - You've touched N88-BASIC - You're into 90s Japanese DIY game culture ■ Free. Ads only on AI parts. The app is fully free. Ads only appear during AI training and CPU vs. CPU watch mode. Modes where a human is playing (vs. CPU, two-player) have no ads at all. We collect no personal data. Everything stays on your device.