Known as “Dr. Beep”, Johan is well known for his many small programs that push the limits of the Sinclair ZX81.
Johan Koelman
Articles (2)
| Title | Author(s) | Publication | Date |
|---|---|---|---|
| 1K Othello Not too long ago I discovered the Dr. Beep did a 1K version of Othello. I thought I would look... | Tim Swenson | ZXzine | January 2025 |
| Classic Arcade Games from Dr. Beep Dr. Beep (Johan Koelman) has released 1K versions of two classic arcade games, Asteroids and Missile Command. These games are... | Tim Swenson | ZXzine | July 2025 |