Born in the Dutch hacker scene of 1991, the HACKTIC Demon Dialer was a pocket-sized telephony signaling device powered by a Motorola 68HC05 microcontroller. This is its browser-based resurrection — fully interactive with real-time tone synthesis.
Every mode the original hardware supported — now in your browser
Standard Touch-Tone dual frequencies: 697–941 Hz rows × 1209–1633 Hz columns. The universal telephone dialing standard.
Multi-Frequency in-band signaling: 2-of-6 tones from 700–1700 Hz. The legendary frequencies that Captain Crunch discovered.
International R2 MF signaling using 2-of-6 frequencies from 1380–1980 Hz. Used on international trunk circuits.
International trunk signaling standard with 2-of-6 MF tones (700–1700 Hz) plus 2400/2600 Hz supervisory signals.
US payphone coin deposit tones: ACTS (1700+2200 Hz), IPTS (1500+2200 Hz), and non-ACTS (2200 Hz) burst patterns.
2400/2600 Hz supervisory signaling, plus direct access to 2040, 2280, 2500, 3000 Hz and other telephony frequencies.
The Demon Dialer was created by HACKTIC, the legendary Dutch hacker collective, and first published in Hacktic Magazine issues 14/15 (1991).
Powered by a Motorola MC68HC05C8 microcontroller running at 4.194 MHz, it packed an extraordinary amount of telephony knowledge into 8KB of firmware — supporting DTMF, MF, R2, CCITT, Red Box tones, macros, frequency programming, and serial communication.
This browser emulation faithfully reproduces all signaling modes using the Web Audio API with clean 44.1kHz sine wave synthesis.
| Component | Detail |
|---|---|
| CPU | Motorola MC68HC05C8 / MC68HC705C8S (UV erasable) |
| Clock | 4.194304 MHz crystal (÷2 = 2.097 MHz bus) |
| ROM | 8 KB OTP/EPROM |
| RAM | 176 bytes internal |
| Audio | 7-bit R-2R DAC on PORTC (8192 Hz sample rate) |
| Input | 4×3 active-high keypad matrix (PORTB/PORTD) |
| Serial | RS-232 via on-chip SCI (1200–9600 baud) |
| Firmware | v1.31 — 3991 lines of HC05 assembly |
| Modes | DTMF, MF, R2 Fwd/Bwd, C3, C4, C5, Red Box, Special, Tone Slot |
| Features | 30 programmable macros, 12 user frequencies, password lock |