Monochrome CRT displays on CNC machines use TTL (Transistor-Transistor Logic) digital video signals that are fundamentally different from the analog VGA signals expected by most LCD monitors. A TTL-to-VGA converter is the key component that makes monochrome CRT-to-LCD upgrades work.
TTL video uses digital on/off signals (0V or 5V) for each color channel, rather than the continuously variable analog voltages used by VGA. In a monochrome display, there is typically a single video signal (intensity). TTL signals operate at standard logic levels and are easily converted to analog.
The KT819 is our dedicated TTL-to-VGA converter designed for CNC monochrome CRT replacements:
| Aspect | Monochrome (TTL) | Color (Analog RGB) |
|---|---|---|
| Signal type | Digital on/off | Analog continuous |
| Converter needed | KT819 | GBS-8219 or KT809 |
| Common on | 9-inch monochrome CRTs (FANUC, HAAS, Mazak, Mitsubishi) | 12/14-inch color CRTs |