16C450/550 UART module for RCBus systems. This is a basic serial transmission module replacing existing solutions on ACIA, allowing the use of more advanced ICs with built-in FIFO and flow control automation (16C550 or later). The module allows the use of UART chips in DIP40 or PLCC44 packages.
| Position | Description |
|---|---|
| 1-2 | from oscillator |
| 2-3 | from bus |
| Position | Description |
|---|---|
| 1-2 (default) | UART address: 0xA0 |
| 2-3 | UART address: 0xA8 |
| Position | Description |
|---|---|
| 1-3 & 2-4 | Bus: Serial 1 |
| 3-5 & 4-6 | Bus: Serial 2 |
| 1-3 & 2-4 5-7 & 6-8 |
Bus: Serial 1 with CTS/RTS signal |
| Position | Description |
|---|---|
| 1-3 | /IRQ (A or B) |
| add jumper 2-4 for /IRQB | |
| add jumper 4-6 for /IRQA | |
| 3-5 | /INT |
| open | interrupt not use |
| Position | Description |
|---|---|
| open | disable |
| close | enable |
External power supply and USB cannot be used at the same time!
| Position | Description |
|---|---|
| 1-2 | DREQ2 |
| 2-3 | DREQ1 |
| both open | disable |
Connect to USB-to-serial converter.
| Component type | Reference | Description | Quantity |
|---|---|---|---|
| PCB | UART 16C450/550 PCB - Version 2.1 | 1 | |
| Integrated Circuit | U1 or U4 | 16C450 or 16C550 UART, DIP40 or PLCC44 | 1 |
| Integrated Circuit | U2 | 74HCT138 - 3-to-8 line decoder, 16 pin DIP | 1 |
| Integrated Circuit | U3 | 74HCT00 - Quad 2-input NAND gate, 14 pin DIP | 1 |
| Oscillator | X1 | 1.8432 MHz, CMOS oscillator, half can | 1 |
| Diode | D1 | Small signal Schottky diodes BAT46, DO35 | 1 |
| Connector | S1 | 2x40 pin header, 2.54 mm pitch, angle | 1 |
| Connector | P1 | 6 pin header, 2.54 mm pitch, angle | 1 |
| Pin Header | JP1,JP2 | 3 pin header, 2.54 mm pitch | 2 |
| Pin Header | JP3 | 2x4 pin header, 2.54 mm pitch | 1 |
| Pin Header | JP4 | 2x3 pin header, 2.54 mm pitch | 1 |
| Pin Header | JP5 | 3 pin header, 2.54 mm pitch | 1 |
| Capacitor | C1 - C5 | 0.1 uF, 50V, MLCC, 2.5 mm pitch | 5 |
| Resistor | R1 - R4 | 2.2 kohm, 0.25 W, axial | 4 |
| Resistor | R5,R6 | 100 kohm, 0.25 W, axial | 2 |
| IC Socket | U1 or U4 | 40 pin DIP or 44 pin PLCC | 1 |
| IC Socket | U2 | 16 pin DIP | 1 |
| IC Socket | U3 | 14 pin DIP | 1 |
| IC Socket | X1 | 4 pin DIP for oscillator | 1 |
Gerber files prepared for production at JLCPCB
-
Version 2.1
- Initial version
Copyright 2025 Tadeusz Pycio
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) .