Omega Keyboard
January 4, 2022 · View on GitHub
Keyboard for the Omega Home Computer
Introduction
Hardware Documentation
Schematic and PCB Layout
Connectors
J1 - Keyboard Interface
| Pin | Description | Pin | Description |
|---|---|---|---|
| 1 | Output: Column 0 | 2 | Power: +5V |
| 3 | Output: Column 1 | 4 | Input: Row A |
| 5 | Output: Column 2 | 6 | Input: Row B |
| 7 | Output: Column 3 | 8 | Input: Row C |
| 9 | Output: Column 4 | 10 | Input: Row D |
| 11 | Output: Column 5 | 12 | Input: Caps Lock LED |
| 13 | Output: Column 6 | 14 | Input: Kana LED |
| 15 | Output: Column 7 | 16 | Power: GND |
Bill of Materials - Version 1.0
Omega Keyboard project on Mouser.com - View and order all components except of the keycaps set, and the PCB.
| Component type | Reference | Description | Quantity | Possible sources and notes |
|---|---|---|---|---|
| PCB | Omega Keyboard PCB - Version 1.0 | 1 | Refer to the RetroBrew Computers Board Inventory page for ordering information, or order from a PCB manufacturer of your choice using provided Gerber or KiCad files | |
| Integrated Circuit | U1 | 74LS145 Octal D-Type Latch | 1 | Mouser 595-SN74LS145N |
| Integrated Circuit | U2 | 74LS07 Octal Bus Transceiver | 1 | Mouser 595-SN74LS07N |
| LED | D1 | 3 mm, green LED indicator | 1 | Mouser 593-VAOL-3HDE4 |
| LED | D2 | 3 mm, yellow LED indicator | 1 | Mouser 593-VAOL-3HCE4 |
| LED | D3 | 3 mm, red LED indicator | 1 | Mouser 593-VAOL-3HAE4 |
| Diode | D4-6 | 1N4148 | 3 | Mouser 512-1N4148TR |
| Keyboard Switch | SW1-SW64, SW66-SW73 | MX Cherry - Linear | 72 | Mouser 540-MX1A-11NW |
| Keyboard Switch | SW65 | MX Cherry - High Force Linear | 1 | Mouser 540-MX1A-21NW |
| Switch Leveling Kit | SW13, SW49, SW64, SW65, SW73 | Leveling kit for MX 1x2, 1x2.25, 1x2.75 | 5 | Mouser 540-G99-0742 |
| Switch Leveling Kit | SW64 | Leveling kit for MX 1x8 | 1 | Mouser 540-G99-0226 Note: Use one of 540-G99-0742 to build a through hole leveling kit for the spacebar |
| Keycaps | SW1-SW73 | 104 Keycaps kit for Cherry MX Keyboard | 1 | Amazon, for example this one |
| Connector | J1 | 2x8 pin header, right angle, shrouded, 2.54 mm pitch | 1 | Mouser 710-61201621721 or use 2x8 pin female header to plug the keyboard directly to the mainboard using 15 mm standoffs between them: Mouser 200-ESQ10812LD |
| Capacitor | C1, C2 | 0.1 uF, MLCC, 5 mm lead spacing | 2 | Mouser 594-K104K15X7RF53H5 |
| Capacitor | C3 | 10 uF, MLCC, 5 mm lead spacing | 1 | Mouser 810-FG28X5R1E106MR00 |
| Resistor Array | RN1 | 4.7 kohm, bussed, 6 pin SIP | 1 | Mouser 264-4.7K-RC |
| Resistor | R1 - R3 | 470 ohm, through hole | 3 | Mouser 291-470-RC |
Changes
- Version 1.1
- Rename RR1 to RN1
- Keep pull-ups only for buffered COLUMN outputs. Replace RN1 with 6-pin SIP resistor array
- Update schematic to use newer KiCad libraries
- Add project URL and logos to the silk screen
- Version 1.0
- Initial version
Known Issues
- Version 1.0
- Pull-up resistors are not needed on the keyboard COLUMN outputs. They should be placed on the mainboard instead