drop in replacement for Atari 7800 game ROMs DIP-28 for Atari C024926 or CO24926 PCBs. So if you game died but you want to reuse the original PCB to fix your cartridge. The PCB will slot in the PINs on the PCB an can be used for 32kB-ROMs.
To order the latest version either use KiCad or use release zip from GitHub. To generate the Gerber files yourself, open microcade.kicad_pcb in KiCad. Use Fabrication Output > Gerber and select an output folder and agree with Plot with the default configruation. Also use Fabrication Output > Drill Files than select the same output folder and agree with Generate Drill File.
- enter length/width (36.4 x 18 mm)
- 2 layers
- 0.8mm thickness (my recommendation, other is possible too)
- FR4
- TG 150-160
- 6/6mil Min Tracking
- 0.3mm Hole Size
- Solder Mask - any is fine
- Silkscreen - any is fine
- No Edge Connector
- Finish - any is fine but would suggest HASL
- Tending Vias
- 1oz Finish Copper
Upload a zip containing the above generated files or use the release zip. Currently the price for 5 boards should be 5$.
Use your IC burner to program your dump back on the EPROM. Be aware to burn data without any headers. If you want to program the EEPROM after soldering set both Jumpers JP1 and 2 to "Prg" and wire your burner by crossing pin 1 and 27. See below:
| Burner Pins | C024926-Adapter | header pin | C024926 pin description |
|---|---|---|---|
| 27 | 1 | J1 1 | Write Enabled (WE) |
| 2 | 2 | J1 2 | A12 |
| 3 | 3 | J1 3 | A7 |
| 4 | 4 | J1 4 | A6 |
| 5 | 5 | J1 5 | A5 |
| 6 | 6 | J1 6 | A4 |
| 7 | 7 | J1 7 | A3 |
| 8 | 8 | J1 8 | A2 |
| 9 | 9 | J1 9 | A1 |
| 10 | 10 | J1 10 | A0 |
| 11 | 11 | J1 11 | I/O0 |
| 12 | 12 | J1 12 | I/O1 |
| 13 | 13 | J1 13 | I/O2 |
| 14 | 14 | J1 14 | GND |
| 15 | 15 | J2 14 | I/O3 |
| 16 | 16 | J2 13 | I/O4 |
| 17 | 17 | J2 12 | I/O5 |
| 18 | 18 | J2 11 | I/O6 |
| 19 | 19 | J2 10 | I/O7 |
| 20 | 20 | J2 9 | Chip Enabled (CE) |
| 21 | 21 | J2 8 | A10 |
| 22 | 22 | J2 7 | Output Enabled (OE) |
| 23 | 23 | J2 6 | A11 |
| 24 | 24 | J2 5 | A9 |
| 25 | 25 | J2 4 | A8 |
| 26 | 26 | J2 3 | A13 |
| 1 | 27 | J2 2 | A14 |
| 28 | 28 | J2 1 | VCC |
To finish the board two ICs and 2.54mm headers are required. Optional are two 1.27mm headers with shunts. This is needed if eeprom should be programmed soldered in.
| Reference | Part | Amount | Description |
|---|---|---|---|
| U1 | Atmel/Microchip AT28C256-15SU | 1 | 256Kbit parallel EEPROM |
| U2 | Diodes 74AHCT1G04SE-7 | 1 | inverter SOT353 |
| J1, J2 | Würth 61301411121 | 2 | 14pol 2.54mm header |
| JP1, JP2 | Sullins GRPB031VWVN-RC | 2 | optional, 3pol 1.27mm header |
| JP1, JP2 | Harwin M50-1900005 | 2 | optional, 1.27mm shunt |
if jumper isn't used please bridge pin 1 and 2 "Use", see picture above.
- Use: Default, if the adapter is used in the cartridge
- Prg: If the EEPROM should be programmed see chapter "Programm the EEPROM"