SNES LoROM Multi Cart (THT - Rev.B V2) - Tested!
author: ziggy587
2 layer board of 4.01 x 1.45 inches (101.9 x 36.9 mm)
Uploaded:
May 13, 2021
Shared:
May 13, 2021
Total Price:
$29.10
This board has been tested and found to work as expected.
There is a surface mount version available as well.
Description
You can use this PCB as a basic LoROM board with a max ROM size of 8Mib. Or, with the 74LS161 installed, you can use this board as a 2-in-1 or 4-in-1 multi cart. Games are switched by hitting the console reset button. This board was designed to use 27C080/27C801, but you can use other memory with a compatible pinout such as 27C040/27C401.
Jumper Settings
Jumpers JP1 and JP2 will have to be set depending on how many games will be on the cart and what size memory you are using. View the tables below to see how to set the jumpers when using 29C080 or 29C040 memory.
For example, “1-2” means to short pads 1 and 2.
| (Memory = 29C080) | JP1 | JP2 |
|---|---|---|
| ONE Game | 1-2 | 1-2 |
| TWO Games | 2-3 | 1-2 |
| FOUR Games | 2-3 | 2-3 |
| (Memory = 29C040) | JP1 | JP2 |
|---|---|---|
| ONE Game | Unused | 1-2 |
| TWO Games | Unused | 2-3 |
JP1 controls ROM A19 and JP2 controls ROM A18. Other configurations can be made by using jumper wires.
Note on using 27C040 memory: 27C040 does not have an A19 address line, which is why JP1 is unused in this case. The highest address line on 27C040 is A18. If you close close the 2-3 pads on JP2 that will allow for a 2-in-1 (two 2Mib games), however, the games will be switched every other reset. If you want to use 27C040 and have the games switched on every reset, solder a bodge wire from JP1 pad 3 to JP2 pad 2. This will connect the highest address of 27C040 (A18) to the first output of the 161.
BOM
| Part | Value |
|---|---|
| IC1 | 27C080 (or compatible pinout) |
| IC2 | 74LS161 |
| IC3 | 12F629 (Super CIC) |
| C1 | 22 µF electrolytic |
| C2 / C3 / C4 | 0.1µF ceramic |
| LED1 | Your Choice |
| R1 | Depends on LED1 |
| R2 | 2.5 k ohm |
Notes
Use the SuperCIC key, found here. If your SNES is modified to deactivate the lockout chip, then you can omit this part if you wish. If you do not use the Super CIC, then omit C4 and R2. R2 is a pull-up resistor, the value isn’t crucial, anything 2.5 k (2k5) or higher should be fine.
If you are only installing one game on the cart, then you do not need the 74LS161 or C3. In this case, set both jumpers to the 1-2 position.
R1 value is determined by the LED that you use. Digi-Key has a calculator to make it easy. If you do not use an LED than omit R1.
JP3 controls the LED. If you bridge the left and middle pads, the PIC will control the LED. If you bridge the right and middle pads, the LED will have constant power. If you are not using using an LED then you can ignore JP3.
JP`1 and JP2 jumper pads are spaced for 0 ohm 0805 resistors, but you can simply use a blob of solder instead. Alternatively, you can use a bit of wire or the trimmed legs from C1.
DO NOT order this board with OSH Park’s standard 1.6mm board thickness. 1.6mm is too thick and you wont be able to insert the cart in the console (you will likely damage your cart slot if you somehow manage). You can get 0.8mm from OSH Park, and it should work fine, but please keep in mind that this is thinner than official SNES carts and may not always work properly. The correct board thickness for SNES carts should be 1.2mm, which sadly OSH Park does not currently offer.
Version History
Rev.B V2
• Added JP3 (select if LED is controlled by PIC or has constant power). • Added more ground plane area to front side. • Added silkscreen edge connector identifiers.
Rev.B
• Moved IC2 and C3 further from edge connector; amended related traces. • Improved various trace and via placements; reduced via count. • Moved location of C2; adjusted GND and +5V planes. • Fixed JP2 mislabeled silkscreen.
This board has been tested and found to work as expected.
There is a surface mount version available as well.
Description
You can use this PCB as a basic LoROM board with a max ROM size of 8Mib. Or, with the 74LS161 installed, you can use this board as a 2-in-1 or 4-in-1 multi cart. Games are switched by hitting the console reset button. This board was designed to use 27C080/27C801, but you can use other memory with a compatible pinout such as 27C040/27C401.
Jumper Settings
Jumpers JP1 and JP2 will have to be set depending on how many games will be on the cart and what size memory you are using. View the tables below to see how to set the jumpers when using 29C080 or 29C040 memory.
For example, “1-2” means to short pads 1 and 2.
| (Memory = 29C080) | JP1 | JP2 |
|---|---|---|
| ONE Game | 1-2 | 1-2 |
| TWO Games | 2-3 | 1-2 |
| FOUR Games | 2-3 | 2-3 |
| (Memory = 29C040) | JP1 | JP2 |
|---|---|---|
| ONE Game | Unused | 1-2 |
| TWO Games | Unused | 2-3 |
JP1 controls ROM A19 and JP2 controls ROM A18. Other configurations can be made by using jumper wires.
Note on using 27C040 memory: 27C040 does not have an A19 address line, which is why JP1 is unused in this case. The highest address line on 27C040 is A18. If you close close the 2-3 pads on JP2 that will allow for a 2-in-1 (two 2Mib games), however, the games will be switched every other reset. If you want to use 27C040 and have the games switched on every reset, solder a bodge wire from JP1 pad 3 to JP2 pad 2. This will connect the highest address of 27C040 (A18) to the first output of the 161.
BOM
| Part | Value |
|---|---|
| IC1 | 27C080 (or compatible pinout) |
| IC2 | 74LS161 |
| IC3 | 12F629 (Super CIC) |
| C1 | 22 µF electrolytic |
| C2 / C3 / C4 | 0.1µF ceramic |
| LED1 | Your Choice |
| R1 | Depends on LED1 |
| R2 | 2.5 k ohm |
Notes
Use the SuperCIC key, found here. If your SNES is modified to deactivate the lockout chip, then you can omit this part if you wish. If you do not use the Super CIC, then omit C4 and R2. R2 is a pull-up resistor, the value isn’t crucial, anything 2.5 k (2k5) or higher should be fine.
If you are only installing one game on the cart, then you do not need the 74LS161 or C3. In this case, set both jumpers to the 1-2 position.
R1 value is determined by the LED that you use. Digi-Key has a calculator to make it easy. If you do not use an LED than omit R1.
JP3 controls the LED. If you bridge the left and middle pads, the PIC will control the LED. If you bridge the right and middle pads, the LED will have constant power. If you are not using using an LED then you can ignore JP3.
JP`1 and JP2 jumper pads are spaced for 0 ohm 0805 resistors, but you can simply use a blob of solder instead. Alternatively, you can use a bit of wire or the trimmed legs from C1.
DO NOT order this board with OSH Park’s standard 1.6mm board thickness. 1.6mm is too thick and you wont be able to insert the cart in the console (you will likely damage your cart slot if you somehow manage). You can get 0.8mm from OSH Park, and it should work fine, but please keep in mind that this is thinner than official SNES carts and may not always work properly. The correct board thickness for SNES carts should be 1.2mm, which sadly OSH Park does not currently offer.
Version History
Rev.B V2
• Added JP3 (select if LED is controlled by PIC or has constant power). • Added more ground plane area to front side. • Added silkscreen edge connector identifiers.
Rev.B
• Moved IC2 and C3 further from edge connector; amended related traces. • Improved various trace and via placements; reduced via count. • Moved location of C2; adjusted GND and +5V planes. • Fixed JP2 mislabeled silkscreen.
