-----update 01.01.2024------

Backplane Solder kit is available now!

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Find out more at zeal8bit.com.

Do you have the Zeal 8-bit computer and an extension board? Do you need to connect more than a single extension board?

Then the Zeal 8-bit computer backplane is for you! This board lets you extend Zeal 8-bit computer extension port from one to four. you will then be able to connect more PCBs to it, or even probe the signals that are transiting on the bus while an extension is connected thanks to the standard 2.54mm ports.

What is included?

This product includes a pre-assembled and pre-tested Zeal 8-bit backplane. The exhaustive list of components is:

• The Zeal backplane PCB
• A standard 2.54mm 2x25 pin headers at a 90 degrees angle
• Four standard 2.54mm 2x25 pin sockets

What is NOT included?

The Zeal 8-bit computer and the Zeal Gameboy cartridge adapter are not included in the package. You can buy Zeal 8-bit Computer, Zeal 8-bit Gameboy Adpater on Tindie as well.

What about memory mapping and chip select signals?

The backplane itself doesn't present any active component, it doesn't do logic decoding, nor generate chip select signals. As such, the chip selects signals must be generated on the extension boards themselves.

The four ports are therefore interchangeable, plugging an extension board in the first port will have the same effect as plugging it in the second, third or fourth port.

Then, how to plug multiple extensions of the same type?

If you need to plug two identic extensions, you will need to make sure they are not mapped to the same physical address. Since the logic decoding in done on the extension themselves, you may need to reprogram one of the on-board PLD (Programmable Logic Device) to make sure there is not conflict.

For example, if two Gameboy adapters need to be plugged at the same time on the backplane, make sure that the physical addresses they are both mapped to are NOT the same. For example, the PLD of the first adapter can be programmed to be mapped at physical address space 0x3f0000, while the second can be programmed to be mapped at address 0x3e0000.

Support, questions and community

Feel free to join the Zeal 8-bit community to get support, to propose some ideas, to help with the software or simply to discuss with people passionate about retro-computing and Zeal 8-bit Computer.

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