Apple-1 RAM and ROM expander card

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greatman's picture
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Apple-1 RAM and ROM expander card

I made a Ram expander for my Apple-1 replica. It has a 4K ROM with BASIC burned in and 32K static RAM, 2000h to 9FFFh address space. Memory addressing is performed by a properly programmed 74S188 PROM enabled by a NAND gate. The original 8K dram is set to 000h - 1FFFh.
The expander works perfectly, currently the final PCB is in production.
I'm going to make a demo video on Youtube where I'll post the documentation, along with the ROM and PROM content to burn. It may also be available for sale.

macnoyd's picture
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Anxious to see ...

Always good to see folks with new developments for the old hardware.  Looking forward to it.

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I look forward to your video.

I look forward to your video.

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Any thoughts on price point?

Any thoughts on price point?

greatman's picture
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I did not think about the

I did not think about the exact price, because my goal is not to make money. But it can be around $ 60- $ 70. The documentation will be public so you can do it yourself ...

greatman's picture
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Here's the video.
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