Apple 1 EPROM Interface

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Macintosh_nik's picture
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Apple 1 EPROM Interface
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Hi guys! On Apple's birthday I want to share a project with you, I did it for myself but I hope you will like it too.

Apple 1 EPROM Interface (AEI) is maybe the smallest (95x45mm) and easiest cartridge card to assemble, it takes only an hour of my free time and few easily available parts: PCB, 2x22 pin connector as on the main board, 24 pin zif socket, 4 pcs M2732A EPROM and possibility to program it, 0,1uf capacitor. The cost of all parts for me was less than 8$ for one board with four EPROMs.

Such cards are not new, I have seen different variants from other guys, my project is only made in the style of Apple 1 Cassette Interface (ACI) and also allows you to quickly and easily run some additional programs and games in a machine language in addition to Basic.

Apple Computer never produced such a card, but in an alternate reality where the two Steve's never met Mike Markkula and the world never saw the Apple II such a card could theoretically have appeared in 1979. That's when a 2732 EPROM with a capacity of 4kB came on the market, enough to hold Basic. On eBay I saw these vintage EPROMs in a beautiful purple ceramic case with gold-plated legs, it would probably look incredibly cool on my card, but eBay is no longer available to me, I buy everything on aliexpress now.

To make the card work, you have to change the location of the jumpers on the motherboard in the area above 74154. They should now look like this: Z-D, E-S and W-1. This has no effect on the ACI and Apple-1 Audio Board, for the Juke-Box you need to jumper RAM 1000-1FFF to NOT ENABLE! To start, you have to type E000R on the keyboard, and Basic and Worple! will boot instantly, in the case of the other two EPROMs you will see a very nice and clear menu, for which I have to thank the esteemed nippur72. The first EPROM contains the beloved Apple 30th graphic demo (Dave Schmenk), the Mastermind game (Steve Wozniak) and the test program from the Apple-1 manual. The second EPROM contains Memory Test (Mike Willegal) and a couple of fun games: 2048 (Denis Paryshev) and Shut The Box (Jeff Jetton). To run the memory test you must first enter the addresses:

0: 0 5 0 20 for the test of both banks at once

0: 0 4 0 10 for the test of bank X

0: 0 10 0 20 for bank W test,

then you have to enter E000R and select the corresponding digit from the menu (1). Third EPROM with Basic, you can easily try your hand at programming. You can also use this card in tandem with the ACI card to load programs written in Basic. To do this, insert the EPROM with Basic in the zif slot, connect both cards and then do everything as if you were loading programs on machine code, and Basic will load automatically. On the last fourth EPROM there is another new game Jeff Jetton Worple!

This card is not intended to compete with the SD card or Juke-Box from the esteemed p-lab. Those who want more functionality and all the available Apple-1 software should look in the direction of these two cards.

At the link you can download the gerber PCB for ordering, the firmware images and the sticker file. I hope this will be useful to someone.

 

 

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Nice, if the solder bride Y-F

Nice, if the solder bride Y-F gets removed and S gets connected to F this nice PCB should be able to replace the two onboard PROMs.

If no PROMs are installed and only in this case the bride Y-F does not need to be removed.

Keep in mind Wozmon needs to be programmed to the end and not the beginning of the 4K EPROM.

The rest of the Eprom could be filled with Krusader.

With some little modification a 27c64 should be possible too which can hold Integer Basic as well.

 

The Apple I shown in front of the Kremlin is the one populated with eastern europe and USSR replacements parts right?

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Hi natas666!
Thank you! No, I am not a fan of Soviet microchips. A friend of mine built it with Soviet chips, if interested I can find a picture of his board, it looks unusual but it's definitely not my choice.  On my board almost all Signetics chips and some Fairchild and almost all with correct datacodes. Only the processor is Chinese, a proper 6502 processor is not a cheap thing... I have a Newton NTI board, full set of correct TI ic sockets, someday I'll find what I'm missing one way or another and build a "dream replica".
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That ZIF EPROM board is a

That ZIF EPROM board is a really nice idea!

 

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Yes I actually would like to

Yes, I actually would like to see a board with russian chips.

I think this board is also usefull for diagnostics.

 

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Hi softwarejanitor!

Thank you! I just wanted to have another way to load my favorite programs on my replica. Downloading programs through an ACI card is authentic but not very convenient. I have a Juke Box card, it's very handy but one look at it is enough to know it's not from the 70's, not authentic. For me the EPROM card was an acceptable compromise.

 

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Hi natas666!

Here's a thread the author created four years ago here on applefritter - https://www.applefritter.com/content/apple-i-replica-using-ussr-components#comment-

 

In the first post there is a link to google drive with photos, I checked it still works.

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Nice board. And the picture

Nice board.

 

And the picture brings back memories, its been a few years since I have stood in Red Square.

 

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Hi Gary C!

Thank you! As soon as things get better you can come again, fortunately nothing has changed there: crowds of tourists, people are still running somewhere and the line to the Lenin Mausoleum as before starts almost from the monument to Zhukov.

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I'm about a year late, but...

Just now seeing this cool project! Nice work!

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Hi JeffJetton!

Thanks! There are a couple more fresh EPROMs for this project:

 

https://www.applefritter.com/content/couple-games-apple-eprom-interface-card

 

Actually I have to thank you for your cool game Worple! If you have or will have other interesting games for Apple-1, I will gladly add them to this project.

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More games

I am working on a project at the moment that runs on a 6502. It has multiple games on it. When I'm done, it might not be that much work to convert some of them over into Apple 1 versions. We'll see!

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