Apple 1 Reading from SD card

Chris Davis

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Jun 1, 2020, 11:42:47 PM6/1/20

to Altair-Duino

Here's my kit reading a machine language program from an SD card:

https://youtu.be/HWVSzhp4vpc

Loading a BASIC program:

https://youtu.be/etz1Zw0jur0

John Kennedy

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Jun 2, 2020, 1:11:30 AM6/2/20

to Altair-Duino

Great milestone!

Chris Davis

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Jun 3, 2020, 9:49:00 AM6/3/20

to Altair-Duino

Here it is loading a bit faster:

https://youtu.be/nC9FKpVA9AI

Does anyone have an Apple 1 replica with a cassette interface? I'd like to know how the speed of my method of loading compares with the original cassette. Maybe you could run a couple tests for me.

Jim

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May 16, 2021, 6:13:40 PM5/16/21

to OpenAC1

I've been digging through the A1 Integer BASIC and the Woz (and eWoz) monitor reverse engineered source code lately.

I just started looking at the ACI source code. I may be totally missing the mark, but it seems like the ACI ROM code should run and do a save even if there is no ACI hardware present. In other words, if you load the ROM at $C100 (say into even RAM if you're using an emulator) and start it from the monitor, you could issue the command to save a block of memory and it would happily go along doing reads to $C000 (with toggles the flip-flop that creates the tones) without realizing anything was really happening.

I'm still tinkering with being able to try this in an emulator, but if it works like I think it should it would be easy to time how long it takes to record a given size block of memory.