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Mango One

A simple 6502-based computer inspired by the Apple I, implemented in Verilog.

For the 6502 CPU, we use an open-source model created by Arlet Ottens.

The Mango One's memory map is very similar to the Apple I:

Start End Description
$0000 $0FFF RAM
$D010 $D013 6821 PIA (keyboard, terminal)
$FF00 $FFFF Monitor ROM, CPU vectors

The monitor program in ROM, MangoMon, is a custom 256-byte monitor ROM with just a few commands:

Command Function
R aaaa Dump memory at address $aaaa
Enter Dump next 8 bytes
W aaaa bb Write byte $bb at address $aaaa
G aaaa Jump to address $aaaa

You can open this project in 8bitworkshop and try it out!