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Adding 6502 support

A project log for Gigatron TTL microcomputer

Just because! A home computer without microprocessor

Marcel van KervinckMarcel van Kervinck 06/13/2019 at 00:150 Comments

The computer without microprocessor is becoming dual core.

Today it ran its first 6502 program.

All of the 6502 addressing modes are implemented, and a fair amount of instructions as well. The v6502 interpreter runs in place of the standard 16-bits application vCPU. Switching between the two virtual processors vCPU and v6502 is a matter of modifying a zero page variable. The video driver dispatches at the next available scan line, so very lightweight.

More details on the user forum: https://forum.gigatron.io/viewtopic.php?f=4&t=128

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