LT6502: A 6502-based homebrew laptop

Re:LT6502: A 6502-based homebrew laptop by cbm-vic-20 on Monday February 16, 2026 @09:43AM (#47035606)

My alternate reality "one of these days" projects is to have a RISC-V RV32E core on a small FPGA (or even emulated by a different SOC) that sits on a 40- or 64-pin DIP carrier board, ready to be plugged into a breadboard. You could create a Ben Eater-style small computer around this, with RAM, a UART, maybe something like the VERA board from the Commander X16...

It would probably need a decent memory controller, since it wouldn't be able to dedicate 32 pins for a data bus, loads and stores would need to be done wither 8 or 16 bits at a time, depending on how many pins you want to use for that..

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Re:LT6502: A 6502-based homebrew laptop by LeFantome on Monday February 16, 2026 @12:33PM (#47037761)

The really cool thing about RISC-V is that you can design your own core and get full access to a massive software ecosystem.

All you need is RV32I.

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Re:LT6502: A 6502-based homebrew laptop by erwan577 on Monday February 16, 2026 @01:08PM (#47038166)

Have you thought about building a RISC-V “fantasy computer” core for the MiSTer FPGA platform? https://github.com/MiSTer-devel/Wiki_MiSTer/wiki

From a software-complexity standpoint, something like 64 MiB of RAM possibly even 32 MiB for a single-tasking system seems sufficient.

Projects such as PC/GEOS show that a full GUI OS written largely in assembly can live comfortably within just a few MiB: https://github.com/bluewaysw/pcgeos

At this point, re-targeting the stack to RISC-V is mostly an engineering effort rather than a research problem - small AI coding assistants could likely handle much of the porting work over a few months.

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