Starting on Commodore-64, generally called C64 (MOS 6510 that is a modified version of 6502, will use 65xx here) assembly on Linux. This 8-bit microprocessor is relatively limited and simple, as Z80 microprocessor, and used on several popular platforms, including Commodore PET/VIC20, Apple][, BBC, Oric 1/Atmos/Telestrat, Atari 400/800/5200/XL/Lynx, NES and SNES or PC Engine/TurboGraphix. The power of the most interesing of these computers are in association with their audio, graphics and video co-processors.
This document, is based on the usage of generaly available and FLOSS, xa assembler, xda65 debugger and VICE emulator, on GNU/Linux platforms.
This picture of "A Mirror of Time" ("Зеркало времени", 1976) animation by Vladimir Tarasov looks a lot like "Q.bert" video game (Warren Davis and Jeff Lee for Atari and Gottlieb, 1982)
This page is about retrocomputing, see also Fantasy Console for virtual neo-retro computers ^^.
This page is about RISC-V emulators, simulators, available distributions and simple and cheap solution to have displayed output
There are a lot of possibilities in this, inluding, for hardware RISC−V display, some LCD screen, HDMI output with closed driver or open driver, with often limited GPU support (work in progress). There are some FGPA based solution with open sources solution.