Every subgroup has its own terms people in the know expect everyone to know. - Everyone knows that … right?

In the wiki is a function active to show a short explanation for certain terms, like what you get when you write C64. - To modify or add those contact Walter.

This page is to try to give some information about terminology used in the Commodore and retro computer community.

• TAP — Raw Tape Image
  • A byte‑accurate recording of the actual magnetic pulses on a Commodore cassette tape.
• PRG — Single Program File
  • A raw C64 program as it appears in RAM, with a 2‑byte load address at the start.
  • Key traits:
    • Contains one program or data block.
    • Loads instantly in emulators or SD2IEC.
• D64 — Disk Image (1541 floppy)
  • What it is:
    • A full 170 KB image of a 5.25“ 1541 disk, including directory, sectors, BAM, and filesystem.
  • Key traits:
    • Can contain multiple PRGs, data files, and custom loaders
• G64
  • Which is a d64 with additional data to represent low level floppy info. Used for disks with disk based copy protection.
• CRT — Cartridge Image (ROM dump) & T64 — Tape Container (simplified tape image)
  • What it is:
    • A virtual tape file that stores one or more PRGs, but not the real pulse‑timing of a tape.
  • Key traits:
    • Contains a directory of PRGs extracted from a tape.
    • Does not preserve turbo loaders or custom tape protection.
    • Loads much faster than a real tape because it skips the pulse‑level detail.

A RAM Expansion Unit is a hardware device that increases the amount of RAM available to a computer. The C64U has this functionality build in and can be enabled in the menu.

The 8-Bit GUY explains how the REU works on the classic C64

Border removal exploits VIC-II behavior when $D011 bit 4 is cleared at specific raster lines. This lets demos display sprites and graphics in the border area.