Published August 24, 2021

Pi64

The Pi64 is a Raspberry Pi 400 that thinks it's a Commodore 64.

BeginnerFull instructions provided1 hour4,484

Things used in this project

Hardware components

Raspberry Pi 4 Model B

Story

The Pi64 is a Raspberry Pi 400 that thinks it's a Commodore 64.

I love the retro vibes that the Raspberry Pi 400 gives off. The all-in-one computer-in-a-keyboard design makes me feel like I'm working with a computer from my childhood. The only problem I have is that when I look up from the keyboard, it's just another modern(-ish) computer running Linux. I set out to fix that with the Pi64.

Inspired by the Commodore 64, the Pi64 boots into a C64-themed bash shell in text mode. No X Server is involved. It is not a C64 emulator, it is Raspberry Pi OS, so you can get real work done; it just extends the Pi 400's retro feel to the screen.

How It Works

The following assumes that you are running Raspberry Pi OS (although I expect that many Linux distributions would work). As a prerequisite, you'll need to install tmux, e.g.:

sudo apt-get install tmux

Then you'll need to append the following color codes to your ~/.bashrc file:

if [ "$TERM" = "linux" ]; then
    echo -en "\e]P0483AAA" # DARK BLUE 
    echo -en "\e]P1867ADE" # LIGHT BLUE
    echo -en "\e]P2867ADE" # LIGHT BLUE
    echo -en "\e]P3867ADE" # LIGHT BLUE
    echo -en "\e]P4867ADE" # LIGHT BLUE
    echo -en "\e]P5867ADE" # LIGHT BLUE
    echo -en "\e]P6867ADE" # LIGHT BLUE
    echo -en "\e]P7867ADE" # LIGHT BLUE
    echo -en "\e]P8867ADE" # LIGHT BLUE
    echo -en "\e]P9867ADE" # LIGHT BLUE
    echo -en "\e]PA867ADE" # LIGHT BLUE
    echo -en "\e]PB867ADE" # LIGHT BLUE
    echo -en "\e]PC867ADE" # LIGHT BLUE
    echo -en "\e]PD867ADE" # LIGHT BLUE
    echo -en "\e]PE867ADE" # LIGHT BLUE
    echo -en "\e]PF867ADE" # LIGHT BLUE
    clear
fi

This replaces the standard tty colors with the RGB values for C64 light and dark blue. Next, to set the login banner, append the following to ~/.bashrc:

mem_total=$(cat /proc/meminfo | grep "MemTotal" | tr -s ' ' | cut -d" " -f2)
mem_total_unit=$(cat /proc/meminfo | grep "MemTotal" | tr -s ' ' | cut -d" " -f3)
mem_free=$(cat /proc/meminfo | grep "MemFree" | tr -s ' ' | cut -d" " -f2)
mem_free_unit=$(cat /proc/meminfo | grep "MemFree" | tr -s ' ' | cut -d" " -f3)

mem_total_unit=${mem_total_unit^^}
mem_free_unit=${mem_free_unit^^}

center() {
  termwidth=224
  padding="$(printf '%0.1s' ' '{1..500})"
  printf '%*.*s %s %*.*s\n' 0 "$(((termwidth-2-${#1})/2))" "$padding" "$1" 0 "$(((termwidth-1-${#1})/2))" "$padding"
}

center "**** PI64 RASPBERRY PI OS ****"
echo ""
center "$mem_total $mem_total_unit RAM SYSTEM  $mem_free $mem_free_unit FREE"
echo ""
echo "READY."
echo ""

With that one-time setup in place, the Pi64 prompt can be launched by running the script:

./pi64.sh

It isn't super easy to get a tty to do this sort of thing, so it took a hacky sort of hack to get it working. A highly-tweaked tmux session is created (see tmux.sh), with 7 panes laid out something like this:

--------------------
--       p0       --
--------------------
-- p1 -- p2 -- p3 --
--------------------
-- p4 -- p5 -- p6 --
--------------------

Pane p2 in the center is the active display area, so a bash prompt is started there, and it is set as the active pane. All of the other panes run a bash script that hides the prompt and makes them look like a solid border, in C64 light blue. Borders between tmux panes are styled, and the status bar removed, to complete the effect.

The end result is pretty fantastic, if I do say so myself. It looks and feels like working on a C64, but with all the conveniences of a modern Linux distribution.