Blog posts and video from Steven as he “COMBS” through the minutia to discover tech, retro-computing, physical computing, gadgets and sci-fi.

retroCombs Playlist

Commodore Plus/4 Series

Commodore Plus/4 Resource Page

This page is an ongoing resource for readers and watchers of my Commodore Plus/4 series. I encourage you to contribute to this project by commenting on YouTube videos or on individual blog posts.

retroCombs Plus/4

Page Contents

Use the handy table of contents below to jump to a section on this page.

Key to Keys

Because the Commodore Plus/4 keyboard is so different from modern keyboards, I devised a modern key nomenclature to identify keystroke combinations as shown in the table below:

Key Description Key Description
Caps Lock F1 Function 1
[C=] Commodore F2 Function 2
Control F3 Function 3
Escape F4 Function 4
Clear/Home F5 Function 5
Insert Delete F6 Function 6
Return F7 Function 7
[R/S] Run/Stop F8 Help
Shift Space
Cursor Up Cursor Down
Cursor Right Cursor Left

Below is a link to each blog post in the series. All Amazon links are affiliate links. Thanks for supporting the blog and the YouTube channel!

Each blog post contains the companion YouTube video and most include links to items or sites. This page captures a collection of all links mentioned.

  1. Commodore Plus/4 User’s Manual, Chapter 0 - Open the Box

    I share my first experience with a Commodore computer (it is not the Plus/4) and then open the box on my Commodore Plus/4 eBay purchase.

  2. Commodore Plus/4 User’s Manual, Chapter 1 - Unpacking and Setting Up

    I open the Commodore Plus/4 manual for the first time and look at Chapter 1: Unpacking and Setting Up. Since the previous episode was an open the box, unpacking is already complete and this episode focuses on setting up the computer. Along the way I share a very cool tip.

  3. Commodore Plus/4 User’s Manual, Chapter 2 - Using the Keyboard and the Screen

    I talk about the keyboard layout, using the keyboard, and then how keyboard combinations affect screen elements. This is really a “hands on” episode!

  4. Commodore Plus/4 User’s Manual, Chapter 3 - Using Software

    I cover each auxiliary storage device in detail; however, I add a modern spin and instead of the original devices; I use a new 264 diagnostic cartridge, a Tapuino, and a Pi1541.

  5. Commodore Plus/4 User’s Manual, Chapter 4 - Getting Started

    It seems like we’ve been getting started over and over, but I guess now we really are since the manual told us so! In this chapter I look at keyboard colors, reverse printing, correcting mistakes, the screen, and even windows. Yes, that’s right, I typed windows. See the blog post and video for more on that topic.

  6. Commodore Plus/4 User’s Manual, Chapter 5 - Numbers and Calculations

    In this chapter, Number and Calculation, I learn how to use the Plus/4 as a calculator in immediate mode, create a function, and learn more about working with numbers in Commodore BASIC 3.5. I even combine some things we learned in previous chapters to amp up our programs. It is a packed chapter and even though I’m no math teacher; I hope I do the concepts justice. This is one chapter where I find the User’s Manual a bit lacking but adequate.

  7. Commodore Plus/4 User’s Manual, Chapter 6 - Beginning BASIC Programming

    In Chapter 6, Beginning BASIC Programming, of the Commodore Plus/4 user’s manual, we begin where everyone should with their Commodore computer; learning the BASIC programming language. In previous chapters we have dabbled with BASIC; however, in this chapter, we dive in and learn the “basic” concepts you need to begin your BASIC programming journey.

  8. Commodore Plus/4 User’s Manual, Chapter 7 - Using Graphics and Color

    Our first significant foray into custom graphics, besides PETSCII, on the Plus/4 begins in this chapter; Using Graphics and Color. The Plus/4 and its sibling, the C16 did not include sprites or other custom chips to enhance graphics; however, it did include a custom BASIC commands not found on the VIC-20 or C64. The extra graphics commands and additional graphics modes make the Plus/4 whole lotta fun if you want to draw on your computer using a command language.

  9. Commodore Plus/4 User’s Manual, Chapter 8 - Making Sound and Music on the Plus/4

    This last chapter in the user’s manual takes us on a musical and noise infused journey through Commodore Basic and the Plus/4 SOUND and VOL commands. The Plus/4 was not capable of the amazing sounds that come from it’s older brother and sister, the Commodore 64 or the 128. Heck, it wasn’t even as capable as the earlier VIC-20; however, with a little effort and creativity, you can put the two channels to use in business applications; the primary market for the Commodore TED series.

Companion Disk Image

As I progress through the user’s manual, I enter and execute the sample programs. The link below is to a .d81.d64 image that below contains every program from each episode. Currently, the image is not complete since we still have several chapters to go.

retroCombs User’s Manual Disk Image - UPDATED AS OF: 2021-02-13

I use the following file name convention to make it easy to locate specific programs:


  • 02C# - where # is the chapter number
  • RCOMBS SCROLL - my self assigned name for the BASIC program which will be immediately identifiable if you follow along.P#` - where # is the page number where the program is first referenced in the user’s manual
  • NAME - my self assigned name for the program

User’s Manual

In the Commodore Plus/4 YouTube series, I work through each chapter of the Plus/4 user’s manual. I’ve scanned each chapter and provide those below. I will post new chapters with each new video.

  1. Front Matter
  2. Chapter 1 - Unpacking and Setting Up
  3. Chapter 2 - Using the Keyboard and the Screen
  4. Chapter 3 - Using Software
  5. Chapter 4 - Getting Started
  6. Chapter 5 - Numbers and Calculations
  7. Chapter 6 - Beginning BASIC Programming
  8. Chapter 7 - Using Graphics and Color
  9. Chapter 8 - Making Sound and Music on the Plus/4

Supplemental Posts

The posts below are helpful for any Commodore 8-bit computer enthusiasts but are also closely associated to this series and supplement the posts found above:

  1. retroCombs: Pi1541 Assembly and First Use

    In this supplemental episode to my Commodore Plus/4 series, I share my experiences assembling the Pi1541 Hat for a Raspberry Pi Zero. In the episode, I solder a pin connector onto the Raspberry Pi Zero, solder and assemble a serial cable with two 6 pin DIN connectors, assemble the whole package, and start up the Pi1541 for a first use.

  2. retroCombs: The Tapuino Project - Build an Arduino powered Commodore Datasette clone

    As part of my Commodore Plus/4 series, chapter three, of the user’s manual, includes a sections on using a Datasette and a disk drive. In a previous post, I built the modern replacement for the disk drive (a Pi1541), now it’s time to create a Datasette replacement called, the Tapuino.

  3. retroCombs: TEDuino: A Modern TED (264) Series Commodore Datasette

    In a previous post, I assembled the modern replacement for the Datasette, the Tapuino. For this project I use another Arduino, in this case the inexpensive Arduino Nano, some easy to source electronic components, and a 3D printer to create a Commodore 264 series inspired Datasette replacement I call, the TEDuino.

    The TEDuino

Plus/4 Resources

Below are links I’ve found to be most beneficial as I work through this series:

  1. Commodore4Ever - Source for Pi1451. Great customer service and feedback.
  2. The Future was 8-bit - Source for parts and used to provide resources for the Tapuino project. U.K. based so allow some time for delivery if in the U.S.
  3. RETRO Innovation - Source for parts used for both the Tapuino and Pi1541 projects.
  4. Plus/4 World - The most incredible source of Plus/4 information and software available. I don’t know how the team does it, but if you have a Commodore C16, Plus/4, or 264, this is the site you must visit.

Disclosure Statement: As an Amazon Affiliate (AA), I earn from qualifying purchases when you use the Amazon links. This sites also uses Google Adsense to display advertisements.