Flow Control in Commodore BASIC

I’ve recently discovered a tweet that showed a Commodore 64C complete with green monitor and 1541-II drive, heavily dust covered, but still working and being used in a Polish Auto Shop. The picture itself was fascinating enough, but I’ve also discovered that it was a screen grab from a video – which I’m including here ... Read more

In this screencast I’ll show you how to write your own INPUT routine in Commodore BASIC. This comes in handy when you want to reject certain keys from being used when asking users for keyboard input. In my example I’m going to allow all alpha characters (A-Z), as well as SPACE, RETURN and the DELETE ... Read more

In this episode I’ll show you how to create the iconic flashing borders on Commodore machines. Back in the day, when the system was loading, this was a nice way to indicate that the computer is busy doing something rather than being dead. I’ll show you the principle both in BASIC and in Machine Language ... Read more

In this episode I’ll demonstrate how to use programmatic loops in Commodore BASIC. I’ll show you how to use the FOR/NEXT loop (available in all versions of Commodore BASIC), as well as the DO/WHILE loops (available on the Plus/4 and C128). Enjoy!

In this episode I’ll explain the concept of Flow Control in Commodore BASIC. It’s kind of a video update of a post I did a while ago. In essence, it means that we can tell the programme to take a different route in the code depending on a condition that’s met. We’ll explore the IF/THEN ... Read more

Did you know you can run Commodore BASIC v2 on your Mac and Linux systems as a scripting language? It’s true – thanks to the marvellous efforts of Michael Steil and James Abbatiello. They’ve adapted the original BASIC v2 as featured on the VIC-20 and C64 with additional routines so that it works natively on ... Read more

The Commodore 128 has a built-in machine language monitor which makes it ideal for ML development. However, most (or pretty much all) documentation on this subject is geared towards the Commodore 64, making it slightly difficult to get a head start in writing ML code for the 128. Before I forget how to do it, ... Read more

In this episode I’m adding statistics support to my previous lottery generator on the Commodore 64. I’ll add an array that is updated if my supplied numbers have been matched, and how many times over how many draws this has happened. I’ll also add an option to pause the programme and display the statistics before ... Read more

In this episode I’m amending my previous lottery number generator to take six lucky numbers from the user to match against the randomly drawn numbers from the Commodore 64. This will allow us to compare what the computer has drawn to the user’s input, as well as keep drawing numbers until the user input comes ... Read more

In this episode I’ll show you three ways to take user input from the keyboard in Commodore BASIC. The INPUT and GET commands work on all systems, while the GETKEY command only works on the Plus/4 and C128. I’ll demonstrate how to use all of them. This will come in handy for our little lottery ... Read more