Coding Archives

Notes on how to get things done in various programming languages.

How to print numbers as columns in Commodore BASIC

In this episode I’m demonstrating how to print numbers in evenly spaced columns in Commodore BASIC.

On the C128 and the Plus/4 we can use a nifty little function called PRINT USING for this, with which we can format the output of any printed text or variable.

On the C64 and VIC-20 that function doesn’t exist, so we’ll have to convert a numeric value into a string (using the STR$ function), and then determine how long our string is. Following that we’ll have to manually pad our string value with as many spaces as are required.

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How to build a Word Splitter on the C64 in Commodore BASIC

In this episode I’m demonstrating how to build a word splitter on the Commodore 64. We’ll use string functions to parse a sentence and split each word off into an array of words so that they can be analysed later (for example, as part of an adventure game). Here’s the code I’m building: 20 input … Read more

How to build a time of day clock on the Commodore 64

In this video I’ll demonstrate how to build a simple clock on the C64. We’ll go through this process step by step, including the built-in TI and TI$ variables, string formatting with LEFT$, RIGHT$ and MID$, as well as screen formatting. Here’s the code I’m writing – works in Commodore BASIC v2 and above: 5 … Read more

How to create random YouTube URLs in Commodore BASIC v2

In this episode I’ll demonstrate how to create those seemingly random YouTube Video IDs using a Commodore 64. Here’s the code I’m writing – works in BASIC v2 and above: 10 print chr$(14) 20 gosub 100:x=rnd(-ti):cn=1 30 a$=”” 40 for i=1 to 11 50 rn=int(rnd(0)*62)+1 60 a$=a$+yt$(rn) 70 next 80 print:print cn;” : “;a$ 85 … Read more

How to use Xcode for C and C++ development

Not only is Xcode an excellent IDE for iOS and macOS apps in both Swift and Objective-C; it does just as fine a job for regular C and C++ code. This includes all the features we know and love, such as code completion, version control, and all the rest of it.

Let’s see how to use Xcode 8.3 for C and C++ development.

A Chinese Version of this article can be found here.

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