Programming

• Adding a Basic Stub to a Vic-20 Assembly Language Program

  10 May 2013   Tags: Programming     Retro     Tutorial     Commodore     Vic-20     Assembly    
  To make machine language programs more friendly it is nice to add a basic stub which contains a line with a SYS statement to start the code. This is easy to do on the Vic-20 and the process gives you an insight into how Basic programs are stored in memory. I’ll show you how to do this and h...   Read More
  
  

• Creating a TTY Simulator in Assembly Language on the Vic-20

  4 May 2013   Tags: Programming     Retro     Commodore     Vic-20     Assembly    
  The Vicmon machine language cartridge is an excellent tool for exploring the Vic-20. This article and its associated video will show you how to use it to create a simple program that will change the normal output of a Vic so that it feels a bit like a teletype terminal. This will be done by takin...   Read More
  
  

• Beginning Assembly Programming on the Commodore Vic-20

  16 April 2013   Tags: Programming     Retro     Tutorial     Commodore     Vic-20     Assembly    
  The Commodore Vic-20 is a great machine to learn an assembly language on. It was released in 1981 and was the first computer to sell one million units, which contributes to is popularity today. The machine is well documented, well supported through forums and much of the hardware is plentiful and...   Read More
  
  

• If Only Borland Had Stuck With Turbo Modula-2 For CP/M

  12 March 2013   Tags: Programming     CP/M     Retro    
  I have written previously about why Turbo Pascal is a Great Choice For Programming Under CP/M and now it is time to talk about what could have been. You probably haven’t heard of Turbo Modula-2 for CP/M as it was only on the market for a brief period of time. However, it was a superb produc...   Read More
  
  

• Turbo Pascal: A Great Choice For Programming Under CP/M

  5 March 2013   Tags: Programming     Pascal     CP/M     Retro    
  CP/M was blessed with many programming languages, each with their own strengths and weaknesses. I think that Turbo Pascal stands out from these and I’m not alone. When Turbo Pascal was released in 1983 by Borland, as their first software development application, it was quickly adopted by sc...   Read More
  
  

• xdgbasedir: A Tcl Module to Access the XDG Base Directory Specification

  27 February 2013   Tags: Programming     Tcl/Tk    
  Unix has traditionally lacked a consistent way of storing user specific and system wide configuration and support files. This has lead to a mess of dot files in a user’s home directory and other associated files being all over the file system. The XDG Base Directory Specification describes ...   Read More
  
  

• Compiling a Tcl Script into an Executable

  20 February 2013   Tags: Programming     Tcl/Tk     Tutorial     C    
  Locating Tcl scripts to load from an executable can be awkward if you want to make your program cross-platform. An easier way is to compile a Tcl script directly into the executable and let that script find any other scripts needed. This is particularly relevent as so many programs just use a sin...   Read More
  
  

• Using Dynamically Generated Header Files with CMake

  12 February 2013   Tags: Programming     Tutorial    
  Sometimes it can be useful to dynamically generate header files and include them from a C source file. However, it can be a little difficult getting CMake to recognize when to generate the files and when to recompile the source files that include those headers. What follows is a method to do this...   Read More
  
  

• Embedding an SDL Surface in a Tk Window

  26 June 2012   Tags: Programming     SDL     Tcl/Tk     Tutorial    
  Tk is great, but sometimes it just isn’t fast enough. SDL is fast, but has no support for input dialogs and other GUI conventions. By embedding an SDL surface in a Tk window you get the best of both worlds. Whether you want to use Tk to add a nice GUI to an SDL app or want to access SDL via...   Read More
  
  

• Refactoring: Arm Yourself in the War Against Useless Comments

  26 April 2012   Tags: Programming    
  Comments, comments, everywhere, but are they making your code clearer or just distracting you? Comments are meant to be there to explain code and help you to understand it. However, they are often out of step and therefore can confuse. Think seriously before adding comments; it is often better to...   Read More
  
  

• Dealing Sympathetically with Legacy Code

  20 April 2012   Tags: Programming     Legacy Code     Retro    
  I have often noticed programmers getting worked up about the legacy code they are maintaining. I know it is annoying having to wade through poor code, or worrying about making changes for fear of unexpected side-effects. However, it is important to see the code for what it is and in the context o...   Read More
  
  

• Running 4K FORTRAN on a DEC PDP-8

  14 July 2009   Tags: DEC     Retro     PDP-8     FORTRAN     Programming     Tutorial    
  4K FORTRAN was a subset of FORTRAN II and was the first high-level language available for the DEC PDP-8. It consisted of two parts: the 4K FORTRAN Compiler (nicknamed “Fivetran”) and the 4K FORTRAN Operating System. The compiler was written by Larry Portner and the operating system wa...   Read More
  
  

• An Introduction to Corewar

  30 April 2009   Tags: Programming     Corewar     Programming Games     Retro    
  I remember reading about Corewar roughly 20 years ago and thinking that I will have to have a go at that when I get the time. As often happens in life, things got in the way and I only recently managed to give it a go. I love the challenge of programming and the competitive aspect of this program...   Read More
  
  

• The Smallest Communication Program in the World?

  23 April 2009   Tags: 80x86     DOS     Programming     Retro     Assembly    
  I was going through a backup of my dos machine, taken in 1998, and came across some source code which I haven’t seen for a long time. It was great to see that old code, and I must set-up a machine so that I can run some of it again. In particular I came across an attempt at writing the worl...   Read More
  
  

• Hello, World! in SUBLEQ Assembly

  29 March 2009   Tags: Programming     OISC     SUBLEQ     Assembly    
  After writing a previous article: The SUBLEQ URISC (Ultimate RISC) / OISC (One Instruction Set Computer) Architecture. I was left thinking that I should really have given at least a “hello, world” program as a demonstration. I was then inspired after seeing John Metcalf’s post: ...   Read More
  
  

• An Introduction to Test-Driven Development

  18 March 2009   Tags: Test Driven Development     Debugging     Programming    
  For the past 6 months I have been using Test-Driven Development (TDD) on a new project. It has made such a difference to the quality of my code, that I feel I just have to share it’s benefits with those who may not have heard of it. TDD reverses the normal order of testing as it requires de...   Read More
  
  

• Book Review: The Mythical Man-Month: Essays on Software Engineering by Frederick P. Brooks, Jr.

  26 January 2009   Tags: Book     Programming     Retro     Review    
  This book, written in 1975, offers a fascinating insight into the software engineering process used at that time. The author draws from his experience as project manager for the IBM System/360 and OS/360, and in doing so also sheds light on how they were put together. The 1995 edition, reviewed h...   Read More
  
  

• Writing my First Program to Toggle in to the IMSAI 8080

  5 November 2008   Tags: 8080     IMSAI     Programming     Retro     Assembly    
  I have long been fascinated with entering programs into computers by methods not involving a standard keyboard and monitor. This interest was peeked by my last article: Using the latest z80pack, version 1.17, to emulate an Altair 8800 or IMSAI 8080 using the new graphical FrontPanel. I have there...   Read More
  
  

• Installing the HI-TECH Z80 C Compiler for CP/M

  22 October 2008   Tags: C     CP/M     Programming     Retro     Z80     Tutorial    
  My language of choice is C and I am currently getting more involved with the CP/M operating system. I have therefore decided that it would be nice to have a C compiler working under CP/M. There are a number of options available in the archives, but I have found that HI-TECH are allowing their CP/...   Read More
  
  

• Installing ZDE 1.6, a programmers editor for CP/M

  21 October 2008   Tags: CP/M     Editors     Programming     Retro     Tutorial    
  To do any serious programming under CP/M, the first thing you need is a good programmers editor. There aren’t many in the archives, but I have tried most of them and found ZDE to be the best. It is small, has lots of features, and uses Wordstar commands which are familiar to me and easy to ...   Read More
  
  

• How to share an SSL certificate and still use cookies

  16 September 2008   Tags: PHP     Programming     Security     SSL     Web Development    
  Website hosting companies often provide a shared SSL certificate, but this presents the web designer with the problem of how to use it for a site that uses cookies. I have read many people say that this can’t be done. However, this article will show a simple way of using a shared SSL certif...   Read More
  
  

• Is COBOL really understandable after 14 years?

  8 August 2008   Tags: Programming     Cobol     Retro    
  COBOL has been in the news quite a lot recently and I have been reading that there are still huge amounts of COBOL code running and being written. This led me to wonder why this language was still being used. I therefore decided to look at a few sites about COBOL and see what they said was good a...   Read More