Passing Code Pointers as Data in Amstrad CPC BASIC
One of my secret coding pleasures is passing a function as a parameter to a subroutine. Most modern languages have what’s called ‘first class code’. That means that you can assign the address of a function to a variable, store it in an array, and pass it as a parameter to a function. This enables …. Read More
How Amstrad CPC BASIC Compresses Error Messages
Amstrad CPC BASIC saves a few bytes by using some interesting compression in the way it stores error messages. Let’s take a look at how it works and how much space it saves. Below is the table of error messages. The messages are stored in what I refer to as ASCII7 format – bit 7 …. Read More
Couch to 64k Part 3: Adding a Character LCD Display to our Z80 Breadboard Computer
In the previous part of this series we attached a ROM chip to our Z80 so we can run programs. But running programs is of little use unless our computer has some way to communicate with the outside world. We need input and output (I/O). In this part we’ll discuss how input and output work …. Read More
Couch to 64k Part 2: Adding ROM to Our Breadboard Z80 Computer
In part one of this series we explored the Z80 processor and found out what various pins do. And we explored a few of the Z80s opcodes by manually feeding them into the data pins. But feeding instructions and data in manually is hard work. We need to add some memory so we can feed …. Read More
Understanding the RC2014 512k ROM 512k RAM Board
The One Where I Show How-It-Works And How To ‘Burn’ Data To The ‘ROM’ (If you want the source code without the waffle here’s the repository). I recently upgraded my RC2014 to use the 512K ROM 512K RAM board available on Tindie). Most people use this board to run RomWbW but I have different plans …. Read More