Retroleum
Last updated: 28 May 2007 - 21:01
Retroleum - "Phil's techie type website." An excellent resource for retro computing (Z80) type info.
Highlights include some useful stuff on TV timings, an 8 bit IDE interface for the Z80 and an impressive graphics system.
Developing an Architecture
Last updated: 08 May 2007 - 21:09
It's been a while since I thought up this project now, and it's heading for a shelf as fast as it's vestigial legs will carry it. I blame this rapid attempt at mothballing on a lack of practical progress while I'm at Uni with no Z80 chips in sight. I have however been thinking about the project a bit and come up with some basic ideas for the architecture.
Firstly, I've decided that instead of the normal idea of holding the operating system on a ROM chip that's used in most Z80 systems, I want to set it up something more like a conventional PC with a boot ROM containing the system BIOS (Basic Input-Output System) which causes the processor to boot from the IDE bus. In my design this is going to be a small compact flash card.
One advantage of this is that it should allow advanced functionality such as being able to edit a version of the operating system kernel on the device itself, reboot, test the new kernel by selecting it from a boot loader menu, if it fails, go back to the f
Beginnings...
Last updated: 20 Apr 2007 - 20:37
In the beginning was the Amstrad NC100.
At one point during the Easter holiday I had the sudden urge to get out my old Z80 based laptop, an Amstrad NC100. Fiddling with it for a little while, I decided it was under-utilising the hardware due to the very restrictive operating system. It does have BBC basic built in, allowing the user to easily write programs, however BASIC isn't a very powerful language (quick to code I'll admit, but not powerful), and the programming was slow. It also left you having to start BASIC, load a program into memory then run it every time you wanted to use one. Clearly this didn't make for an enticing environment to develop.
I then had the idea of writing a new ROM for the device. If you look at the back of an NC100 there's a little panel that comes off with just one screw, revealing a standard 2Mbit ROM. "Easy", I thought, all I need to do is replace that with a memory chip that I've programmed, and away we go. I had an 8KB Ferric RAM (a type of non-vo
Memory Tool
Last updated: 20 Apr 2007 - 16:45
Introduction In some ways a Z80 processors program storage is easier to get at than modern flash based micro-controllers. However, modern micro-controllers usually have suitable software available for modern computers.