Dec 20, 2018
Today's drone mischief at Gatwick Airport represents a unique problem. I'm going to argue that the question of how bad actors can be prevented from causing trouble with drones poses an existential threat to open code.
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Jan 2, 2016
I recently got my copy of RISC OS Pico, and the very first thing that I wanted to try was running some software from the BBC Welcome Disc. Now, my favourite item on there was a game called Yellow River Kingdom. Here's how to get it running on RiscOS Pico.
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Oct 3, 2013
Well, I've had a frustrating weekend! The EEPROM programmer which I bought from China turned out to be a load of rubbish, so I've sent it back and I'm building my own EEPROM programmer with an Arduino Uno. I'm also taking the opportunity of the time it'll take to get that working to get some new kit in. I'm still sticking with the Z80 for the time being, I don't want the additional trouble of wiring in the 6809 for the moment. Read more for component list and the first program written for the COLLIER-1!
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Feb 9, 2013
So! This morning, I built a clock circuit, and wired it across to the Z80. The breadboard on the left hand side is the clock circuit. All those black leads on the left of the Z80 are the data bus, which I've wired to the ground to set up a NOP, instruction 0. By constantly providing NOPs each time the processor requests an instruction, the system ought to start at address zero, go all the way to address 65535, and cycle around again. The LEDs are wired to the address bus, to give us an idea of the behaviour of the CPU as it cycles through the address range.
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Feb 2, 2013
Okay, so, small steps first. To begin with, I'll use a battery power source. This is the breadboard set up for everything else to go in. The 5V regulator seems to work fine. You'll also notice that the supply of chocolate biscuits is also still in good order (v. important). So, the plan today had been to set a Z80 up for a free run. Alas, it was not to be.
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Feb 1, 2013
I'll have 64Kb of address space to play with on the COLLIER-1, and this is how I plan on playing with it, from bottom to top.
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