Tuesday, 7 August 2012

37. Raspberry Pi Case.

Just got this case for my Raspberry Pi.  I got it from http://www.modmypi.com.  Its very good.  Fit is perfect, it doesn't rattle around in the case and the quality is very good too.  You can choose any colours you like and even mix and match top and bottom case colours.  The case clips together very solidly and comes with some stick on clear rubber feet. Well worth the money.

Friday, 3 August 2012

36. Apple 1 - Hello World!

It's been a while. I've been getting distracted by all things geeky. I thought I'd share this though.

I became curious by the Apple-1, the original must have Apple product, the Ford Model T of computers if you like.  All you got was a circuit board, but no keyboard or monitor (a bit like the raspberry Pi of its day).  I decided to look for an emulator for it, and at this stage knew nothing of the Apple-1's underpinnings.  It wasn't a Z80 but my old friend the 6502.  I've not touched the 6502 since secondary school when I used to play with the Commodore PET/CBM in the early 80's.

I got the Pom-1 emulator in Java flavor and downloaded the Apple-1 manual.

I soon realised that to program the Apple-1 you just entered 6502 machine codes and ran the machine code programs.  No BASIC interpreter (although there is a 6502 program for the Apple-1 that you can load in to get BASIC).  So I set about relearning 6502 machine language and so far my efforts have resulted in my first "Hello World!" program.

Here's a screenshot of the code and it running:

\ is the only screen indication that the Apple-1 is alive.  0.22 displays the first 23 bytes and R runs from address 0.

Why is this relevant?  Well this is something like what I want to build with the Z80