Tuesday 30 December 2014

Apple I replica computer build

My wife kindly purchased me a replica Apple I kit as a Christmas present, (the kind of present where I buy it and she pays me and wraps it up. lol!) The Apple I was the first computer designed and engineered by Steve Wozniak &  Steve Jobs. 

The kit is a replica made by Briel Computers. Inside the package was the following items: Blank PCB, Components & a CD containing build instructions, software and some original Apple I info.

Contents of the Apple I replica kit.
After a quick read of the build guide, I installed the components in what I deemed the best order.

Passive components, Power switch, Crystal USB->Serial headers installed.
All IC sockets, PS2 and Video Phono connectors installed. 
IC's and USB to Serial adapter installed.
So that was all the components installed, I double checked that everything was installed the correct way around. The first check was the 3.3V from the USB adapter, this is used so you can a) power the computer and b) connect a terminal program from a computer to send files and type code. There is an onboard PS2 connector to plug a keyboard in directly or even an ASCII keyboard connector which the Apple II used (I think).

So the 3.3V was good, next up was the 5V line which powered all the IC's. Again this was good so I hooked up the monitor.

1st power up, the screen is full of garbage.. this is what's expected. Yes!

After a quick press of the 'clear' button followed by the 'reset' button I'm staring at and "@" sign, this is the Apple I prompt, you are now in Woz Monitor mode, here you can set and view memory locations and program directly to the 6502 processor. The ROM that comes with this Replica has Apple Basic installed, back in the day you would have to build a Tape interface and load it into RAM from Cassette. To get into basic, you type E000R and hit return. There's also an assembler called Krusader built into the ROM, this is a assembly language dev tool for the Replica I which can be run from location F000R. This is what I'm going to be looking into once I've finished playing with some of the existing software releases for the Apple I.

A very basic Basic program!

I'll post some more updates, if/when I make any progress with anything that may seem remotely interesting.

Regards, Smart.