Apple 1, Replica 1 TE Briel Computers Part 3: Programming

There are three ways of programming the Apple 1:

  1. The WOZ monitor ( direct access to memory to program code that the 6502 will interpret). Just hit the reset button and you are in the WOZ monitor. Later on more information about this topic
  2. BASIC, there is a build in BASIC ROM with the original Apple 1 BASIC ROM which was used among beginners to experience programming the Apple 1
  3. The Krusader  assembler written by Ken Wessen, for more information look at this website: Krusader by Ken Wessen 

First of all I use a Hyper Terminal connection with my Apple 1 to communicate and send data to the Apple 1, this save a  lot of typing 🙂

Quick steps to setting up Hyper Terminal connection:

  • Start a new session of Hyper Terminal and select a name for your session.
  • Click on OK and select which COM port you are connected to and select OK.
  • Set up your COM port as following: 2400, N,8,1
  • Select OK and continue on to starting Hyper Terminal and disconnect this session.
  • Click on “File” in the menu bar and select “Properties” from the drop-down menu list
  • Click the “Settings” tab at the top, and then select the “ASCII setup” button.
  • Use these settings:

  • Close the properties window and return to Hyper Terminal.
  • Now click on the “Connect” button.
  • Make sure that Caps Lock is ON.

Now it is possible to use your computer for input to the Apple 1. Use the Send text file to send assembly or Basic programms to the Replica 1 or the Capture Text option to capture the Replica 1 output and save it as a text file.

First I’am goning to program the famous “Hello world” in Apple BASIC. To enter the Apple BASIC, reset the Apple 1 and than type “E00R” followed by an enter. Now the Apple 1 is ready for programming BASIC, type in the following BASIC code:


20 GOTO 10


Output is:

To use the WOZ monitor, just hit the reset button and wait for the / to appear on the screen. Now you are able to read and write data directly to the memory ($0000.7FFF are available memory) of the Apple. After writing the program to the memory, type RUN to start the program. For example if you type the following test program in the memory 0:

0: A9 00 AA 20 EF FF E8 8A 4C 02 00

then type RUN to start the program.

And finally the Krusader assembler.


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