Replica 1 plus Users Manual Chapter 7: Using the Krusader Assembler Krusader is a powerful assembler written by Ken Wessen for the replica 1. This assembler makes programming the 6502 processor in the replica 1 a breeze. No hand converting mnemonic instructions to hex then manually entering them in the Woz monitor. Now you can program using mnemonic instructions, assemble and run your program right from the assembler. To enter the assembler, type in: F000R [return] The program will begin and the authors name and current revision will appear. Next line will display a ‘?’ with the cursor next to it. Type ‘N’ to enter a new program. The assembler will now display ‘000’ for the first line.
Let’s enter the program listed in the Krusader as an example program. 000 is now displayed. Press space bar to skip the first field used for naming code blocks. The assembler tabs over to the next field. Type LDA #’A’ [return] ; 001 is now displayed. Then type LOOP then press space bar to tab to the next field. Type JSR $FFEF [return]. Type in the rest as shown: 002 CLC 003 ADC #$1 004 CMP #’Z’+1 005 BNE LOOP 006 RTS Once you have entered in the source code, type L to list out the code, and then A to assemble it. To run your code type R $300 . The program will run and output the string:
ABCDEFGHIJKLMNOPQRSTUVWXYZ Once the program finishes with the RTS command it will return to the Krusader assembler shell. To learn more on how to program using Krusader, refer to the Krusader owner’s manual or visit the Krusader web site at: http://school.anhb.uwa.edu.au/personalpages/kwessen/apple1/Krusader.htm © Briel Computers 2014 page 26