Sharp 80: Z-80 Assembler
Sharp 80 comes with an assembler that uses a standard syntax for creating your own CMD files. You can use any opcodes in the entire Z-80 Instruction Set.
Here's an example of a simple assembly program:
Important: the columns in the program must be separated with tabs, not spaces.
|; fill screen with 'X's|
|ORG||6000H||; start here to avoid ROM and system areas|
|ENTRY||DI||; don't let interrupts reset the system|
|LD||HL, 3C00H||; beginning of video RAM|
|LD||BC, 0400H||; 1K of characters on the screen|
|LD||(HL), A||; put the X on the screen|
|INC||HL||; move to the next character|
|JR||NZ, LOOP||; loop back if we haven't counted down to zero|
You can type this program into a text editor and save it with a filename that has an .asm extension, like 'myprog.asm'. You can then run it in Sharp 80 by:
- Start Sharp 80.
- Hit Alt+Y to invoke the assembler, and open the asm file.
- The program will automatically assemble, and you will go to the CMD file screen.
- Hit L to load the assembly file into memory.
- If you don't have the CPU internals view showing on the right, hit F5 to show it.
- You should then see your program in the disassembly section, starting at memory location 6000H.
- Hit R to run, and the screen should fill with 'X's.
To see a more complex assembly program, open the zexall.asm file that's included at C:\Users\<your windows username>\AppData\Roaming\Sharp80\ASM Files\zexall.asm. This program will thoroughly test the Z-80 processor.