An i8080 simulator

fabrizio · Post by **fabrizio** » Oct 26, 2007 13:11

This is my self made 8bit asm coding playground.

It contains the i8080 simulator, called "8080 Box" and a (cross) assembler, called "8080 Assembler", both in FreeBasic with source files.

Please let me know what you think.

Bye,

fabrizio

http://file-pasta.com/d/2219.zip

yetifoot · Post by **yetifoot** » Oct 26, 2007 21:20

looks like nice work, I did a z80 emulator in the past, very similar to the 8080

fabrizio · Post by **fabrizio** » Oct 27, 2007 7:46

You certainly worked a lot more than me: only 250 8080 instructions vs more than 700 Z80 instructions. My original goal was the Z80, but I grew tired earlier. If I was to start again now, I would opt for the 6502: ca 250 instructions but less repetitive because less registers and more addressing modes. You only discover these things after...

oyster · Post by **oyster** » Nov 10, 2008 11:40

hi, fabrizio
where does your program live now?

fabrizio · Post by **fabrizio** » Nov 10, 2008 13:16

Hi, thanks for your interest in my prog.
The prog waited patiently in my USB key until now, beacause development ceased after the post.

I uploaded it here (thanks Kristopher).

http://freefile.kristopherw.us/uploads/ ... 80_box.zip

Please let me know what you think.
Bye,

fabrizio

TheMG · Post by **TheMG** » Nov 10, 2008 16:04

I haven't tested this out or anything, but this sounds AWESOME! Mainly because I read a tutorial on compilers which coded with you as you go along. It was made a while ago, so the assembly output is for the 8080. I may be able to use your emulator for testing!

fabrizio · Post by **fabrizio** » Nov 10, 2008 16:10

Wow. Glad if 8080box may be of any help.
(Please forgive any bugs you might find.)

Cherry · Post by **Cherry** » Nov 10, 2008 19:19

Why is your program using TEXT FILES with the bytes written as ASCII NUMBERS? Why don't you use binary files?

fabrizio · Post by **fabrizio** » Nov 12, 2008 9:14

It was a deliberate choice. As much as possible had to be human readable. A simulator has this advantage over the real system, that you can actually stop a minute and look into it. So I let clarity prevail over adherence. The same applies to decimal numbers being used instead of the more obscure hex.

Furthermore, we are not suffering from the constraints in memory, storage or speed of the original systems, so we don't actually need to optimize: the simultaor will naturally run faster than the original.

Cherry · Post by **Cherry** » Nov 12, 2008 13:20

Yeah, but this way you can't run original binaries :)

fabrizio · Post by **fabrizio** » Nov 12, 2008 13:33

Yes, well. Programs in assembler are closer to the actual hardware and mine is invented from scratch. I doubt an existing i8080 binary could run as-is in 8080box.

In fact all I wanted was to try and program in assembler like one could do on the seventies and eighties computer. So I put together a CPU and a memory map, a screen and a simple assembler.

I hoped that maybe I could go on and translate a small OS like that of the Sinclair ZX80 (4K). That was where I realized I didn't like to program in assembler in the first place...

Anyway, if you feel like loading binaries, it shouldn't be difficult to add.

oyster · Post by **oyster** » Nov 15, 2008 6:36

thanks fabrizio :)
your code and doc are very clear for study