First sign of life (Patreon)

Hi everyone,

I started writing a software emulator for the next console I'm working on. As always, I learn about a new system with a software emulator before writing the FPGA core, because of much shorter development loops and easier prototype building. Also these software emulator are often useful for bugfixes later on, especially for things that cannot be observed easily in a FPGA core.

What you see in the image is a program I have written in assembler for this system. It's nothing exciting yet, but what does it mean?

Milestone number 1 is reached!

Nearly all systems require some kind of startup routine, which usually works through a BIOS or bootrom until the application software can take over.

Depending on the system, this can be short(Lynx) or long(PSX), but each emulator or core must get through this to be able to run any real program.

So what this simple screenshot tells you: my emulator fully passes this bootstage now and we can conclude several things from that:

- the CPU must be working to a significant degree

- the memory access to ROM and RAM must be working

- setting up basic IO registers must work

What more can we see from the screenshot? Well, the graphical output also works already, otherwise we could not see anything.

With this in place, I'm now able to try and run all kind of homebrew or original software. While most fully-fledged programs won't do anything yet, being able to run testprograms for all the subsystems already opens up a large field of things to work on and validate. 

This is what I am currently doing: make sure the testprograms I have, either existing ones or written by me, shall work the same as on the real system.

From now on, components can be added one by one, enabling more and more functions of the systems, allowing more and more software to run.

Hopefully with the next update I can already present you something more exciting on the screen. But until then, please give me some more weeks.

Have fun!