Techy Things @ZephyrZ80@mastodon.technology

Made a disassembler module for my Z80 computer's firmware, also included it as a subroutine call in the firmware's debugger.

I made a thing.

Working on getting a microSD card working with my Z80 computer. If I get it working right, it's gonna be bonkers to have 4GB of storage space on a machine with only 32KB of RAM.

I do want to add some more functionality to it. First one is to include a 'preview' of the selected area, so the user gets some feel for what the region would look like as the computer does a proper render pass on it.

So a few days ago I managed to fix a bug with my Z80 mandelbrot program, so now it's accurate in its output. Before and after images

I don't mean to be negative, but I have too many electrons.

There are 10 kinds of people:
Those who know hexadecimal and F the rest.

You could use the user port to make a communication bus, so the primary C64 can task the secondary C64s with points to test.

Imagine using a cluster of Commodore 64 computers to render the mandelbrot set.

First C64 assembly program

Me: Perhaps I should do something useful with my computer project.
Also me: *Writes software for an obscure and fictional computer architecture, because reasons*

Added color to my 32-bit precision mandelbrot program, running on a Z80 SBC prototype, with user I/O via serial.

Especially when you're doing it in Z80 assembly.

So, turns out programming a chess game with AI is kinda difficult.

I think now I want to write either a program that calculates optimal ratios for Factorio recipes, or a Tetris clone. Maybe both, just not sure which to do first.

So, for kicks I decided to see if my BBZ80 homebrew computer is capable of serial speeds greater than 4800, and it turns out it can go up to 38400 baud, despite it being at least 1.7% off of nominal. So I got an 8x speed boost from it with no hardware changes.

A useful example:
On startup, flash is mapped to the first block. You can then remap the first block of RAM to be in the third block of the address space, copy flash to it, and swap that block of RAM to the first block of address space, to seamlessly switch to running your code from RAM without any tricky jumps in the software.

The chip-select logic is pretty interesting. It allows you to set what /CS, /WE, and /OE lines are active for each 256KB block of address space, and you can also invert the A18 and A19 lines to map blocks of memory to different address spaces.

I'm doing a bit of a hack with the RAM. I'm treating the 16-bit RAM as two separate 8-bit RAMs with the CPU's built-in chip-select logic.

Started designing a single-board computer using the Rabbit 2000 CPU. Planned specs so far:
29.5MHz max clock speed
512KB of flash memory
2MB of RAM
MicroSD card storage
Plenty of GPIO pins
Header for an FTDI adapter

There will of course be expansion headers, so you can add video/keyboard interface capability, or other peripherals based on requirements.