More work on my port of SimCity to the Gameboy Advance. With the help of the gba development discord, we were able to extract the 8x8 MCGA tileset from the DOS version of SimCity.

Working on porting Micropolis (SimCity) to the Gameboy Advance. Pictured on a DSi, it is running in GBA mode. Source: github.com/TaraHoleInIt... All it does now is run without sprites and you can scroll around.

I was curious if I could get Micropolis running on the GBA, and the answer is maybe? Problem is that the GBA tile engine can only address 1024 8x8 tiles, while Micropolis uses 1024 16x16 tiles. It's taken a lot of fudging the tile data, but I believe it might be reasonably possible.

I wonder if I should move my Micropolis (SimCity) port from ESP-IDF to Arduino. Not that I don't like ESP-IDF, but this might open it up to being usable on more platforms. Like, I need to use my TFT_eSPI shim for LCD initialization currently, but I know most won't bother.

Devs: How would you plan out a sprite renderer that can properly handle sprites that are partially off-screen? I'm planning on doing a naive cull to start, but I want to know how to plan a better sprite renderer. Do you start by sketching things out?

Hitting a bit of a snag porting SimCity to the ESP32: the graphics are indexed but do not use a global palette. So sprites each have their own palette, but that palette often differs (by index only) each frame? I need a way to create a global palette from all of the graphics somehow.

More SimCity on the ESP32. I rewrote the tile engine to render into an indexed frame buffer which gets converted and pumped out over SPI in 16px tall chunks. Currently at ~39-41ms for a full frame including rendering and sim ticks. I still need to do scrolling and sprite rendering.

More Micropolis on the ESP32. I still need to write a sprite renderer, though.

Debating/testing the waters on porting Micropolis (SimCity) to the ESP32... At first I just wanted to see how fast my tile rendering was, but now I'm wondering if I should keep going. The fastest I've been able to get is ~44ms to fill a 320x480 screen at 240MHz with an 80MHz SPI clock.

Debating having this made for messing around with Z80 stuff. What you would do is stick a breadboard in the middle and wire up your computer as modules. A larger breadboard would serve as a kind of backplane once you connect the rails together. I'm a bit worried about the pin alignment though.

Z80 executing NOPs. Big thanks to @ruenahcmohr.bsky.social for helping me get this started. I think I’m going to have to find a way to make it cleaner though, it’s already messy :)

Tested and working: DS1232 MicroMonitor chip

NEC D71055C (i8255) blinky with ch32v003.

Scavenged parts round 2: NEC D71051C - Serial control unit NEC D71055C - Parallel interface unit NEC D720010 - Multi-protocol serial controller NEC D71059C - Interrupt control unit NEC D71054C - Programmable timer/counter 1x 74HC04 2x 74HC373

Idea: build a 6502/z80/v20 computer using at least 80% scavenged components. Not sure about passives, I'd probably use new, but I have a TON of boards with neat stuff on them just waiting for a harvest.

Wait… Are THT capacitors just SMT in disguise?

Scope creep: Step 1: “I should build something to monitor an 8bit cpu bus” Step 2: “Maybe it should be able to write to the bus?” There is no step 3, I kinda get lost in the clouds and not build anything.

As school winds down and hopefully I graduate, I need to find a new project to work on. Maybe 6502 based? Something weirder maybe? Maybe something practical or useful? I need more portfolio pieces anyway now :)

I’m not sure how to solve this problem. The threads on the standoffs are too short, but they don’t seem to make longer ones. Any ideas how I can mount this PCB? I do have those knurled screw inserts, but the plastic isn’t solid so I’m a bit scared of ruining my only 3d print.

Writing thousands of lines of code: OK Designing and building hardware: OK Crimping a ribbon cable strand onto a dupont connector: FUCKING IMPOSSIBLE I swear I've tried hundreds of times but it just won't work. Is there a trick to this that the dozen of youtube videos I saw missed? I'm going crazy

I'm trying to desolder a through hole pin header, and while the pins came off easily I cannot for the life of me get leftover solder out of the hole with wick. I mixed in some leaded solder to take the pins off, but I wonder if there is still some left behind? Any ideas?

Trying to take pictures of the sky.

Great. Totally fine that fetish posts appear not only in the discover feed, but on the main feed as well “from discover” in my main feed as well. I won’t be reading this app in public anymore :(

Just curious how feasible manual pasting and hot air soldering of 0402 parts is. They look terrifyingly small.

Yay: Part of my PCB works! Noooooo: USB Does not!

PCBs came and this one seems to program. I’m a bit afraid of checking further in case I made a boat anchor, in which case I would be emotionally devastated for several hours to a day or so. If I never actually test it then it’s possible everything works.

I have no idea if I’m doing this correctly or if I’m about to make expensive e-waste. Anybody used these kind of ribbon cables or displays?

Pointless, but it was fun to try.

For a while now I've been working on a kind of "shim" to allow the TFT_eSPI Arduino library to initialize displays without using the Arduino framework. github.com/TaraHoleInIt... All this does is provide a small layer between TFT_eSPI's display drivers and the interface you write for your platform

God that ratsnest looks indimidating... I really hope I'm not going to create e-waste right out of the gate.

Finally got around to playing with this scope to help debug issues with SPI speed beyond 18MHz. Well, it looks like the 10x probes that came with this interfere with anything beyond ~8MHz. Still, that can't look good, right?

Just how bad for signal integrity are flying wires? My current project uses a ch32v203 development board which is not breadboard friendly, and as such there are wires EVERYWHERE. I really should get a PCB made, but I still feel like I'm not at that stage yet. I don't wanna make e-waste.

I just spent hours trying to debug why tinyusb wasn't enumerating only to find out it's because of the USB hub I'm using? What the heck? It worked on Windows a windows PC though, just Mac + hub brings out the problem.

Bitbanged WS2812B LEDs on the Adafruit QT Py CH32v203. I wasn't expecting this pattern at all, I just started out rotating bits to the left and was pleasantly surprised. This is my first time driving addressable LEDs with my own code.

I've been playing with the CRC hardware on the ch32v003 for a while, and so far 8-bit CRCs work fine if not reflected and the starting value is 0x00. No luck so far on CRC16. If the hardware requires the input be byteswapped then that kinda kills the idea of using DMA to calculate a CRC :/

Prolly fine… CMD8 Succeeding so far, but lots more to go.

I opened up my PS2 for a deep clean to discover whatever this damage is. Any thoughts on a repair strategy? I couldn't remove the shielding or take it apart further without risking damage. My best guess is epoxying the plastic and leaving it in a vice for a while. All I have is a metal vice though.

Odd question about software licenses: I wrote a working serprog implementation for Flashrom using the protocol specification and referencing the source to see what it expected. Flashrom is GPL licensed, but I prefer to keep everything MIT for simplicity.

All working good so far using the rp2040 to push flash into an lcd. Next, I need to implement DMA to keep the SPI peripheral going.

I'm currently revisiting something I did years ago, and I wanted to give more thought to this potential problem. Normally, when I've done this before, I've tristated MOSI on the MCU which seems to work fine. Part of me worries that it might not be enough, should more hardware be added?

I finally got around to making the debug probe for the rp2040. With it, I was able to write a serial port interface to flashrom and write to SPI flash. I suppose soon I have to start thinking about making a PCB, but it feels more daunting with these faster, more powerful chips.

Is Microchip's AVR software painful/expensive to use? I need an MCU with built-in USB, and I got a couple avr16du's before doing research lol.

Well, that's a new one. Bringing my hand closer to wires on a breadboard is enough to show up as weird noise on my logic analyzer. I don't remember seeing this before, and maybe this also explains why my ch32v003 sometimes fails to program.

Working on running TFT_eSPI on the ch32v003 with the ch32v003fun framework. I’m writing a basic API to use the init functions from TFT_eSPI with plain C. This ILI9341 and an ST7796S are working so far 😀

Finally got this sort of working after fighting with some incredibly dumb bugs. This is a ch32v003 microcontroller dumping the contents of SPI flash directly into a 480x320 display. Still have to fix a bit more bugs with the colours being inverted (normal when doing regular SPI transfers).

What do you do if while in the middle of a project you discover someone else already did it? I’ve had this happen a few times, and it always kinda kills the enthusiasm.

Got these from my dad, but I need to make so much more space before I can set them up. Same deal with that really heavy analog scope he gave me last year. I hate making space because it always means throwing out something I’ll need later and not know it.

Welp. I’ve finally reached the point where I need to take out my phone camera to read the text on ICs. Or, I could start organizing and labelling all the random ICs stuck into foam rather than moaning about it.

Switched clock to a 555 timer and all is well with the 65c02 :D Now I can hook up the ROM and RAM as well as think of how I want the address space to look or just what the heck I want to get out of this.

I should try to memorize how to set up a 555 timer in various configurations. Mostly because I'm being lazy and it's hard to be assed to look it up each time.