Here’s a summary of a quick and fun weekend project. For tl:dr people : Download the IPS file and run it together with your School Fighter ROM dump. @inobscurity wanted to try the unlicensed HK game School Fighter for the GBC, but the ROM dump would hang before the first level. I had just…
ROM Dumping in progress…
Well, as seen in a previous post I damaged the main board pretty seriously while removing the ROM daughterboard, but still had hopes it could be salvaged. In the process of making everything work, sadly, it became obvious that I would be unable to solder connectors to some of the lower…
First successful code build.
Here is the small, but significant, first step into programming the VT168. Using a standard build of the cc65 C compiler and a draft configuration file, I successfully mapped the memory and structure of the VT168 hardware. With that and the available register documentation, I had a sample running in…
NJ Pocket memory reverse engineering.
I finally got around to figure out the pinout of the little Flash ROM board in the NJ Pocket. For that I had to remove it to check the bottom pins… and well, let’s say things didn’t went very well: Despite my best efforts to safely remove it, the board…
Software Sprites With a Tile Based Display
Earlier today, I was talking about the Sega Mega Drive and how it sometimes used software sprites (but mostly its predecessor, the Sega Master System). This made me think of the technique for a while and how I haven’t seen it detailed in any length for a while. It was not that…
VT1682 Schematic Symbols
I took a quick break to map the pinout of the VT1682 CPU unto a library for my favorite schematic editor. I use an old version of bSch i translated into English a couple of years ago. It runs fine, even on Windows 7, but the tools that convert the…
NJ Pocket initial signal analysis
To add to my previous post, I ran my oscilloscope over the pins on the small board. It exposes 44 pins, and one would expect to see 16 data pins, and the full 21 addressing space. So a quick look revealed 23 pins with a waveform like this: That seem…
Exploring the NJ Pocket
To start this blog, I want to focus on a piece of hardware that has caught a bit of interest recently. It is the NJ-250A “NJ Pocket”, a very cheap (under $20) console that can be obtained from several internet retailers:The machine itself is manufactured by Shenzen Nanjing technologies. While…