Today we discuss Sega Genesis (or Mega Drive). The 16-bit game consoles held a special place in game history. After the 8-bit machines became extremely popular in the mid-1980s, companies had more resources to pour into R&D of the next generation, leading to more sophisticated designs. And the users truly desired “arcade-level performance”, hence the “Blast Processing” marketing by Sega. These machines were well-received and significantly pushed the industry forward. Although companies like NEC and SNK entered the home console market during this period, the main rivalry was between two companies, Nintendo and Sega. SNESTang has been available for some time now. It is about time I bring the other major 16-bit machine, Sega Genesis or Mega Drive, to the Tang boards. MDTang 0.1 is a port of Genesis-MiSTer to Tang Mega 138K/138K Pro. In the future, it will also support TangConsole 60K when it is released.

GBATang has been improving pretty quickly since its release and just reached version 0.4. More games are running. Graphics rendering has improved a lot. And sound bugs were fixed. Continuing part one, let us discuss the components that were not covered in the first post.

Here are a few tips and tricks for using the Gowin EDA IDE and Tang FPGA boards, such as Tang Nano 20K, Tang Primer 25K and Tang Mega 138K. These are small things that I wish I knew when picking up the Tang boards. Gowin is a relatively small FPGA vendor and documentation is not that complete. So I hope this is helpful for the community. If you are coming from Xilinx or Intel FPGAs, you may also find these useful for quickly getting started.

Version 0.1 of GBATang is just released. It is the first FPGA core for a 32-bit console available for Tang FPGA boards (Tang Mega 138K and the upcoming 60K). The journey is an interesting one for me. This first blog post discusses the experience of porting and building this core, its overall technical design and in more details, the CPU part.

In part 1, we discussed why we need a softcore for SNESTang, and how it can use SDRAM in a way that does not disrupt the gaming core. Now we need to provide a firmware program to to make the softcore useful, like displaying a menu. In this part, let’s explore the building and loading of the RISC-V firmware to get the soft core to do useful work.

In the recently released SNESTang 0.3, a softcore-based I/O system is added to enhance the menu system and file system support. Let us explore how this works. Part one of the article discusses why the soft core is necessary, choice of CPU to use and how it works with the SDRAM.

This documents the design of SNESTang 0.3 for my own reference and others who want to read the code. It also aims to be helpful to people porting other cores to Tang FPGAs.