We come to the last game update for the JTCPS3 core: the Third Strike. For those who know the game, this needs no introduction, for the rest: boot it up and just watch the art. Watch the use of color for the backgrounds, for the clothes... All that was hand drawn, no 3D models, no shading calculations, no prompts.

Third Strike is the biggest game supported by a JT core so far. The stream file from your SD card to the FPGA is 82,432 KiB. Before including CPS3, this honor fell onto Vampire Savior, with 45,320 KiB. Third Strike is almost twice as large. The smallest game we have in the catalogue is Konami's Ping-Pong 48 KiB (2,000 times smaller). A better known title is Circus Charlie (144 KiB) or Ghosts'n Goblins (352 KiB).

Despite this large disparity in size, Third Strike is an arcade to its bones. It operates on tile maps for backgrounds, like those games. It has hardware sprites, like those games and it also has a DMA mechanism related to sprites like Ghosts'n Goblins. The digitised sound capability (PCM) was there in Circus Charlie. Even the number of image lines is the same Konami's Ping Pong.

The biggest difference from a hardware point of view is ROM size. That enormous ROM lets the game play all music based on digitised sounds, without pulse or FM sound synthesizers. The gigantic ROM is what makes possible the breath-taking smoothness of its animations. The enormous ROM is what made this game impossible to convert 1:1 to a 1999 home console.

One caveat: the video timing is the CPS1/2 not the CPS3. So it runs slightly faster than it should (59.64Hz). I made this change a while back for better compatibility with consumer CRT TV’s. I have to get to a better arrangement that preserves the original speed while working well on old TV’s.

New JT8051 MCU

Many systems used an intel 8751 microcontroller unit (MCU) to do small side tasks. The other big change for today's release is the replacement of the Oregano 8751 MCU core for my own cycle-accurate JT8051. This was a request to make Space Harrier possible because the Oregano MCU is not cycle accurate.

This was something that bothered me but because this MCU usually takes a very small role, like providing key values that serve as a copy protection mechanism, it wasn't critical. But, as it happens every now and then, some systems require exact accuracy to operate and Space Harrier is one of them.

For now, no new game core but a lot of old ones are updated to use the new MCU. This is not the full list, but you get an idea:

That's all for this week. Enjoy!