A new service release from FPGA core developer Jotego brings significant stability improvements for Analogue Pocket users and marks a major milestone with the public release of a highly anticipated arcade core. The update focuses on core stability, custom CPU development for accuracy, and laying the groundwork for future high-profile projects.
Analogue Pocket Stability and the Road to CPS3
The most critical fix in this release addresses stability issues for the Analogue Pocket. The frame buffer for 96MHz cores was stabilized, ensuring the Run ‘n Gun core now works reliably for all users; previously, many experienced a blank screen. Jotego noted that this stabilization feature was also a necessary prerequisite for the development of the JTCPS3 core. The developer emphasized that the CPS3 core is one of the most desired, particularly for playing classic titles like Street Fighter 3: Third Strike.
The SEGA System 18 Core Enters the Public Domain
After a long development period, the core for the multi-game arcade platform SEGA System 18 has been officially made public by Jotego. The core is considered “solid,” though the developer noted that the sound balance is an area that can still be improved.
Games available on the System 18 core include a variety of classic titles:
- Shadow Dancer: A celebrated sequel to Shinobi.
- Moon Walker: The isometric arcade version featuring Michael Jackson’s songs.
- Alien Storm: A fan-favorite brawler.
- Other titles such as Bloxeed (arcade Tetris), Clutch Hitter, D.D. Crew, Desert Breaker, Hammer Time, Laser Ghost (a light gun game, which supports the Sinden light gun on MiSTer), and Where’s Wally/Waldo.
Custom CPU and Improved Accuracy
The update includes significant work by Jotego on CPU modules to ensure cycle accuracy:
- Cycle-Accurate 65C02: Development for SETA’s Caliber 50 core led Jotego to discover that its 65C02 processor is not fully compatible with the standard 6502. The developer had to create a new, cycle-accurate 65C02 JT module to accurately emulate the hardware, as existing online modules were insufficient.
- Wider Adoption: Since the new 65C02 is backwards compatible, various existing JT cores that previously used the 6502 have been updated to utilize the new module, including Data East games such as Renegade, Dragon Ninja, and Robocop. The Caliber 50 core itself is still under development, with the 65C02 work being a foundation for that project.
- 68xx CPU Cycle Errata Corrected: A review of design files for other 68xx CPUs revealed and corrected a couple of minor errata related to CPU cycles. Although Jotego suggested this may not be noticeably different during playing, the fix ensures greater accuracy for games like Double Dragon.
Future Development Pipeline
Several new core projects are moving forward in Jotego’s pipeline, with preliminary work now complete:
- The schematics for Konami’s Premier Soccer have been finished, and core conversion is the next step.
- Kaneko’s Gals Panic is next up for schematic conversion.
You can support Jotego and teams FPGA core development efforts via Patreon.