First released in 1993 and was Namco’s first arcade board that supported 3D textured polygon graphics. Namco collaborated with Evans & Sutherland for use with their TR3 graphics processor. This was responsible for texturing and applying 3D effects and functions like a graphics accelerator in a mid to late 90s PC (Like 3DFX Voodoo). The dual DSP processors, which are based on the Texas Instruments TMS320C25 generate the polygons which are then sent to the TR3 processor, where texture mapping effects and shading are applied
The board design bares some similarities to the earlier system 21 arcade board, which had dual Motorola 68020 processors and four Texas Instruments TMS320C25 DSP processors, which were responsible for generating the 3D polygons, on the System 22, this has been consolidated into a single 68020 processor running at 24Mhz, with the DSP being reduced to a dual TMS320C25 running at 49Mhz (MAME lists these processors running at 40Mhz)
Compared to the Sony PlayStation released a year later, It can produce graphics at a higher resolution, with additional effects added. This is notable with the ports of Ridge Racer and Time Crisis which run in both a higher resolution and a higher framerate. However, system 22 lacks support for hardware MJPEG decoding with limits its ability to do FMV. Many cutscene’s were done using the in game engine (Time Crisis and Prop Cycle have some minor 10 second cutscenes.)
Compared to the Sega Model 2 which the System 22 competed with, System 22 can render in a higher resolution (640×480, although this might be due to a design decision by Sega) and supports texture filtering. System 22 however supports gouraud shading which the Model 2 lacks. Model 2 however received upgrades, so depending on the board version, the capabilities may not be consistent.
References / Further Reading
The original arcade release which would later be ported to the Sony Playstation, running at 60fps at 480p. With Ridge Racer is a racing game with drift mechanics and an amazing electronic/techno soundtrack.
Ridge Racer 2
An update of sorts to the original ridge racer release, which added multiplayer mode with networked cabinets and a rear-view mirror. A revised soundtrack with new songs plus remixed versions of the existing ones bring the count to 12 in total.
Ace Driver: Victory lap
The last instalment of Ridge Racer on System 22, and the last Ridge Racer game for arcades until 2000 (Ridge Racer V). This one features 4 (well 3) different tracks, an updated soundtrack and some bonus hidden modes along with a third person car view.
System Super 22
System 22 received a minor upgrade in 1995, known as super system 22. The main difference stems from n updated TR3 processor which is supposed to be capable of additional effects. The main difference comes from its sound implementation, with the original 22 having two Namco C74 processors, which were basically a Mitsubishi M37702 clocked at 16.3Mhz. Super 22 replaced this with a single M37710 at the same clock speed, likely to reduce the cost. The size of the system itself was reduced, but the CPU board was split into two, resulting in the CPU board and a separate DSP board, in addition to the dedicated video board which was present in the original system 22.
Air Combat 22
Downhill skiing game
Alpine Racer 2
Like wave race on the Nintendo 64
A rather unusual game, the objective here is to collect/pop all the balloons before time runs out with some balloons extending the time. The game’s story is even more bizarre, involving a nuclear explosion causing some parts of a village to ascend into the sky. A better explanation here – In Japanese so you need a translator
Kind of like an early FPS but with tanks, there are two teams of tanks with the objective to eliminate all tanks on the opposing team.
Based on the original PlayStation hardware, which has been customized to load data rom surface mount ROM instead of CD-ROM.
There are multiple contradicting specifications for this hardware, mainly in relation on the GPU and VRAM configuration, with some sources listing it as having 2MB VRAM, which is twice of the amount shipped with the PS1. Its worth noting that in the arcade release of Tekken, the character select screen have a few frames of animation after a character is selected, with the PS1 using fixed/static character portraits. Regarding gameplay itself, there does not seem to be much difference in the stages or character models themselves.
Early PlayStation consoles used an early revision of the GPU which used VRAM for its memory, this is present in System 11. Later revisions of the PlayStation used a revision of the GPU, which used SGRAM instead of VRAM, likely due to the reduction in cost for SGRAM chips, due to the use of the in PC 3D accelerators. The CPU is clocked at the same speed as the Playstation.
The main difference with this board is the sound hardware, whilst it contains the same SPU audio processor, System 11 also used a custom Namco sound chipset, similar to the one found in System 22. This was because many Namco PS1 games used red book audio for their background music, where the PS1 acts as a CD player, with little processing overhead, as System 11 used surface mount ROM chips which were limited in capacity compared to CD audio. Also, since arcade board’s are designed to be left on for significant amount of time throughout the day, wear and tear of the CD laser would have been an issue.
[Hardware Mod] 8MB in (PU-18) Retail PSX – Page 2 – PlayStation Development Network (psxdev.net)
SCPH-7502 = Better graphics ? (“PS1.2”) – PlayStation Development Network (psxdev.net)
Sony Playstation GPU 600nm Specs | TechPowerUp GPU Database
PlayStation Architecture | A Practical Analysis (copetti.org)