PlayStation | Code Like It's 198x

Sony’s first games console began as an accessory for somebody else’s. In 1988 Sony agreed to build a CD-ROM drive for Nintendo’s Super Famicom, and planned a machine of its own that would play both Super Famicom cartridges and Sony’s new “Super Disc” format. Sony called that machine the PlayStation. Nintendo walked away from the deal in front of the world’s press in 1991, and Sony built a new PlayStation on its own. When it reached Japanese shops on 3 December 1994, Edge called it “the hardware launch of the decade”.

What surprises most, reading Sony’s own hardware manual, is how much of a standard workstation processor the company left out. There is no memory manager and no floating-point unit. In their place is a coprocessor that does 3D maths in fixed point, and a kilobyte of fast memory the programmer controls by hand.

Fast facts

Manufacturer: Sony Computer Entertainment.
Launch: Japan 3 December 1994; North America 9 September 1995; Europe 29 September 1995.
Price: ¥39,800 in Japan; $299 in the US; £299 in the UK.
CPU: a customised R3000A, 32-bit RISC, at 33.8688 MHz, little-endian.
Caches: 4 KB instruction; the 1 KB data cache is a programmer-controlled “Scratch Pad”.
Coprocessor: GTE, the geometry transformation engine, working in fixed point.
GPU: draws triangles and four-sided polygons, with Gouraud shading and texture mapping through a 2 KB texture cache.
Colour: 15-bit direct (32,768 colours) or 24-bit direct.
RAM: 2 MB main, 1 MB video, plus a 512 KB sound buffer the CPU cannot address.
Sound: SPU, 24 ADPCM voices at 44.1 kHz.
Media: CD-ROM.
Sales: more than 102.4 million, by Sony’s count.

From Super Disc to PlayStation

Two accounts from the 1990s tell the story in close agreement: David Sheff’s history of Nintendo, Game Over, and a long Edge feature for the PlayStation’s Japanese launch in February 1995, which draws partly on Sheff.

Both date the agreement to 1988. The technology was CD-ROM/XA, which Sony had developed with Philips, and the machine Sony planned would carry a Super Famicom cartridge slot as well as a CD drive for Super Discs. The contract gave Sony control of CD software. When Sony announced the machine, Sheff writes, it emphasised that it was the “sole worldwide licenser of the Super Disc format”. Nintendo had built its business on controlling every game that ran on its hardware, and by 1991 it saw the deal as a disaster. Edge adds an older grievance: Ken Kutaragi had designed the Super Famicom’s sound chip, and Sony kept the rights to programming it and “charged Nintendo excessive fees” for the information its developers needed.

A month before the June 1991 Consumer Electronics Show in Chicago, Hiroshi Yamauchi sent Minoru Arakawa and Howard Lincoln to Philips in Eindhoven to arrange a rival CD-ROM deal. Sony announced its PlayStation on the first day of the show. At 9 o’clock the next morning, at Nintendo’s own press conference, Lincoln announced that Nintendo would work with Philips. Sony had learned of the plan 48 hours earlier, and both accounts say its chief executive, Norio Ohga, telephoned Yamauchi to try to stop it. Lincoln told Sheff: “There were tremendous efforts on a worldwide basis to keep that press conference from happening.” Sheff quotes Olaf Olafsson, who ran Sony’s electronic publishing business, telling a confidant: “They stabbed us in the back.”

The companies went on negotiating. Sheff dates a new agreement to October 1992, under which Nintendo would license the games for both companies’ CD machines. Edge describes a deal at the end of 1992 that let Sony’s machine run Super NES CDs while Nintendo kept the rights to its games. The hybrid still never went on sale. Edge reported that it reached the prototype stage and that “around 200 original PlayStation units” were sitting in Sony offices around the world. Looking back in the late 1990s, Lincoln told Andy Eddy that the Philips move “seemed like the correct business decision”, but “we certainly knew we had deeply offended Sony.”

Sony started again. The new machine, first called PS-X, surfaced in late 1993, a dedicated games console with no cartridge slot. Sony spent the following year signing up developers. By the Japanese launch, Edge counted more than 250 companies signed up and some 700 development stations shipped. Namco had agreed in 1993 to write PlayStation games and to build arcade boards on the same hardware, and its Ridge Racer was the launch game shops used to demonstrate the machine. Sony had bought Psygnosis the same year, and in Britain its WipEout was the best-selling game when the PlayStation arrived in September 1995.

The launch

The Japanese launch shipped 100,000 machines to shops. Edge queued at Bic Camera in Ikebukuro on the morning of 3 December and paid ¥37,000, ¥2,800 below the ¥39,800 list price. The box held the console and one joypad, with no game. The queues were smaller than those for Sega’s Saturn eleven days earlier, which Edge put down to one missing game: the Saturn had Virtua Fighter. The magazine’s own verdict on the hardware was unreserved: “Sony hasn’t overlooked a single thing”.

What Sony left out

Sony’s developer manual is at its most revealing when it describes what is missing.

There is no memory management unit. A standard R3000A has a translation lookaside buffer (TLB), which maps the addresses a program uses onto physical memory. Sony’s does not:

a TLB, which is the virtual memory management device for the R3000 CPU, is not mounted. Therefore, the relationship between the physical address and the logic address of the memory space is always fixed.

A game sees 2 MB of main memory at fixed addresses, with nothing between the program and the hardware.

There is no floating-point unit. Other R3000A systems added one as a separate chip, the R3010. Sony’s CPU table lists none. The 3D maths goes instead to the GTE, which Sony describes as performing “fixed-point format matrix and vector operations”. Its rotation matrices hold 12-bit fractions: a value of 4096 means 1.0. One GTE command, RTPS, rotates a vertex, moves it into place and projects it onto the screen in 15 cycles, and the CPU can carry on with other instructions while it works. RTPT does three vertices, a whole triangle, at once.

The data cache is not a cache. In Sony’s words, “The D cache of the PlayStation is called a Scratch Pad.” It is one kilobyte of fast memory at a fixed address. An ordinary cache decides for itself what to keep; on the PlayStation the programmer decides what goes in the scratch pad, and so it is the natural home for the small tables a transform loop uses over and over.

Triangles, rectangles and textures

The GPU draws what the CPU and GTE hand it. The manual states: “The polygons handled by GPU are triangular and rectangular. Specify each vertex’s screen coordinates to draw.” Each vertex can carry its own colour, and the GPU blends between them (Gouraud shading).

Textures live in the same 1 MB of video memory as the picture, in the parts of a 1024 × 512 frame buffer that are not on screen, arranged as “texture pages” of 256 × 256 pixels. Between that memory and the GPU sits a texture cache of just 2K bytes. The manual advises that drawing is faster “when the polygons use textures of a size which can fit in the T-cache”, so the size of a texture was a speed decision as well as a memory one.

The sound system

Sony’s Table 4-1 gives the SPU in three lines: ADPCM samples, 24 simultaneous voices, 44.1 kHz. The voices change pitch and envelope under hardware control, so music does not need a stream of writes from the CPU. The samples sit in a separate 512 KB sound buffer that “is not mapped in the CPU address space”, and part of that buffer doubles as the work area for a hardware reverb.

CD audio goes through the same path. The manual says the CD decoder’s output “temporarily enters the SPU, is mixed with the SPU output, and then becomes the final audio output via a reverb unit”. Streamed CD music and sound effects share the same mixer and the same reverb.

Net Yaroze

In 1997 Sony let the public program the machine. Net Yaroze (from a Japanese phrase Edge translated as “Let’s create!”) went on sale in the UK on 28 February 1997 for £550. Edge credited the idea to Ken Kutaragi. The kit was a black PlayStation that could run home-made programs, a serial cable to a PC or Mac, a CD holding a C compiler, a debugger, conversion tools and Sony’s own PlayStation libraries, and membership of a private website where owners swapped code and questions.

There were limits. Everything had to fit in the machine’s memory, “2Mb main RAM, 1Mb VRAM, and 512K sound RAM”, so there was no streaming from CD, and games could only be shared with other members. Readers wrote to Edge doubting it was worth £550. When the magazine caught up with Yaroze owners in 2000, several were working at Codemasters, Reflections and Sony’s European studios, and members’ games had appeared on Official PlayStation Magazine cover discs. “I didn’t know much about programming, but I taught myself C from a couple of books and within six months I had written my first decent game,” Nick Ferguson told Edge.

Later years

A smaller redesign, the PS one, followed in July 2000. According to public sources Sony ended PlayStation production on 23 March 2006. Retro Gamer reported the end of production that year and put the machine’s sales at “over 100 million units”. Sony’s own corporate figures give cumulative shipments of more than 102.4 million. Its successor, the PlayStation 2, used a PlayStation processor to run the older machine’s games.

Sources

Sony Computer Entertainment, PlayStation Hardware (1998): memory, the missing TLB, the OS ROM and the CPU table (p. 2-3); the GTE (p. 1-4); the GPU, VRAM, colour modes, polygons and texture cache (pp. 3-3 to 3-8); the SPU, CD audio routing and sound buffer (pp. 4-3 to 4-4).
Sony Computer Entertainment, Inline Programming Reference (November 1998): the GTE as coprocessor 2, its 12-bit fixed-point matrices, RTPS and RTPT (p. 1-16), the GTE programming guide and command cycles (pp. 4-3 to 4-5).
IDT, R3000A/R3001/R3051 product information (1991): the R3000A’s on-chip TLB and the separate R3010 floating-point accelerator.
Edge issue 17, February 1995: the Japanese launch, 100,000 units and the ¥37,000 purchase (pp. 6-7); “the hardware launch of the decade” (editorial); the history feature on the Nintendo partnership, Super Disc, the 1991 CES, the 200 prototypes, PS-X and developer sign-ups (pp. 57-59).
David Sheff, Game Over: Press Start to Continue, with new chapters by Andy Eddy (GamePress, 1999), pp. 378-384: the 1988 contract, the “sole worldwide licenser” announcement, Ohga’s calls, Lincoln’s and Olafsson’s words, the October 1992 agreement; and Andy Eddy’s added chapter on the later PlayStation, with Lincoln’s retrospective comment.
Edge issue 24, September 1995: the US price of $299. Edge issue 27, December 1995: the 9 and 29 September 1995 launches and the £299 UK price.
Edge issue 41, January 1997, pp. 68-77: Net Yaroze, its price, contents and memory limit. Edge issue 42, February 1997: readers’ letters on its price. Edge issue 92, Christmas 2000, “Generation Y”: Yaroze owners in the industry and Nick Ferguson’s words.
Retro Gamer issue 24 (2006), p. 7: end of PlayStation production, “over 100 million units”.
Sony Interactive Entertainment, corporate “Business Data & Sales” page, accessed September 2026 (web, secondary): PlayStation cumulative shipments “More than 102.4 million”. https://sonyinteractive.com/en/corporate/data.html
Wikipedia, “PlayStation (console)” (web, secondary): the PS one’s July 2000 release and the 23 March 2006 end of production. https://en.wikipedia.org/wiki/PlayStation_(console)