PlayStation System Overview
CPU: Customized MIPS R3000A 32-bit RISC CPU (might be based on the LSI L64360 embedded CPU)
- Clocked at 33.8MHz.
- 32 32-bit general purpose registers (35 total if special hi, lo and pc
registers are included, first register locked to zero).
- 4KB I-cache.
- 1KB D-cache repurposed as fast 'scratchpad' memory.
- Geometry Transformation Engine (GTE) for 3D vector calculations
(accessed as cop2).
- No hardware floating point unit.
Graphics: Custom GPU
- Clocked at 33.8MHz (same as CPU, may need verification however).
- Supports display resolutions of 256x240 to 640x480 for NTSC and 256x256
to 640x512 for PAL (272 vertical lines is apparently possible for PAL as well).
- Supports displaying in 16-bit or 24-bit color depths (GPU only draws
primitives in 16-bit).
- RGB555 pixel format (32K colors total) with mask bit for
transparency/write protect masks.
- 1MB of VRAM (connected to GPU with 16-bit memory bus, not directly
accessible by CPU).
- 2KB texture cache.
- Flat and shaded lines and polylines of up to virtually unlimited points.
- Fixed sized (1x1, 8x8, 16x16) and variable size flat and textured
- Flat and textured 3-point and 4-point polygons with optional shading
(quads are drawn as two triangles).
- Supports 4-bit, 8-bit and 16-bit textures. 4-bit and 8-bit textures
use color lookup tables or CLUTs as palettes.
- 4 semi-transparency blending modes.
- 24-bit color processing with final output converted to 16-bit with
optional dithering (flawed on old 160pin GPUs resulting in banding
on shaded textures).
- GPU draws entirely in 2D resulting to affine distortion and various
depth clipping issues.
- VRAM addressed as a 1024x512 16bpp framebuffer divided into
32 64x256 pixel pages (when texture mapping). Used for display/draw buffers,
textures and CLUTs.
Sound: Custom SPU
- 24 voices with ADSR, pitch and modulation parameters.
- Noise generator on any of the 24 voices.
- 512KB SPU RAM (not accessible by CPU).
- 44.1KHz mixing rate.
- Only supports ADPCM samples with loop start and loop end flags.
- Hardware reverb with programmable reverb registers.
- CD-ROM digital audio input and external digital audio input via expansion port.
CD-ROM: 2x speed CD-ROM drive
- Roughly 300KB/s maximum read speed.
- Wobble groove based disc authentication scheme (easily defeated by
- Supports CD-DA and CD-XA ADPCM audio playback.
- Hardware ADPCM decoder for CD-XA ADPCM audio tracks.
- CD-XA ADPCM sample rates of 18.9KHz or 37.8KHz in Mono or Stereo.
- Up to 32 ADPCM streams per CD-XA track (one channel at a time in
playback, channel switching possible during playback).
- Supports simultaneous CD-XA playback and data streaming (commonly used
in FMVs in conjunction with the MDEC).
- 2MB DRAM (first 64KB of RAM used by system kernel).
- 1MB VRAM.
- 512KB SPU RAM.
- 512KB BIOS ROM.
- Expansion ROM via expansion port up to 512KB supported (in default mapping).
Storage: Memory Cards
- 128KB total capacity.
- 1 block is 8KB each.
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