COMMODORE 128 / 128D My first & beloved computer :) (by Hayrettin YILDIZ) All information below come from my fond memories. OPERATING MODES: 1) C64 Compatibility Mode 64K RAM, Basic 2.0, 40 column text MOS 8502 CPU operated at 1 MHz 2) C128 Native Mode 128K RAM, Basic 7.0, 40 or 80 column text MOS 8502 CPU operated at 1 or 2MHz 3) CP/M Plus (3.0) Mode 128K RAM, CP/M 3.0, 40 or 80 column text Zilog Z80A CPU operated at 1 MHz CPU: Two microprocessors included: 1) MOS 8502 (6502/6510 derivative) Operates at 1 or 2 MHz Both C64 and C128 modes uses this CPU 2) Zilog Z80A Operates at 2 MHz CP/M Plus (3.0) mode uses this CPU Boots up the system MEMORY: 1) ROM: C64 Basic 2.0 ROM 8K C64 Kernal ROM 8K C64 Character ROM 4K C128 Basic 7.0 ROM 32K 2) RAM: 128K (2x64K RAM Banks) Expandable up to 1MB (16 RAM Banks) 3) I/O: 4K memory mapped I/O area interfaced to I/O chips (SID, VIC, CIAs etc) 1K Color Memory (for VIC chip modes) MMU: Controls up to 16 banks of 64K memory blocks With bank switching 1024K of total memory possible SOUND: SID 8581 (6581 derivative) Analog sound processor 3 independent sound voices 3 waveform (triangle, sawtooth, pulse) and a white noise 16 bit frequency resolution Approximately 8 octave sound pitch range ADSR volume envelopes 4 bit master volume register Voice modulation and filtering Reads potentiometer inputs (eg. paddles) from joystick ports Random number generator VIDEO: Two different & independent video chips included Both can operate simultaneously with two video outputs (one composite vide, one RGB) 1) VIC 8567 (Video Interface Chip) VIC II (6567/9) derivative Runs only at slow (1 MHz) mode 16 colors Composite Video & TV (RF) Output Signals 16K RAM mapped from main RAM (selectable 16K VRAM bank) Horizontal and vertical pixel based smooth scrolling (up to 7 pixels) Interrupt creation Sprite collisions Raster line compare Light gun latch 40x25 characters text mode Singlecolor mode: 8x8 pixel character resolution Multicolor mode : 4x8 pixel character resolution Each character set contains 256 character definitions (total 2K) 320x200 pixel hi-res graphics mode Each 8x8 pixel block can have different fore and background color 160x200 pixel lo-res multicolor graphics mode Each 4x8 pixel block can have 3 different colors and one fixed background color 8 MOBs (Movable Object Blocks, Sprites) per rasterline In hi-res single color mode: 24x21 pixel resolution In lo-res multi-color mode: 12x21 pixel resolution Collision detection with other sprites and background is possible Sprite-sprite (number based) and sprite-background priority is selectable 2) VDC 8564 (Video Display Controller): Runs at slow (1 MHz) and fast (2 MHz) modes RGBI Video Output Separate video memory (16K or 64K) accessible from 2 byte memory interface 80x25 characters text mode (16 colors & attributes) 640x200 regular graphics resolution 640x400 interlaced resolution Programmable resolutions (up to 720x512) & colour depths (up to 16 colors) INPUT/OUTPUT: Two CIA 8526 I/O chips included (Complex Interface Adapter) CIA 6526 derivatives (compatible) Keyboard, joystick, serial port handling Time of Day (TOD) clocks, precise time counters External Connectors: 1 Expansion port 1 User port 1 Serial port (up to 5 devices) 2 Joystick ports (9 pin) 1 RF port (TV Output, VIC chip) 1 Composite Video Output (VIC chip) 1 RGBI Video Output (VDC chip)