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)