CTIA/GTIA

Description

CTIA ("Color Television Interface Adapter") / GTIA ("George's Television Interface Adapter") is a television interface chip. ANTIC directly controls most of GTIA's operations, but the 6502 can be programmed to intercede and control some or all of GTIA's functions. GTIA converts the digital commands from ANTIC (or the 6502) into the signal that goes to the television. GTIA also adds some factors of its own, such as color values, player-missile graphics, and collision detection.

CTIA artifacts in blue/green, GTIA in 400/800 artifacts in green/blue and GTIA in XL/XEs artifacts in red/blue.

It's said that all PAL GTIAs are missing one red color, which is substituted by doubled brown color. Indeed, my tests show, that first color (#1) and last color (#15) are very similar or same.

Latest PAL GTIAs from China have annoying bug in 'GTIA modes', where some bits are displayed with high luminance. I have one report of such chip, it's production week is 9120 (end of May 1991).

Catalogue numbers

CTIA

CO12295

GTIA

CO14889 PAL
CO14805 NTSC
CO20120 SECAM

Pinout


pinout
A0-A4address bus
D0-D7data bus
AN0-AN2ANTIC bus
Vcc+5V power
T0-T3joystick trigger inputs
S0-S3console inputs
PALPAL clock input
CAD3color delay line adjustment input (sometimes called DEL)
COLORcolor signal output
LUM0-LUM3luminance signal output
CSYNCcomposite sync output
/HALTfor synchronizing ANTIC & GTIA (when low and in HBLANK, pmg data on bus will follow)
VssGround
OSCmain oscillator input
F0Ofast phase 0 output
Ø2phase 2 input
CSchip select
R/Wread/write
. Back (c) 1998-2004 Jindroush Last modified: Mon Feb 17 12:21:56 2003