|
|
|
\documentclass[11pt]{article}
|
|
%Gummi|065|=)
|
|
\usepackage{graphicx}
|
|
\usepackage{caption}
|
|
\title{\textbf{Commodore 1902A Repair}}
|
|
\author{Steak Electronics}
|
|
\date{}
|
|
\begin{document}
|
|
|
|
%\maketitle
|
|
|
|
|
|
\includegraphics[scale=0.4]{../pics/DSCN1699.JPG}
|
|
\captionof{figure}{Commodore 1902A 14'' CRT Monitor}
|
|
|
|
\section{Overview}
|
|
The goal is to repair an old Commodore computer monitor. This particular monitor, the 1902A has two inputs. One for composite, and one for a mode which the C128 must run in, in order to produce video output for C64 compatibility mode or something. I'm not really sure. (todo). This means RGBI input must work.
|
|
|
|
Currently, the monitor has errors on both RGBI input, as well as composite input. This means that the errors are likely common to both signal paths.
|
|
|
|
\tableofcontents
|
|
|
|
\section{Work Log}
|
|
I picked up an old HP TV service manual (6945A) for this project. I am not knowledgable about televisions, but the more I read, the more I think I can handle this. I have also the manual for the monitor, though it is quite a bit sparse, comparably.
|
|
|
|
|
|
Quite a bit of the Commodore 1902A TV circuitry (H sync, V sync, etc) is in a few ICs.
|
|
|
|
|
|
The waveforms in the Commodore manual were created with a (standard?) NTSC test signal, the \textbf{10 bar gated rainbow pattern signal}. I am currently researching how to generate that myself, without forking out the cash for a video tester (Cheapest I saw the other day was \$70. I wouldn't pay more than \$20.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\end{document}
|
|
|