TenoxVGA ECL to VGA Adapter (ECL2VGA)

TenoxVGA is an adapter that lets you use a standard LCD flat panel or a CRT monitor with Atari TT built-in video card in TT-HIGH mode (1280x960). You can think of it as TTM194 or TTM195 monitor replacement or ECL to VGA video signal converter.

The Atari TT traditionally lets you use VGA monitors in ST and TT low to medium resolutions. The maximum resolution you can get on a standard monitor or a flat panel is 640x480 with a rather large white border around. In order to go any higher than that you need to have a special ECL monitor such as TTM194 / TTM195, or a VME bus graphics card. These are nowadays rather hard to come by. This project was conceived to fix this issue. The adapter is a full signal conversion from ECL to VGA and allows you to use any standard VGA monitor or flat panel.

The adapter plugs in directly to the Atari TT monitor port and switches the computer in to TT-HIGH mode. Just connect your standard LCD panel or CRT monitor, no drivers, configuration changes or opening the case / soldering required. TenoxVGA requires a 12V external power supply to operate. It is possible to draw power from TT internal PSU by using Y splitter cable for HDD power. Also the device plugs directly to Atari TT video port which requires some additional space on back of the computer.

The adapter produces a remarkably sharp and clear picture on most CRTs (pictures coming soon). On LCD monitors, the image quality can vary depending on the adjustments provided on your monitor and the quality of the internal scaler. LCD's with a native horizontal resolution of 1280 pixels will be best as you can achieve a 1:1 horizontal pixel mapping. The vertical quality will depend on how your monitor maps the Atari's 960 pixel field to the panel res. Best results are obtained on a 1280x1024 panel having a menu setting to disable video expansion, providing a 1:1 vertical pixel mapping.


To order, email me at: orders@legacypixels.com


Item Notes Price US$

(12 Feb 2024)

ECL2VGA Adapter Assembled & Tested


In Stock
12v Power Supply 120v US Plug


In Stock
3D Printed Case Color Choices


Print to Order

Technical Specifications

Input Port: Atari TT HD-15 D-Sub Video port
Output Port: Standard VGA HD-15 D-Sub port
Resolution: 1280 x 960
Colors: 2 (BW), 1 BPP
Aspect ratio: 4:3
H. Sync: 71.911 KHz
V. Sync: 71.624 Hz
Power Source: external 12V DC, Center Positive
DC Power Plug: 2.1mm ID x 5.5mm OD x 9.5mm plug 
Case Dimensions: 85mm x 41mm x 21mm

Screenshots (NEC 1980SX)

Tested Monitors:

Monitor Type Expansion Control Comments
HP p1230 Trinitron CRT N/A Looks great
Sony MultiScan E400 Trinitron CRT N/A Pending
NEC MultiSync 1980SX(i) 19" LCD 1280x1024 YES Looks Fantastic
NEC MultiSync 1990SX(i) 19" LCD 1280x1024 YES "Even better than [the] 1980"
NEC MultiSync 195NXm LCD NO Good, some Horiz banding
Hanns-G HC194D LCD NO Good, some Horiz banding
NEC MultiSync EA190m LCD NO Good, some Horiz banding
HP f1905 19" LCD 1280x1024 NO Good, some Horiz banding, scaler is pretty good
NEC MultiSync 1970NX 19" LCD 1280x1024 NO Decent, some Horiz banding
NEC MultiSync 1970VX 19" LCD 1280x1024 NO Decent, some Horiz banding


To order, email me at: orders@legacypixels.com


The TexnoxVGA ECL2VGA board was designed by tenox (Antoni Sawicki) and is reproduced here with his permission.
Copyright © 2013 by Antoni Sawicki as@tenoware.com

Antoni's TenoxVGA GitHub Page

Page background by SVGBackgrounds.com