TenoxVGA is an adapter that lets you use standard LCD flat panel or 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.

tt with ttm195 Atari TT traditionally lets you use VGA monitors in ST and TT low to medium resolutions. The maximum you can get on a standard monitor or flat panel is 640x480 with rather large white border. 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. There are few other projects that convert ECL to TTL signal. Unfortunately they only allow non-Atari ECL CRTs such as EIZO to be used in TT-HIGH mode. This 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. A wall adapter is available as an option. The device plugs directly to Atari TT video port which requires some additional space on back of the computer possibly blocking the printer port. If this is a problem we also sell a short VGA cable that can go between Atari and the adapter.


Technical Specifications:

    Input PortAtari TT DSUB Video port
    Output PortStandard VGA 15 pin DSUB
    Resolution1280 x 960
    Colors2 (BW), 1 BPP
    Aspect ratio4:3
    H. Sync71.911 KHz
    V. Sync71.624 Hz
    Power Sourceexternal 12V DC, Centre Positive
    DC Power Plug2.1mm ID x 5.5mm OD x 9.5mm plug 
    Case Dimensions85mm x 41mm x 21mm

tt LCD LCD Panel compatibility:
TT-HIGH mode is 1280x960 pixels. Most LCD panels are made to operate in 1280x1024 resolution. This makes a 64 pixel difference vertically and 4:3 to 5:4 aspect difference. For the best image quality you should use an LCD flat panel with 1:1 pixel mapping mode. This setting is sometimes called scaling off, expansion off, 1:1 wide mode, or 1:1 aspect mode. If you don't turn on 1:1 mode or disable scaling / expansion, the display will be scaled out of aspect and anti aliased. If your LCD panel doesn't support this setting you may need to try a different monitor. TenoxVGA was tested with many different LCD panels. TT-HIGH looks remarkably good even in anti aliased mode as long as is in aspect.

The device is manufactured and shipped from USA. International buyers and shipping welcome! The pricing is included in table below. We also offer UPS or FedEx shipment if required.

Warranty Return policy:
This is a hobby project and a nonprofit, noncommercial operation. Due to a low quantity and very high cost to manufacture we cannot accept any returns. If your unit is DOA we will exchange it for a working one. If your LCD panel or CRT monitor will not work perfectly in Atari TT-HIGH mode we will try to assist you to correct the situation but we cannot accept a return. All sales are final.


    Item USD
    TenoxVGA ECL2VGA Adapter $165
    Optional 12V Power Supply $30
    Optional Short VGA Extension Cable $10
    Shipping USPS (registered) $30

All prices are in US Dollars. The non-USD prices are only approximate guidance and will be calculated by PayPal upon payment.

Q: Will it work with my random LCD panel?
A: Yes, but the display may be anti aliased, out of aspect, or have other issues. You need to use an LCD panel with 1:1 pixel mapping / expansion mode off. You may need to try different LCD panel. If you want to buy just one that does work 100%, you should invest in a NEC 1990 SXi. They often pop up on eBay for $50. Following page from NEC user manual will give you some idea what may be wrong and how to adjust for it.

Q: What is the image quality?
A: With correct settings (scaling/expansion disabled) the image will look EXACTLY like the Mono / High mode in ST emulator.

Q: Can I see a picture of the display up close?
A: Here is a picture of The Desktop, Cubase and Calamus on Atari TT with NEC 1990 SXi monitor. And the desktop up close. And Cubase full screen.


Q: Can I see pictures of it working with different monitors?
A: Sure! Emachines, Acer, NEC 1760. Note that moire on the monitor comes up from the camera digital sensor itself. It's not visible with a naked eye.

Q: Is ECL2VGA adapter better than VME card?
A: No. For many reasons you are better off with a VME graphics card, if you can get one and have an empty VME slot.

Q: Is there a case for the adapter?
A: Yes, the adapter comes in a 3D printed case. It's not the best quality but it's better than no case or a shrink wrap.

Q: Can the device be produced by Lotharek or Inventronik?
A: Unlikely. The total market for ECL2VGA adapter is estimated 50 users worldwide (25 UK / 25 Germany), and that's if the price was under $100. Unfortunately the price is higher, so even less users will buy. If this was 500 or 5000 users it would be a different story. I spoke with Mr Wolfgang Forster and at least for now he has other priorities.

Q: Can I get one to try before I buy?
A: No, this is just a hobby project, we have no resources to do that.

Q: Equivalent Power Supply in Europe?
A: Sure: UK, Germany


Purchasing TenoxVGA:
Available through an instant PayPal checkout. Shipping will be to the PayPal specified address, so make sure it's correct. Order is subject to stock availability. If the adapter, power supply or short VGA cable is out of stock you will have to wait (we will send you a notification).

If ordered, the 12V power supply will come with a plug based on your shipment address. US, UK, German and Australian plugs available. The VGA short extension cable is needed if you don't have enough room on back of your Atari.

PayPal won't let me specify the quantity. If you are planning to purchase more than 1 device please email me instead. There are cheaper shipping options but you will be voiding insurance and tracking number.

ac plugs

ext cable


Currently TenoxVGA is out of stock. Send me an email and I'll add you to the waiting list for next batch.


Copyright © 2013-2019 by Antoni Sawicki <as@tenoware.com>
The device was designed and is manufactured by MSDUS.
Atari Font by Rudolf Polzer with permission from Atari Inc.
This is a nonprofit, noncommercial, hobby project.
TenoxVGA is now an open source project available on GitHub.