What does your monitor display? If nothing, try to switch one DIP after one until you get a display.

RCA jacks are not connected until you intall something to the feature connector.

And if it does nothing your ROM is most likely corrupted, you should cover the window asap...

Found the chipset data sheet. It appears those cards were used in some early Zenith systems from what little Google delivered.
I have a diff Chips EGA card (Ahead branded) with composite outs and it will output composite without anything attached to the feature connector.
https://datasheetspdf.com/pdf/631612/Chips/82C431/1

x86 Heath/Zenith hardware/sytem documentation is literally unobtainium unless you get the manuals with the components/systems.

Caluser2000 wrote on 2021-01-10, 16:06:

x86 Heath/Zenith hardware/sytem documentation is literally unobtainium unless you get the manuals with the components/systems.

aww

SammyFox wrote on 2021-01-10, 12:21:

I bought this thing on ebay and it's arrived but I can't find any documentation for it and I wanna know what the dip switches do and what the rca jacks are used for. The model is Heath 150-303.

Most EGA cards follow the IBM EGA DIP switch settings, as there is software that reads the DIP switches directly from the hardware, so the BIOS doesn't necessarily have a chance to map proprietary switch settings to IBM compatible configuration numbers. Thus trying to treat the DIP switches like you had an original IBM EGA works more often than not.

A single RCA jack on CGA cards always has a composite base-band video signal. This signal is grayscale in modes 0/2/5/6 and has NTSC color in modes 1/3/4. There are a lot of clone CGA cards with two RCA jacks where one of the RCA jacks always carries a grayscale signal. This results in a sharp image on grayscale monitors even in modes 1/3/4. For EGA cards, the situation is more difficult. The 350-line EGA modes do not have TV compatible timing, so the RCA jack is usually useless in 350-line modes. In 200-line modes, the two jacks might behave just like on CGA cards with two jacks, but (as people already mentioned in the thread) on a lot of EGA clones, the circuitry to generate a composite video signal is not included, and the RCA jacks are just connected to some pins on the feature connector, where an optional composite video generator might get installed (although I have to admit i've never seen one - on the other hand, I didn't specifically search for them).

mkarcher wrote on 2021-01-10, 20:14:

For EGA cards, the situation is more difficult. The 350-line EGA modes do not have TV compatible timing, so the RCA jack is usually useless in 350-line modes. In 200-line modes, the two jacks might behave just like on CGA cards with two jacks, but (as people already mentioned in the thread) on a lot of EGA clones, the circuitry to generate a composite video signal is not included, and the RCA jacks are just connected to some pins on the feature connector, where an optional composite video generator might get installed (although I have to admit i've never seen one - on the other hand, I didn't specifically search for them).

I have one...
TSENG EVA/480 ET-2000 EGA / NEC GB-1 COLOR GRAPHICS BOARD
...and never saw an EGA card where composite out is working without a board on the feature connector.

Predator99 wrote on 2021-01-10, 20:36:

I have one... TSENG EVA/480 ET-2000 EGA / NEC GB-1 COLOR GRAPHICS BOARD ...and never saw an EGA card where composite out is work […]
Show full quote

mkarcher wrote on 2021-01-10, 20:14:

For EGA cards, the situation is more difficult. The 350-line EGA modes do not have TV compatible timing, so the RCA jack is usually useless in 350-line modes. In 200-line modes, the two jacks might behave just like on CGA cards with two jacks, but (as people already mentioned in the thread) on a lot of EGA clones, the circuitry to generate a composite video signal is not included, and the RCA jacks are just connected to some pins on the feature connector, where an optional composite video generator might get installed (although I have to admit i've never seen one - on the other hand, I didn't specifically search for them).

I have one...
TSENG EVA/480 ET-2000 EGA / NEC GB-1 COLOR GRAPHICS BOARD
...and never saw an EGA card where composite out is working without a board on the feature connector.

Won't that sub board be on the equivalent of a feature connector?

Caluser2000 wrote on 2021-01-10, 21:21:

Predator99 wrote on 2021-01-10, 20:36:

I have one... TSENG EVA/480 ET-2000 EGA / NEC GB-1 COLOR GRAPHICS BOARD ...and never saw an EGA card where composite out is work […]
Show full quote

mkarcher wrote on 2021-01-10, 20:14:

For EGA cards, the situation is more difficult. The 350-line EGA modes do not have TV compatible timing, so the RCA jack is usually useless in 350-line modes. In 200-line modes, the two jacks might behave just like on CGA cards with two jacks, but (as people already mentioned in the thread) on a lot of EGA clones, the circuitry to generate a composite video signal is not included, and the RCA jacks are just connected to some pins on the feature connector, where an optional composite video generator might get installed (although I have to admit i've never seen one - on the other hand, I didn't specifically search for them).

I have one...
TSENG EVA/480 ET-2000 EGA / NEC GB-1 COLOR GRAPHICS BOARD
...and never saw an EGA card where composite out is working without a board on the feature connector.

Won't that sub board be on the equivalent of a feature connector?

Some EGA cards have the extra parts and support for composite out, my Vtech Auto EGA4+ does and it works as have tested it on my little old TV. My Paradise EGA Auto 480 has composite but they do not work at all but the manual also says so....

Ok so I don't have the extra little board thing, but is there like a composite to cga/ega converter? because the monochrome monitor I already have is alright, but I also have an amdak composite monitor that's got a beautiful amber phosphor and I'd love to use on the computer.