Returning to the 7800 fold - question about the so-called "expansion interface" and its original function

[BIGHMW]

I already had re-acquired the 7800 ProSystem a few months ago and will first buy another power supply as it seems like the console will sometimes power on or not as to try to save a few bucks vs. shipping it out only to then find out that it only needed a new power supply in the first place, but, my unit is kinda unique, it has an open hole, in which, after doing research on it, was supposed to have been for the "expansion interface", and so, I found yet another 7800 with the such interface already wired in on it on eBay.

 

Now my question is, before I buy it, what is/was its original intended function and is that function still relevant here in 2023??? Note that I already do have a 7800 with a near-mint, unscratched bezel (it did come with the plastic film on it that I have since removed) and can easily switch it out and put it on this console instead, I'm almost out of the debt I've been in, but will hold off first before buying it until I am well in the clear.

 

https://www.ebay.com/itm/285109832289?hash=item4261deca61%3Ag%3AUXkAAOSwZcZjw39y&amdata=enc%3AAQAHAAAAoAHnHuwAs6MvI9sVTuo%2BAm374ZcPcPflwOSVxr%2BIn2gFw%2BY%2BzkeweXfSxMXHNFuM%2BxBJAeutEepqnSc9vLUJpGRuBkbDk3gXCdzQPYm12y9THJAsezTryQXsw%2FfAdEQe6yzc6TMuRwOXQyoOiK8QEj%2Bjtfbsocnw75D9hpalNZuPjUsqndx9JIRFCX3EJsvDNR7hnxD1sLBGBQdl3%2FdPSug%3D|tkp%3ABk9SR8zD8pW6YQ&LH_BIN=1

 

 

 

[+karri]

From the 7800 wiki:

After the acquisition of the Atari Consumer Division by Jack Tramiel in 1984, several expansion options for the system were cancelled:

• The expansion port, to allow for the addition of a planned computer keyboard and connection to laserdisc players and other peripherals, was removed in the second and third revisions of the 7800.^[37]

[+Muddyfunster]

There are a million threads about the expansion port already, just search "7800 Expansion Port".

 

13 minutes ago, BIGHMW said:

is that function still relevant here in 2023

No it is not.

[John Stamos Mullet]

Nothing. Nothing uses it.

 

Also - Google exists.

[madmax_2069]

The only thing I seen it used for so far is this 

 

 

 

 

 

Edited January 21 by madmax_2069

[Shawn]

16 hours ago, madmax_2069 said:

The only thing I seen it used for so far is this 

 

 

 

 

 

 

I made an MP3 player box that plugged into the expansion port so it played the "have you played atari today?" jingle while the 7800 bios booted. It was a one off "just cause I can" kinda thing. There might be pictures or a video of it in action here on the forum. It wasn't much but it was an expansion port device  At one time CPUWIZ was experimenting with doing much more than I ever could with sound and more via the expansion port. Dunno if any of that was posted publicly or not.

[+x=usr(1536)]

4 hours ago, Shawn said:

At one time CPUWIZ was experimenting with doing much more than I ever could with sound and more via the expansion port. Dunno if any of that was posted publicly or not.

He hinted at some of it, but I don't believe that he ever directly described exactly what it was that he was putting together.

[jerseystyle]

On 1/20/2023 at 3:08 PM, BIGHMW said:

I already had re-acquired the 7800 ProSystem a few months ago and will first buy another power supply as it seems like the console will sometimes power on or not as to try to save a few bucks vs. shipping it out only to then find out that it only needed a new power supply in the first place, but, my unit is kinda unique, it has an open hole, in which, after doing research on it, was supposed to have been for the "expansion interface", and so, I found yet another 7800 with the such interface already wired in on it on eBay.

 

Now my question is, before I buy it, what is/was its original intended function and is that function still relevant here in 2023??? Note that I already do have a 7800 with a near-mint, unscratched bezel (it did come with the plastic film on it that I have since removed) and can easily switch it out and put it on this console instead, I'm almost out of the debt I've been in, but will hold off first before buying it until I am well in the clear.

 

https://www.ebay.com/itm/285109832289?hash=item4261deca61%3Ag%3AUXkAAOSwZcZjw39y&amdata=enc%3AAQAHAAAAoAHnHuwAs6MvI9sVTuo%2BAm374ZcPcPflwOSVxr%2BIn2gFw%2BY%2BzkeweXfSxMXHNFuM%2BxBJAeutEepqnSc9vLUJpGRuBkbDk3gXCdzQPYm12y9THJAsezTryQXsw%2FfAdEQe6yzc6TMuRwOXQyoOiK8QEj%2Bjtfbsocnw75D9hpalNZuPjUsqndx9JIRFCX3EJsvDNR7hnxD1sLBGBQdl3%2FdPSug%3D|tkp%3ABk9SR8zD8pW6YQ&LH_BIN=1

 

 

 

There were plans for a keyboard attachment, a laserdisc player, etc. nothing ever came of it though. Ah, what could’ve been…