Atari 7800 board differences

[dodge ramman]

I bought another 7800 on ebay and it seems to work well except for some static in the sound I opened it and found this diode like this and wondered if this is normal and why is my other 7800 not like this! 

[+-^CrossBow^-]

What diode? You mean the resistor between the two ram ICs? That is actually pretty normal and I see more 7800s with that resistor in place than without. I've even de-soldered it on a few to add shrink tubing to that lead just because I don't like how exposed it is next to those pins.

 

I'm pretty sure both of my 7800s have that resistor in place and one of my 7800s is an old original '84 made unit.

 

BTW..I see you have C64 installed as well on your revision. Might want to clip one of the legs on that before buttoning it back up.

[dodge ramman]

Sorry its been a long day, yes I meant a resistor, thanks for pointing that out! whats the deal with the C64?

[+DrVenkman]

My A1-serial number unit has that resistor; my AT84 unit does not.

 

 

[Trebor]

3 hours ago, dodge ramman said:

...whats the deal with the C64?

C64 was added to later versions of the console to fix a compatibility issue with the 2600 port of Dark Chambers. 

Inadvertently, it may cause other compatibility issues.

 

Below, it has been highlighted in red from the picture you provided:

 

 

[dodge ramman]

Thanks guys I'll keep this in mind!

[Sean39]

Ok I am bring this up to everyone on this thread.

My Dad many years ago stored all his Atari parts in tubs of boxes.

My dad Atari 7800 with the serial number 000517 EP 264 has a board in it

but I am not sure if he has the correct board in it because I found an another

board of his. I am going to post pitures of both if you look on one of them you

will see a stamp of 264 on the RF module even though on the side of the RF module

is has a sticker with 8418 date code. What I notice on that board the traces are smooth while on the board he has in it looks like foil

traces. you will see this. There is a stamped  on the other RF module ,but I cannot tell what it is.

 

I just want the correct mother board in my dad unit one of these two is the correct one.

 

I will post additional pics of the back sides as well

 

 

Thanks

 

 

 

Edited March 5, 2020 by Sean39

[Sean39]

Ok Now I am posting pictures of the bottoms of the mother boards.

 

First picture will have an earlier date and the second picture has a date of 1 week later.

 

The question between all the photos I have posted which one is the correct one for the

serial number 000517 EP264. The one missing the chips I can fill it since my father stored

many 1984 chips back then for the 7800 console. I actually have a Maria chip with the date

code of 1984 in the 5th week. As well all other chips around the same period.

All the RAM Chips I have for the 7800 date from 1983.

Anyways take a look at these photos.

 

Ok one of these boards is the correct one to go into the early 7800

and I want to make sure the correct board is in it. I really need experts

who know the 7800 inside out to help me.

there is date codes also on the joy stick ports. I have only posted this up here

since Curt has been helping me also. I just want this right since this is a very low serial number in the EP series.

I also know the 7800 even low serial numbers do not sell for a lot of money. I just want this correct since it was my fathers.

When he did work for them under contractors. He was an electronic Engineer.

 

I want this correct so when I can get Curts module that I can use my dad 7800 with it. My dad brought this home

with no box, so what would the correct box have this came in if it had sold in 1984 ? My dad brought it home from work,

so no box ever existed for this console. I want a box for it from 1984.

 

 

Thanks

 

 

Edited March 5, 2020 by Sean39

[Sean39]

Ok I notice a small difference in boards.

 

The one that is populated with chips on it seems to be coated in clear epoxy.

The other board does not have the appoxy but it does have the word OAK stamped on it.

take a look. The un populated board say OAK on it and lacks the clear epoxy.

I only posted this here since I know there is a lot of people that know a lot about the Atari 7800

on this thread. Please look at this photo. Any help will be appreciated.

 

Well this may help also.

 

 

 

[Sean39]

Hi everyone

      I went back and change my Birth year on my profile. I saw alot of people went and checked and it was incorrect.

It is correct now.

 

Thanks

 

[+DrVenkman]

6 hours ago, Sean39 said:

I actually have a Maria chip with the date

code of 1984 in the 5th week. As well all other chips around the same period.

The MARIA chip in one of my 7800’s has a date code of week 23 1983 (!).

 

But @Shawn is right - this really isn’t the thread for that.

[leech]

32 minutes ago, DrVenkman said:

The MARIA chip in one of my 7800’s has a date code of week 23 1983 (!).

 

But @Shawn is right - this really isn’t the thread for that.

Ha, this one looks quite different.  Since my case for this one is knackered, I should see if I could design a 3d printed shell that fits with the XM integrated somehow.

[Sean39]

Hi

 

I see you choose the number after the V for your date. The date code is the first three digits.

I will show you why it is now.

 

you will see on my First chip it has 405 V 1840   If I went with the 1840 then My chip would have been made

in the 18th week 1940.  The 405 States first number is the year 1984 and the last 2 numbers are the week.

We are looking at a chip made in 1984 and week 5 th.

 

If we take the first 3 numbers on your Maria Chip 423 then Your Maria chip was made in 1984 of the 23rd week.

Also the Maria Chip did not go in to production till 1984 only proto types were made before 1984..

 

Take a look at my chip and you will see that the 1840 could never be a date.

 

The second chip I have is dated 422 on it that dates it from 1984 in the 22nd week

The numbers that change after the letter  V , I have been trying to figure out what those actually stand for.

 

VTI dated their Chips a little different . Hitachi did a different date code on the RAM chips as well.

they would have date codes like 3K1 or a 3M1. First number was the year then the  letter was the month and last digit was the week.

 

Anyways no Maria Chips were mass produced in 1983. Atari waited till 1984 to start this process.

Ok Well I will be done with this part since this is not the correct thread for this, but I do hope this did help out some.

Also this is Curt thread on his device ,so I will be done with this so we get back on the correct subject.

 

I also want to point out the other person Maria chip with the 809. That chip dates from 1988 in the 9th week.

 

Thanks

 

 

 

Edited March 5, 2020 by Sean39

[Sean39]

To everyone

 

    I see my post appeared back up on the Thread but I am still leaving still since it had been remove at some point.

I am sorry to all that may have been angry. I hope what information I did post was helpful on the Maria Chip.

Thank you for the ones who did help me.

If anyone has information on my dad mother boards Please PM me so we do not tie up this thread.

 

Bye For now.

 

Edited March 5, 2020 by Sean39

[HammR25]

 

2 hours ago, Sean39 said:

To everyone

 

    I see my post appeared back up on the Thread but I am still leaving still since it had been remove at some point.

I am sorry to all that may have been angry. I hope what information I did post was helpful on the Maria Chip.

Thank you for the ones who did help me.

If anyone has information on my dad mother boards Please PM me so we do not tie up this thread.

 

Bye For now.

 

 

We're not angry man.  Hope you can figure out which 7800 is the one your Dad used.

[Sean39]

My post were moved. and some even removed as well

 

Thanks

 

[Sean39]

5 hours ago, HammR25 said:

 

 

We're not angry man.  Hope you can figure out which 7800 is the one your Dad used.

Thank you

  I was just trying to get the correct board in the case since my dad had two boards and one of them is the correct one for the serial number

00517 ep 264.

 

At this point they are both very early boards and it may not make much difference which one goes into it.

 

They were both the earliest boards ever released for the atari 7800 system

 

thanks

 

 

 

[towmater]

What's up with all of the major chips being socketed?

[+-^CrossBow^-]

10 hours ago, towmater said:

What's up with all of the major chips being socketed?

The first released earlier unit have all the main ICs in sockets. Also not unusual to find 7800s with some of the chips in sockets and others not. I suspect the ones I've seen with sockets on like the RIOT or TIA..etc were likely refurbs from Atari sent back and reparied and then released back into the wild as new units. That is how mine apparently was done as it is a fully sockets early made 84 unit but my folks bought in 88 in the newer style box. But the chips etc inside would all seem to indicate it was made originally in '84.

 

Honestly it is tough to know because it is apparently with the 7800 that Atari was literally using whatever was on the shelves to be found to kick these things out. That is why we find older '84 style boards with expansion slots shoved into later made 87/88 cases without the expansion port hole on the side and other oddities.

 

[Shawn]

On 3/5/2020 at 6:47 PM, Sean39 said:

My post were moved. and some even removed as well

 

Thanks

 

 

That is because you keep spamming multiple threads in this forum with the same "my dad's atari 7800" posts, over and over and over.

[Sean39]

Hi I was not trying to Spam anything. I was just trying to get help with this subject.

Sorry if I caused any problems of any sort.

 

As I said in the other thread I was not going to make anymore post.

I have not been on that thread at all since then. I have already apologized and really meant it.

 

Thanks

 

[Sean39]

13 hours ago, Shawn said:

 

That is because you keep spamming multiple threads in this forum with the same "my dad's atari 7800" posts, over and over and over.

I saw you message. Do not worry I will not write you anymore. I was just trying to apologize for the many post I made.

 

Thank you

[Shawn]

1 hour ago, Sean39 said:

I saw you message. Do not worry I will not write you anymore. I was just trying to apologize for the many post I made.

 

Thank you

 

You mean the reply I sent to your PM. Correct, you cannot message me as I have you blocked. Why you continued in this thread about that I have no clue. Take a hint, I don't want to talk to you. I wouldn't have said so publicly but if that is what you where looking for then here it is.