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A unique 2600JR?


Benzman66

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So far I think only two have been found? The original post and the one I sent to Longhorn correct? They are fairly uncommon.

 

And LittleJoe - -

 

http://www.atariage.com/forums/topic/196368-unicorn-boards-and-harmony-cart-menus-single-chip-2600-compatibility/page__view__findpost__p__2498702

 

And, AtariJoe - -

 

http://www.atariage.com/forums/topic/180077-atari-2600jr-unicorn/page__view__findpost__p__2261133

 

 

I'd say they are more common than we know, it's just that most folks don't crack 'em open and find out!

 

The ability to build-in a 4k or 2k mask ROM, however, makes these VERY cool!

 

The one I just did up with PITFALL built in is a lot of fun!

 

-a2a

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As for the "cracking" them open. In allot of cases the stems and shells are very weak. I've broken allot of Jrs opening them up.

 

Yup, the old plastic gets very brittle on some of them, leading to spontaneous shattering!

 

Luckily, the newer Jrs. seem to have better plastic? I was having issues with the "short rainbow" Jrs., but the "long rainbow" ones are mostly okay, except for the annoyance of those pesky tabs that hold the top and bottom shell together . . . hate those! :)

 

Now that we know the graphical "glitches" to watch for on certain cartridges with these single-chip units, though, with the HARMONY and PITFALL II, for example, no one needs to crack 'em open . . . unless they like to tinker, like me! :D

 

-a2a

Edited by atari2atari
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  • 4 weeks later...
Nothing definitive but it seems like serial number that begins with A19 are those made in 1990's and would have a single chip board.

 

But, it's always worth cracking it open and taking a look! Or, at least, that's my philosophy as a hardware guy! :)

 

-a2a

 

OK, I was trying to open mine up but it is impossible to get the plastic covers apart at the front. There are some clips which I was not able to handle and I did not want to break the thin plastics so I gave up. Anyway I am 99% sure I have the "standard" Junior with 3 chips because I did see those parts circled on the picture when I was trying to open it. There definitely more resistors (?) in mine like in those regular Juniors, note Unicorn has less, also that big fat cap and grill pattern - all inside mine. And of course there is a huge metal shielding covering all insides...

 

2rw45yx.jpg

 

btw I think mine was also made in 90s.

Edited by maiki
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Yeah, those little plastic clips are a MENACE, I agree! A small screw-driver and some finesse are needed to make it happen. It's a pain, I won't disagree!

 

You might be right, however, based on the observations you pointed out that others have made - - you might just have a regular Junior.

 

Still an ATARI, though, and still fun! Enjoy it . . . :)

 

-a2a

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  • 6 years later...

That is a known (rare) version of the Junior motherboard. Benjamin Heckendorn attempted to use one of those for his very first portable VCS project, but accidentally fried it and couldn't find another. His old website detailing the attempt may still be on the web. There are some possible small sacrifices to be made if using such a board/chip, though: like all PAL VCSes, the 1-chip Jr. has only a single audio output, so a "stereo" mod is impossible. It probably can't use the recently-developed pause switch mod either.

 

Came across this chip while sorting junk bins after shop move.

 

Just did a Google hangout with Parker Dillmann to cross-reference the pinout since he has one of these as well (the schematics online are inaccurate)

 

It still works! Not fried after all. Now I can finish that super portable I started back in 2001...

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Hey, nifty!

 

I will be interested to read the build-log !

 

I'm sure it will be a better 2600 portable than the ones I have seen in the stores recently !

 

I still have my board, but never got around to adding a ROM into the blank slot.

 

Mostly because I couldn't figure out how to design a pull-up resistor that would turn OFF the soldered-in ROM when a REAL cartridge was slotted in!

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Since Ben himself brought this back up, I've wondered if Kool Aid man has been tested on these? We already know there are some graphic glitches that aren't game breaking, but that also means the embedded TIA is different and I wonder if it has the same collision detection issues in Kool Aid main that is known on later make TIA ICs?

Edited by -^Cro§Bow^-
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  • 1 year later...
On 4/14/2010 at 4:32 AM, A.J. Franzman said:

That is a known (rare) version of the Junior motherboard. Benjamin Heckendorn attempted to use one of those for his very first portable VCS project, but accidentally fried it and couldn't find another. His old website detailing the attempt may still be on the web. There are some possible small sacrifices to be made if using such a board/chip, though: like all PAL VCSes, the 1-chip Jr. has only a single audio output, so a "stereo" mod is impossible. It probably can't use the recently-developed pause switch mod either.

Turns out he didn't fry it. He actually completed his project, 19 years later:

https://www.benheck.com/atari-2600-junior-single-chip-portable/

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  • 1 year later...
On 4/14/2010 at 12:45 PM, Benzman66 said:

 

Here are the numbers, in exact order as printed;

C101688-002

ATARI 1987

RP2A10

38 BL2 46

 

This system looks like it was never used, the board is perfect and the housing looks new. I couldn't even find a scratch! Works great. I was going to keep for myself, but wonder what it would be worth if I listed it since it is a rarity? Maybe I could be the next "Tanner?" LOL.

 

I found this post while trying to figure out these numbers. I own 2, all the numbers are exactly the same except for the last. I have:

38 BL2 48

38 BL2 49

 

The Rev 3 board LittleJoe owns has a different chip. It's hard to read but looks like

C101688-001

ATARI 1987

RP2A10

38 7CE 53

 

That 38 could be a 24. The E in 7CE could be a 1 or an L or I maybe. The 3 in 53 is also blurry.

Edited by skintigh
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