A little background.
Many many years ago, I purchased a used NES (complete with controller and pack in game) from someone for $5. It was great except for one problem, the RF out did not work. Switch box worked fine. The A/V out worked perfect, but the poor NES just could not output RF for some reason on any TV. But for a kid with no allowance or job, this was a minor point and a nice steal.
Not long after, I began to explore electronics. Without a lot of guidance, I took apart a lot of junk and piled them outside. I also started getting catalogs from a number of companies. One in particular sold a lot of surplus "junk" for madly cheap prices. $1 for a sandwich bag full of random LED's weren't uncommon (these were the low grade crappy kind, not the high output kind we're used to now). While flipping through the newest catalog there was a new section dedicated to "parts boards" with short descriptions of what they contained. One in particular caught my eye, a "parts" board for less than $5 that sported an RF modulator.
Not really understanding that not every RF modulator is built the same, I dug into my birthday money and ordered it. A week later it arrived and too my disappointment, the RF "box" wasn't even the same size.
I had no idea how to remove the box to even try and never bothered. I packed it away in a box and kept it in deep storage ever since, only to surface on occasion during moves.
Fast forward to today and I present to you, "Mystery PCB".
I have a fairly good idea, in some small part, what it is but there are some puzzles about it. Besides the usual part markings and IC markings there is only one manufacturers mark on the PCB,
INTV 1988. First clue, INTV is a common abbreviation for Intellivision. Great! Hit up Google and start looking at those PCBs.... uh... wait.... 1988? Intellivision was discontinued in 1984 according to Wikipedia.
Hhmm.... But check this page out.
http://www.the-liberator.net/site-files/retro-games/hardware/Intellivision-1/intellivision-1-1981-kalex.htm
Wow... that Kalex board looks like the predecessor to what I have..... No need for pictures to show that the bottoms on both are virtually identical. Right down to the holes... except mine doesn't say Kalex anywhere..... For the curious, I have a part number stamped into the heat sink
Part. No. 2609-4479 REL A Google search turns up Miley Cyrus porn for some reason.
After changing my Google search settings, I forge ahead.
The top side has some uncanny matchings. There's the headers on the left and right, the RF modulator, the slide switch. All in the appropriate places. The winged thing on the left is a 7805, a well known voltage regulator, right where that daughter board on the Kalex is located. Another search on the same site turns up yet another artifact, an
INTV System III with a date of 1980. Same layout.
However all the ICs are smaller, there is a "potential" 1988 date and 68 pin socket at the top. No, that socket wasn't populated when I got it.
That socket... obviously for a CPU.... OK, Wikipedia what can you tell me? The CPU in the Intellivision was a CP1610.
Here's what Wikipedia has to say about it.Production of the CP1600 ended in 1985 when General Instruments spun off its microelectronics division to create Microchip Technology. By this point a number of 32-bit designs like the MC68000 were available that limited interest in a 16-bit design like the CP1600, and their main existing customer, the Intellivision, was no longer in production. Many other products were also end-of-lifed at the same time, and their primary product was the PIC.
Microchip? What a coincidence, three IC's on the board are marked as Microchips.
One is labeled as GROM... Graphics perhaps?
One is labeled WBEXEC....
The third IC, marked as CP 1610... woah.... Is that the actual CPU there?? Hmmm... that means the socket isn't for a CPU I guess....
wait..... EXEC? Intellivision 3 was equipped with a lockout chip (kind of like NES 10NES)... that was named EXEC... But I3 was canceled according to Wikipedia... or was it?
At this point I'm absolutely positive that I have some type of Intellivision console PCB but which one??
The Liberator reveals nothing more so another Google search is in order and I'm lead to
http://www.intellivisionlives.com/bluesky/hardware/intelli3_tech.htmlWhich mentions
The unit, which is subject to FCC certification, will be compatible with all Intellivision and Intellivision II cartridges as well as Intellivision II add-on modules such as the Entertainment Computer System.
Interesting...... However, it mentions IC's such as a STIC (GPU) and an audio chip that are notably missing. Is that what the 68 pin socket is for?
Another search turns up this discussion at AtariAge
http://atariage.com/forums/topic/222274-intv-3-board/Guy has a non-working I3 where he pulled the the STIC and RAM from sockets in proximity to my socket. The board is marked ??TV 1987 opposite of where is marked. I notice for the first time that every picture I looked at had "organic" traces that look like they were drawn by hand. Mine, however, has straight traces, more typical of modern PCBs.
I finally notice that the RF modulator is
exactly the same as my board, right down to the stickers.
The evidence grows stronger.
Unfortunately, it's late and this research will have to wait.
Enjoy.....
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Topic: Mystery PCB (solved) (Read 6131 times)
