ECS board variations

[rietveld]

I just opened both of my ECS's and they are slightly different on the edge connector

 

How many variations were there?

[BSRSteve]

Were the units both made in the same location?

[rietveld]

Not sure. One is in a brown case from Noryth Africa and the other is a white one from a guy in Texas

[rietveld]

https://imgur.com/gallery/P0DN4zy

 

Brown ECS with wires soldered to traces on the card edge connector

[nick3092]

Check the thread below. It starts out talking about the memory expansion, and then turned into people comparing their ECS innards.

 

http://atariage.com/forums/topic/288947-ecs-program-expander-was-planned-in-brown/page-1

[mr_me]

I was looking for the reference post but couldn't find it. I think Lathe26 discovered that the brown ecs has a different uart chip to account for the different master clock in the master component. That wire might be unrelated. What's the serial number on your white ecs.

Edited May 14, 2019 by mr_me

[+Lathe26]

The brown ECSs have a black wire connected to pin #4 of the connector. This pin is either CBLANK or C2, depending on whether the ECS is connected directly to the Intellivision or if there is an Intellivoice in between. The black wire runs to a couple bodge parts: a pull-up transistor and a pull-down resistor. This probably was to either clean up the voltage levels or allow more current draw on this signal. On other ECSs, this signal runs straight through the ECS. On brown ECSs, this "straight through" trace is cut so the signal doesn't bypass the bodge parts. You can see the trace is cut in your photo in the lower left near the yellow-green inductor labeled as L6 (printing is upside down so it looks like "97" at first glance).

 

I have no idea why this was added to only the brown ECSs.

 

On the other thread, you mentioned the black wire was soldered to 2 pins, just to 1 pin (pin #4). What are all the pins it is soldered to?

 

Regarding the UART chip, it is unrelated to this. mr_me is pretty close to correct. It's not so much that a different UART chip was installed but rather that the black glob chip has a pin that is grounded on brown ECSs that is left unconnected on white ECSs. This pin controls accounts for the different master clocks in NTSC vs PAL Intellivisions (i.e. the pin changes what to divide the MCLK signal by).

 

As for variants, there are 4 that I know of:

1. Early run white ECSs with Expansion connector
2. White ECSs with Expansion connector
3. White ECSs, no Expansion connector
4. Brown ECSs, no Expansion connector

There are differences between #1 and #2 that I still need to investigate.

[rietveld]

Upon closer inspection the wire is only connected to one pin. It looked like it was touching both but that is not the case

 

I bought my brown ECS from a guy in Tunisia Africa. I assume he would have used it with a PAL intv. It seems to work perfectly with my Tandyvision 1 that is NTSC. Does the ECS auto detect what region it is connected to?

[Intymike]

Upon closer inspection the wire is only connected to one pin. It looked like it was touching both but that is not the case

 

I bought my brown ECS from a guy in Tunisia Africa. I assume he would have used it with a PAL intv. It seems to work perfectly with my Tandyvision 1 that is NTSC. Does the ECS auto detect what region it is connected to?

 

 

I have grey and brown ECS and PAL and NTSC Intellivisions. I interchanged both a lot and never found any differences.

[mr_me]

Tunisia had secam but both pal and secam intellivisions had a 4khz clock. The ECS doesn't auto-detect that, which is why they built them differently. I think the differences would only effect cassette tape I/O, and maybe the serial port.

[rietveld]

Tunisia had secam but both pal and secam intellivisions had a 4khz clock. The ECS doesn't auto-detect that, which is why they built them differently. I think the differences would only effect cassette tape I/O, and maybe the serial port.

That actually explains a lot I thought my Aquarius printer was broken since it wouldn't work with the brown ECS.

I just connected it to my grey ecs and intv2 and it does print with that setup.

[+Lathe26]

mr_me is correct, only the cassette tape and serial port are affected by the Intellivision's clock speed. If you used a PAL or SECAM Intellivision, your brown ECS would work fine with the Aquarius printer.

 

Side note: hooking up an ECS and Intellivision that are mismatched (ex: brown ECS with NTSC Intellivision or white ECS with PAL/SECAM Intellivision) can write to a tape but only that same mismatched combo will be able to read the same tape back again since it was recorded at the wrong speed.

[+fdr4prez]

Side note: hooking up an ECS and Intellivision that are mismatched (ex: brown ECS with NTSC Intellivision or white ECS with PAL/SECAM Intellivision) can write to a tape but only that same mismatched combo will be able to read the same tape back again since it was recorded at the wrong speed.

 

So it is very much like a secret message coder/decoder system?

 

You write (tape) the secret message with one mismatched setup and send it out, but only those using the same "decoder" mismatched setup can read the message, yeah?

 

Now there can be an Inty International Spy Club