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So Chart45 isn't crazy... ADAM plays SGM games sans SGM!

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A while back, chart45 posted about a Stand-Alone ADAM Memory console he owned that could play all SGM required games (Thexder, King's Valley, etc... not talking about the ADAM Super Game conversions or other games that are enhanced by the presence of the SGM) without a SGM plugged into the side Expansion Port. Suffice it to say that a lot of us were skeptical until he posted pics and then a video.

 

So yesterday I received a Memory Console that I won on eBay (it's minty) and in my testing, I have found that this Memory Console will play all the SGM required games (sans sound as the SGM sound chip is used) as well. They include:

 

- King's Valley

- Thexder

- Rollerball

- Goonies

- Galaga

- TwinBee

 

Using Nanochess' SGM Test Utility rom image with NO SGM plugged in, I get the following results which I don't even remember now if they are the same with a SGM plugged into the ADAM:

 

DETECTED: Coleco ADAM

Base 24K RAM Ok

Lower 8K RAM Ok

Failure in the Sound Chip ...... (because the SGM is not plugged in)

 

I'll be taking the system apart to compare with my other ADAM system that can only play the games listed above if and only if the SGM is attached. I doubt there will be anything physically different between the two that will be obvious, but it's a start.

 

So if you have been waiting for an SGM for a while, you can always try picking up an ADAM and ask the seller if it will play all SGM required games. Be prepared to get some weird response though! :P

Edited by NIAD
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Well that is awesome! Now we can just forget about Opcode's SGM since he is MIA. I'll definitely be picking up Galaga now and getting the Adam!

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Yeah but as Jim pointed out there's no sound and it's not with every ADAM. I too posted this a little while ago that my ADAM can play SGM games without the module while another ADAM I have can not. I took both apart and still haven't seen what's different.

I'd like to add that the ADAM which allows me to play SGM games will not play them when I attach my 256k memory and addressor cards.

Edited by rey_1178

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Makes sense though that the Adam should be able to play SGM coded games since it can support Super Games datapacks. As for the sound, maybe someone can figure out a mod for the sound chip and which model numbers will play them and why so we have a functional alternative to the SGM since Opcode is apparently no longer making them. Good luck guys! Looking forward to the updates on this as it sounds very promising!

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That's weird about the 256K Memory Expander issue. I just have a 64K ME in my system currently so maybe it's something with the Parallel Card/Addressor that the 256K ME is attached to with a jumper wire.

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now we are a least 3 to have a super adam memory console

:grin:

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That's weird about the 256K Memory Expander issue. I just have a 64K ME in my system currently so maybe it's something with the Parallel Card/Addressor that the 256K ME is attached to with a jumper wire.

Could be Jim. I'll remove the other 2 cards and leave the memory expander solo to see if it works.If it doesn't then I'd have to guess that there's something different with the ram chips on some ADAMs.

 

It's hard to wait and see if Eduardo will resurface but it's good to know that someone else will be able to put together a similar module. It would stink losing that money though.

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now we are a least 3 to have a super adam memory console

Yeah, but the difference in our three Memory Consoles could actually cause issues with other carts or software. You just never know until you run across an issue, but at least we can check with one another if something comes up. Edited by NIAD

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possibility:

 

faulty ram may be why some of the games don't play on some the systems.

without some kind of diagnostics to test adam memory you'll probably never know either.

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Only theory is that the z80 can only address 64KB of memory at a time. Cartridge ROM is at $8000-$FFFF RAM would reside $0000-$7FFF. I think 256KB expander would has to be bankswitch or have a micro controller chip in order to read all of the memory. That might be the cause of the game not booting up on an ADAM.

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I take it that Expansion Module #3 wouldn't play SGM because it is using the CV to run game carts and not actually processing it through the memory module?

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I take it that Expansion Module #3 wouldn't play SGM because it is using the CV to run game carts and not actually processing it through the memory module?

That's how the Stand-Alone Memory Console works as well as there are two large PCBs inside it (the ADAM Logic Board and the CV Delta Board) and the CV Delta Board is pretty much the same PCB that is in a ColecoVision... the layout has just been altered and a large card-edge connector added to join it to the ADAM Logic Board.

 

There are, or should I say were because they were patched, a couple ColecoVision games (Defender and Super Cobra) that wouldn't work on the Stand-Alone Memory Console... so there are some differences between the two setups.

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possibility:

 

faulty ram may be why some of the games don't play on some the systems.

without some kind of diagnostics to test adam memory you'll probably never know either.

I have numerous Coleco made test carts which do check the built-in system RAM, but there is no way they do a byte-for-byte test as far as I can tell because the test only takes about 10 seconds. On all four of my systems (1 EM#3 and 3 Stand-Alone of which 1 can play all SGM games without an SGM), these Coleco test utilitites report the same results and if there was indeed faulty RAM in any of them, issues would be noticed while using other software or carts.

 

So I think it's something other than the actual RAM chips, but maybe the Logic Chips for the RAM. Anyway, I doubt the true reason why some ADAMs can play SGM games without the SGM while other ADAMs can't will ever be discovered. Well, of course, unless Opcode chimes in.

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I had to unplug the memory expander so a game requiring a SGM would work again.

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So now we know that a 64K Memory Expander can be installed and SGM games will still work without SGM attached but no sound. The same should hold true with a 128K M.E., but no one has these anymore and I highly doubt that the one made by Coleco will ever pop-up .

 

BTW rey, did you just disconnect the jumper wire between the 256K M.E. and Parallel Interface (system would then see it as a 64K M.E.) or did you have to remove the 256K M.E. completely from the system?

 

I got my 256K M.E. boxed up, so I can't test this for myself... sound familiar. :lolblue: Just kidding chart45.

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I first disconnected the jumper wire and when that didn't work, I removed the other two cards first, until I had to remove the 256k card.

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If the sound issue could be fixed, I believe this would also let the Atari expansion be used on the Adam using the native a/v? As is, it has no audio.

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If the sound issue could be fixed, I believe this would also let the Atari expansion be used on the Adam using the native a/v? As is, it has no audio.

 

Sound does work on the Atari Expansion with an ADAM...

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To try and help find a barometer, can you guys post the serial numbers of the working and non-working CPUs? I think I read there was also a manufacture date visible inside the cartridge port on the motherboard that could be useful. That might at least start narrowing down which production runs are compatible without SGMs. :)

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The games I have converted which need SGM will not work, since It checks both for if RAM is present and if the AY-PSG is present. Some of my games only need the RAM so they will work but it its a SGM only it will not work.

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The games I have converted which need SGM will not work, since It checks both for if RAM is present and if the AY-PSG is present. Some of my games only need the RAM so they will work but it its a SGM only it will not work.

which game you convert cause when i did the test with kings valley its show psg ok even if its not there if my memory is good....

 

let me know i will test it tonight and report

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If the sound issue could be fixed, I believe this would also let the Atari expansion be used on the Adam using the native a/v? As is, it has no audio.

As Geoff stated, the sound output does indeed work when the EM#1 is used with the Stand-Alone Adam Memory Console, but the volume output is VERY low and you have to crank the volume on your TV.

 

The same thing happens with the Opcode SGM on a Stand-Alone Adam Memory Console.

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I didn't realize sound worked. So, if you turn up the volume, it will work - is it loud enough to be playable? I need to check this out then, how about on a 1702 monitor?

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