Megatouch xl SRAM?

[truckerbob]

Hey, guys. I'm new to the forum, and picked up my first game yesterday. I got a decent deal, the monitor works, after changing out a CD drive, the bios picked it up, but I still got the system disk error.
After opening the case,  I'm believing the P/O May have dropped it. I checked the I/O board, and the riser wasn't even plugged into the motherboard. After checking all the chip sockets, the SRAM chip looked to be unseated. Looking closer, the chip was only half seated, and about half the pins were bent. I tried straightening them out, but ultimately broke 2 pins.
So, I found a supplier in Hong Kong, and ordered a new Dallas DS12304Y-150 chip. My question is, would I have any old electronics with that chip in it? Secondly, is there a proper orientation for installing the chip into the socket? I pulled the spec sheet, and I'm somewhat familiar with the pin layout, but the chip I removed had no markings to identify pin 1.
Thanks in advance!

[orizzle]

this doesn't really answer your question, but I do have an extra ioboard and keys if you want to replace yours

simply replacing the Dallas chip is probably not going to work. it'll need programmed

[truckerbob]

Ok, thats where i was getting confused.  I didnt realize SRAM needed programmed, when i read "Dallas Chip", I assumed it was the white chip, that was matched to the EPROM.
Shoot me a message, and let me know what you'd like for your ioboard. I'd really like to see this thing run.

[orizzle]

You probably only need a key. I have a platinum key but don't have the actual software. ebay has some xl keys also

[truckerbob]

OK, I'm still new at this, so to make sure we are on the same page, I took some pictures.
This is the SRAM chip I was talking about, and the one I ordered.

It had a label with the model and serial number of the unit on it, until I removed it.


This is where it was located, on the I/O board, just to the right of the EPROM.


This is what I believed to be the "Dallas Chip", and any of the upgrade kits I see, have that chip and an EPROM with the CD.

Now, if that chip I ordered isn't going to do me any good, would I be better off just buying a complete upgrade? I found a titanium kit, it includes the motherboard, the I/O board, hard drive, and power supply, and touchscreen controller.
Thanks for your patience with me, I'd much rather figure out why it doesn't work, than just replace parts.

[orizzle]

Your key is what you have circled in the last picture.  I don't know what the chip is that broke off - my guess is the SRAM might be the small bootdisk that runs when you turn the machine on.  You might be able to get away with just a new hard drive and key.  But your machine probably will not boot without that chip if the boot data is on there.

[truckerbob]

Ok, thanks for your help, orizzle. I'm probably going to buy the titanium upgrade kit anyway, but I still have that chip from dallas being shipped.  Maybe Ill just keep my eyes open for another parts machine and have a friend who does programming for a living see if he can "clone" that broken chip somewhere down the line.

[orizzle]

just don't get ripped off.  a lot of those kits are expensive, and might be able to upgrade to a Maxx for around the same price

[truckerbob]

I dug into the service manual last night, and I'm even more confused now.

The schematic shows the broken chip as the Dallas key...


But, 2 pages later, it identifies the Dallas Key as being near DS-2 and DS-3 (the physical DIP switches), which would be what is identified as the "security key", in the schematic.



Does anyone have any insight to what the "R2/R3 CD" is?

Orizzle, I sent you a PM on the kit, let me know what you think. Thanks.

[ice2921]

You mentioned you replaced the CD-ROM drive on this. Do you know what model you need to replace it with?

[orizzle]

Does anyone have any insight to what the "R2/R3 CD" is?

Orizzle, I sent you a PM on the kit, let me know what you think. Thanks.

Never heard of this R2/R3 CD.

Re: your PM, keep the topic going here.  Your XL controller  should work just fine with Maxx.  You'll need a new motherboard, ioboard (I don't think XL will work with Maxx - someone correct me if I'm wrong), key, and hard  drive. You can use any hard drive and install the software yourself.

If you can wait, try to find a good price on these items.  Every so often a Maxx motherboard/ioboard combo will go for $25 on eBay.

[truckerbob]

You mentioned you replaced the CD-ROM drive on this. Do you know what model you need to replace it with?

I replaced it with what I had laying around.  I grabbed a couple drives out of my garage, and the first one "worked".  It was a Sony CRX140E.  It was recognized in BOIS, as well as the startup.

[truckerbob]

Does anyone have any insight to what the "R2/R3 CD" is?

Orizzle, I sent you a PM on the kit, let me know what you think. Thanks.

Never heard of this R2/R3 CD.

Re: your PM, keep the topic going here.  Your XL controller  should work just fine with Maxx.  You'll need a new motherboard, ioboard (I don't think XL will work with Maxx - someone correct me if I'm wrong), key, and hard  drive. You can use any hard drive and install the software yourself.

If you can wait, try to find a good price on these items.  Every so often a Maxx motherboard/ioboard combo will go for $25 on eBay.

I'll definitely keep this going here.  This is getting to the point of being fun, now.   Ill keep you guys updated, and now I need to try to research that R2/R3 CD.

[truckerbob]

Just an update, my hardware came in on Wednesday, and as of last night, I have a working Megatouch XL, running Titanium.  You'd think after years of tearing things apart, I would have learned to take pictures of wiring routing, and connections before I disassembled things, but I guess I enjoy the pain...

There was no jumper on the HDD when it arrived, so, it took some trial and error to get it working.  Just in case anyone else has issues in the future, here is what happened with all 5 jumper settings on my HDD.

CS (closest to the Molex) - Drive recognized in BIOS, the system would boot up as far as initializing the touch screen.  Then I would get a message in pink text stating "Hard drive copy error"
Slave - Recognized in BIOS, but gave me "Bad command or file name"
Master - Not recognized in BIOS, and gave me the insert system disc message
Blank - same results as Master
PM2 - WORKING MEGATOUCH!!!!!!!!!

Now, from what I'm reading about the PM2 setting, it looks like it may be indicative of a pending drive failure, but I guess time will tell.

So, back to my original issue.  I changed the jumper setting over on the I/O board, and swapped out the HDD for the CD-ROM, and tried to run the CD that came with my machine.  I'm still getting the boot disc error.  I was successful in making an ISO of the CD with IMGburn, so from what I read, that means my CD is ok.  Do you guys have any ideas?

[obcd]

An original megatouch xl with cdrom boots from a romdisk on the io adapter.
That romdisk can be disabled with a jumper on the io board.
Old computers boards like the megatouch ones can't boot directly from cdrom. It's not implemented in the bios.
The DS1230Y is a non volatile sram chip with buildin battery. It's used to keep the settings and the highscores. The protection key is made by Dallas as well. Some people thought you needed a new security key instead of a new non volatile sram chip...The eprom chip next to it is the bios extension for the flashdisk. The flash chip next to it is the disk itself containing the romdos.
So if you have a boot disk not found, it's related to the io board and has nothing to do with the cdrom.

[truckerbob]

OK, so if I understand correctly, both I/O Boards I own have bad romdisks then?

[obcd]

It doesn't has to be the romdisk that is faulty.
Most problems with the io board - motherboard interfacing will result in that famous "can't find bootdisk" problem.
Such problem can be a bad contact on the io board or the riser board. It can be an address line buffer or data line buffer, not only on the io board but also on the motherboard. It can even be increased ripple caused by aging capacitors in the power supply that disturbs the proper function of the io board.
Basically, you should test piece by piece in a working setup to figure out what is causing the issues.
If you change your setup to a harddisk one so that the romdisk isn't needed anymore, the problem might become a sound issue or it might say that the nvram is corrupt every time. Those are also parts on the io board that can malfunction. 

[truckerbob]

Ok, I understand what you are saying. I'm waiting on my SRAM chip, and once I get it in, I'll try changing out parts from the working setup I bought, and see what happens. Thanks for the advice.
On an unrelated note, I found a non working maxx on Craigslist I'm thinking about looking in to, any idea what the maximum I should think about offering is? He's stating it won't power up, I'm leaning toward a bad PS, or plug...I don't want this to be an addiction, but being a 40-something I spent plenty of money playing these games in bars, and it's something I've always wanted.