128k to 512k upgrade, need help!

[unity]

I was wondering if anyone has seen this upgrade before. I assume so, its a rather professionally done board. And the soldering on the motherboard looks factory, best looking upgrade I have ever seen done to a 128k board!

But the problem is the cable! This one has a cable that connects to the mobo and to the board. Problem is the plug has less pins than the connectors for both. And its not keyed! So I can shift the connector far left or right. I don't want to assume that they way its hooked up is correct. And looking at the upgrade board, it can go either way. Far left and right pins have traces that seem to go somewhere. Then there is another cable that is rather long. It has a three pin connector with 2 in use. It seems to have some damage that I will have to fix. The length is odd, makes me think it was for a switch or a light or something. I see no other connectors on the board to where this would go.

Since the board plugs in on a sockets as well as the RAM, this upgrade looks very reversible. But what is up with the LED and resistor at R11? These to are so well soldered in that is looks practically factory done.

 

[unity]

The mystery cable.

 

[Macdrone]

Have not seen that kind of upgrade yet. Mine are simple (look factory also). I'm sure the good solder back then always looked good.

Ill look at mine but ram is replaced of course, to be 512, and my board have a small board right above the place your cable plugs in. It looks more like a stand off.

Your upgrade makes me think more was done to my board if it has a chip that plugs into the board also.

 

[unity]

Have not seen that kind of upgrade yet. Mine are simple (look factory also). I'm sure the good solder back then always looked good.

Not the two I have seem! Solder rosin all over, etc. Not bad, just not clean! But I am sure there were degrees of craftsmanship! I know this particulat upgrade is not factory or anything. I was just surprised by how clean it all looks. Nice for a change!

Ill look at mine but ram is replaced of course, to be 512, and my board have a small board right above the place your cable plugs in. It looks more like a stand off.

That is what I have seen in the past. This plug is a new one to me and all my searches have not shown it to be typical. Which is why I concerned about doing a plug an play. I don't want to toast an original mobo!

 

[Macdrone]

Is their no marking on the case that mentions who made the upgrade? (Hoping)

 

[unity]

Is their no marking on the case that mentions who made the upgrade? (Hoping)

This motherboard came all by itself in a box. The bag is the standard heavily padded anti-static Apple carrier with no markings that Apple used very early on. The box is not an Apple service box, but smaller and a perfect fit. The only marking on the box is a "pin punch" of "942-0768-A (the 8 may be a 3)" on the inside, center. No paperwork.

 

[unity]

Just for reference sake, this is the exact packaging mine came in. Less paperwork, etc. I can only assume that my board was pulled and put in an empty package like this. One once used for an upgrade.

http://www.ebay.com/itm/331099970736?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

[Macdrone]

After I get sleep after work I'll see if I can look at mine and give you some help.

If McD sees this hopefully he will take an awesome close up of my 128 board so you can see what is and is not supposed to be there.

 

[unity]

Well the board boots as a 128k, thanks to this thread:

viewtopic.php?t=2882

I think system 4 is needed to check RAM size, I don't recall. But I don't have anything handy to see how much RAM is being addressed. I assume 128k. Since this board has an upgrade that uses a connector it was easy to put a plastic jumper on the connector for the two points where the trace is cut during upgrade. No need to solder bridge!

So I know the board is good! Nice to add a somewhat stock 128k board to the pile. But I would like to get the upgrade working. I could just plug it all in and cross my fingers...

By the way, the red LED is sorta neat. It just comes on with power. Not sure of the purpose, seems like a waste especially since the first few tries to get the board to work failed. So its not like it indicates a "good" board or anything. I noticed the 128/512 hybrid board does not have a location for it. But on the Plus board, its back again.

So Macdrone, any info you have would be great. But really trying to find an upgrade just like this one so I know more about the cabling. I'm done tinkering for tonight.

 

[bibilit]

Not sure a 100 %, but the Led was present in the Twiggy Mac.

 

[Macdrone]

3.2 about the finder will show memory size in bottom left.

 

[unity]

3.2 about the finder will show memory size in bottom left.

Thanks! I will create a floppy today and see what it says.

 

[unity]

Yup, 128k of RAM is seen along with upgraded ROMs. "128k."

For the heck of it, I tried it also without the jumper installed. It booted fine and again 128k. So what is the point of cutting the trace? Is it unrelated to the upgrade to 512k?

I still have not tried a random hookup of the upgrade board yet.

 

[Macdrone]

On the plus cutting that one resistor (not sure off hand which one) allows 4 Meg's of ram to be seen and used. That may be the case with the 512 upgrade. The only difference is the ram chips being larger in capacity and that jumper area to my knowledge, that's why yours is interesting.

 

[unity]

On the plus cutting that one resistor (not sure off hand which one) allows 4 Meg's of ram to be seen and used. That may be the case with the 512 upgrade. The only difference is the ram chips being larger in capacity and that jumper area to my knowledge, that's why yours is interesting.

I don't follow. The Plus has either resistors (early) or 3 prong jumper array (later). But in the case of this 128k board (630-0101) its certainly stock less the LED, resistor at R11 and the connector where normal 512k upgrades have a board or such soldered. With this board, that upgrade plugs in instead with a cable. Thats a little weird, but the real oddity is another cable with a plug on the end that seems to go nowhere.

As for the hybrid board produced for the 512k, with the option of also being a 128k board, there are some pretty noticeable differences compared to the original 128k board.

What I am thinking is maybe this board can be enabled or disabled with a switch? It certainly seems like a possibility as I see no other reason for the strange cable.

 

[Macdrone]

Now I have seen a 512 with a switch so that sounds ideal. But just weird you would ever want the option for less memory. At least your board works at 128.

Yes you are right the 128/512 board do have some differences. I was just mentioning that the plus as it was easy to upgrade that way, it was with the stand off piece the upgrade for the 128 boards by third parties were pretty easy for them.

 

[Quadraman]

You're a lot braver than I am. I wouldn't have given that board power at all without knowing for damn certain that the whole thing wasn't going to blow up in my face. It's obvious now that the upgrade either isn't working or isn't wired up correctly. I wouldn't risk powering it up again until you figure out what's what. Those original 128k motherboards are too hard to replace if it should be damaged by experimentation with an 'iffy' memory upgrade.

If you're really after a 512k upgrade to make your 128k machine useful (and a 128k Mac is basically a big doorstop without one), then $100 gets you an official Apple 512k motherboard practically any day of the week on ebay that is a simple swap with no soldering or rewiring necessary and you can always go back to the original 128k motherboard (minus the memory upgrade) at any time if you want to sell or restore it to original condition.

 

[unity]

You're a lot braver than I am. I wouldn't have given that board power at all without knowing for damn certain that the whole thing wasn't going to blow up in my face. It's obvious now that the upgrade either isn't working or isn't wired up correctly. I wouldn't risk powering it up again until you figure out what's what. Those original 128k motherboards are too hard to replace if it should be damaged by experimentation with an 'iffy' memory upgrade.
If you're really after a 512k upgrade to make your 128k machine useful (and a 128k Mac is basically a big doorstop without one), then $100 gets you an official Apple 512k motherboard practically any day of the week on ebay that is a simple swap with no soldering or rewiring necessary and you can always go back to the original 128k motherboard (minus the memory upgrade) at any time if you want to sell or restore it to original condition.

I guess it pays to know what one is doing then, and I do. Plus I have several spare boards, really don't care if a couple blow-up, even thought thats impossible.

 

[Quadraman]

You're a lot braver than I am. I wouldn't have given that board power at all without knowing for damn certain that the whole thing wasn't going to blow up in my face. It's obvious now that the upgrade either isn't working or isn't wired up correctly. I wouldn't risk powering it up again until you figure out what's what. Those original 128k motherboards are too hard to replace if it should be damaged by experimentation with an 'iffy' memory upgrade.
If you're really after a 512k upgrade to make your 128k machine useful (and a 128k Mac is basically a big doorstop without one), then $100 gets you an official Apple 512k motherboard practically any day of the week on ebay that is a simple swap with no soldering or rewiring necessary and you can always go back to the original 128k motherboard (minus the memory upgrade) at any time if you want to sell or restore it to original condition.

I guess it pays to know what one is doing then, and I do. Plus I have several spare boards, really don't care if a couple blow-up, even thought thats impossible.

You know damn well what I mean by "blow up", but in case you really are that dense, I mean burn up other parts on the board that would render it fully or partially non-functional and whether you have more or not is irrelevant. It would be irresponsible to knowingly damage such a rare part knowing how many people are looking for one and how rare they are. It would be like buying the Mona Lisa then painting a mustache on it just because it's yours and you can. You ruin it for everyone else who appreciates it the way it is.