Prototype 128k board?

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moosemanmoo's picture
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Joined: Aug 17 2004
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Looking around on ebay tonight, I found this little gem.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=80075&item=5202746824&rd=1&ssPageName=WDVW
The seller says that it appears to be a prototype board. I've never seen a production 128k mac motherboard, but the RAM being lined up and in a nice little box over there seems very zen and Jobsian. What's the verdict on this one?

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coius's picture
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Joined: Aug 25 2004
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Hey!

my board on my Macintosh (not 128/512k, just macintsoh) looks exactly like that! But mine isn't a proto... It still has the socketed chips

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dankephoto's picture
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Probably just another 512K upgraded 128K

Looks like it's just another upgraded 128K, common enough though the SN is an early one.

The socketed chips and that little extra PCB are the give-away. I've got a couple of these, each a little different from each other. Details kinda depended on who did the upgrade, there were lots of folks doing it back in the day. Seems like original unmolested 128K LBs are the rarer variety anymore.

Hey coius, how much ram does yours have? Bet it has 512K! Tongue

dan k

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coius's picture
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nope 128k

i got a hold of a floppy. I pulled it up and it had 128k ram. I am looking for a permanant floppy system. Abe should be getting me one soon...
I borrowed it from a MUG member who had one. He also let me fire it up with his K/M and we were set. So now all i need is Keyboard and mouse

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Joined: Mar 12 2005
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Protype My Apple!

These eBay guys make me crazy, always putting up stuff and hyping it as "RARE" or a "PROTOYPE" -- have you seen what the bid is up to -- over $80 for a 128k logicboard (and the reserve still hasn't been met)! A modified one at that! I wrote this guy to give me the info off the back which will positively identify the production lot of this board as a prototype or not. I wrote him twice -- he has not responded. This guy is a peice of work! It is very clear to me that this 128k board has had the 512k mod, the "unknown" board next to the CPU being a miniMUX to address the additional RAM, the chips socketed to allow for further expansion and a gold 68000 CPU (all like mine so far). The only odd thing about it is that the CPU is socketed. Easy enough to do, I just can't figure out why anyone would do it? Were there better 68000 chips one could acquire over the original 128k? Even if you could, wouldn't you have to clock chip it as well? The only other difference is that my serial number starts with CP, not LB. Why would a prototype have a production-type serial number anyway? I wish ebay had a way to allow other users to post comments warning others of potential pitfalls ...

coius's picture
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how about something along the lines of this:
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Joined: Mar 12 2005
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Socketed 68000

Ask and you shall recieve. It turns out a common upgrade stratagy for the 128k was a 512k upgrade and a CPU upgrade to a Motorola 68010 chip which was 50%-80% faster than a stock 68000! According to what I read, only the chip need be swapped to work and would easily explain the socket. If the guy had ever written me back, I would know whether the socketed CPU is in fact a 68010. In which case, the board is even more valuable than a so-called "prototype" (IMHO). What an Maroon.

Also, another common upgrade was the Brainstorm 68LC000 16Mhz CPU upgrade which also involved and upgraded system clock. Basically it would account for the socketed CPU and now that I look at it the different looking clock chip from the stock 128k. Again another rarity. However, my understanding was that this upgrade required special software (though I don't know why) in order to boot up -- seems like it would just start right up and just run faster -- Perhaps it needed a ROM patch to unserstand the accelerated bus. So the board is useless unless the buyer can come up with the software.

FYI -- I have a later 128k motherboard which has a serial number that starts with "LB", so this guy doesn't have a prototype -- just an early 128k board that's been upgraded.