SE accelerator - what am I looking at?

JeffC

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Sep 26, 2021
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I'm looking at this old 16mhz 68000 accelerator for an SE, and I can't quite figure out what's going on with the PDS connector. I know this style of male PDS connector with just exposed pins and no plastic surround wasn't uncommon, @JDW said he has a board with a similar connector. What I can't figure out is why it appears the pins aren't soldered to the board. In the photo of the full back of the board, you can see many of the pins are bent, it looks like someone removed the card at an angle by pulling up on the far edge. I asked the seller about the bent pins, and they attempted to straighten them, which is why they look different in the close-up photos. I asked if the connector was loose, thinking maybe someone had removed the PDS connector at some point and just set it back in, and they said nothing is loose. I also can't tell if the pins are rusty, or if they just appear that way in the photo. No other part of the board looks corroded to me.

Does anyone have any thoughts about the seemingly un-soldered pins, or the condition of the connector?
 

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JDW

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Jeff, that's a Mobius brand SE accelerator, but maybe @BFEXTU might have some thoughts on it since it's quite similar to the SuperMac SpeedCard in design, especially with the pins coming out like that at the bottom of the card. Unlike the SpeedCard though, there is a passthru connector on top of the card you are showing, which is interesting.

I guess wave soldering could have soldered the pins at the top of the board under the connector, but I would think there should be at least some solder on the bottom as well. Hmmm.

Some pins are bent, but not to a level that couldn't be straightened, assuming the solder on the top of the board, under the connector hasn't cracked. That's really the main issue and great unknown.
 
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retr01

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Where is the CPU? If there is a 16 MHz 68000, where is it? And I can see it's specifically "Speedscreen SE" by Mobius Technologies in 1990. It supposedly helps with redraws on external monitors.

1670552155550.png


And I noticed that there is currently a listing on eBay for that card:

 
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JeffC

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The CPU is the square chip in the center, if you zoom in it says 68000.

That's the same one I'm looking at on eBay, I requested the additional photos from the seller.
 
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retr01

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The CPU is the square chip in the center, if you zoom in it says 68000.

Aha! No wonder I was confused, especially since the 68000 CPUs generally have the Motorola logo, whereas this 68000 has the "ST" logo, which seemed unknown to me. :)

That's the same one I'm looking at on eBay, I requested the additional photos from the seller.

Ah. Cool.

I have been trying to find more information on this or similar Mobius cards for the Mac SE. I know I probably would find an article about it in one of the magazines back in the day. It's out there somewhere.
 

Trash80toG4

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I guess wave soldering could have soldered the pins at the top of the board under the connector, but I would think there should be at least some solder on the bottom as well. Hmmm.
Solder side would be wave soldered with components in place topside. The DIN connector would then be installed afterward, soldered by whatever process on the component side of the board.

Closeup pics of a portion of the connector's thruhole pins topside would be good to see. Ought to be some variation on the regular cone shape?
 

BFEXTU

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I vaguely remember Mobius, but I don't think I know anything about the SpeedScreen SE. Sorry.
 

Trash80toG4

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Mobius made VidCards, that seems to be what this is with very simple 2x acceleration built in. 1990 is kinda late for producing something as rudimentary as this appears to be. I guess it could make a decent word processor level machine in that time frame likely with a cheap TTL monitor.

Programmable Logic next to the breakoput cable connector wasn't needed on an 030 accelerator like the Performer. Controller/digital equivalent of a RAMDAC?

 
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