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Macintosh Plus Internal SCSI MOD


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  • 2 weeks later...

@360alaska Are you not at all powering the SCSI2SD board like shown on your photos?

 

Or is the little bit of power going into your adapter board enough to make it run on the current coming through the SCSI cable?

 

If you are feeding the SCSI2SD board its own power, where from are you drawing it?

Edited by Joris W
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43 minutes ago, Joris W said:

@360alaska Are you not at all powering the SCSI2SD board like shown on your photos?

 

Or is the little bit of power going into your adapter board enough to make it run on the current coming through the SCSI cable? 

 

If you are feeding the SCSI2SD board its own power, where from are you drawing it?

SCSI2SD V5.0, V5.1, and V6.0 are all capable of and designed to be powered by SCSI termination power alone, when the SCSI Host Bus Adapter provides it, which is almost, but not always, the case :)

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  • 3 months later...
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Posted (edited)
14 hours ago, 360alaska said:

Yep, it's a difficult install, but... it works... I don't think anyone else has designed a board the does this...

Does anyone know if a 40-Pin IC Test Clip will connect to the SCSI IC? (NCR/AMD 5380)?

edit: I can't find information on the NCR 5380 pin pitch, but the clip is 2.54mm

image.png.6a5a6f41ed5440777d738518fb9445b6.png

Edited by Stephen
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Yeah I broke a Killy clip a while back.  Still kicking myself.  I have no idea how to find one other than getting your hands on an accelerator that includes it.

 

I printed up one of @360alaska’s SCSI add-on boards a couple years ago (nice design!!) and it’s terrific though I’m averse to making irreversible-ish mods to my Plus motherboard.  I would absolutely love a clip-on version.  I guess if someone could design up and 3D-fab a Killy-style clip for the NCR SCSI chip DIP package, that would be pretty amazing?  :)  

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Posted (edited)
8 hours ago, Crutch said:

Yeah I broke a Killy clip a while back.  Still kicking myself.  I have no idea how to find one other than getting your hands on an accelerator that includes it.

 

I printed up one of @360alaska’s SCSI add-on boards a couple years ago (nice design!!) and it’s terrific though I’m averse to making irreversible-ish mods to my Plus motherboard.  I would absolutely love a clip-on version.  I guess if someone could design up and 3D-fab a Killy-style clip for the NCR SCSI chip DIP package, that would be pretty amazing?  :)  

I’m capable of 3D designing the housing but I don’t think we have a good / reliable option for the pins / contacts?

 

if anyone has thoughts then please feel free to share; I would love to come up with a solution for this neat mod which which doesn’t require modifications to the board.

 

edit: maybe a PCB with pogo pins / spring probes combined with a 3D printed chassis to clip it to the edges of the chip? I’ll take a look this evening and see if we have options (sufficiently short pogo pins).

Edited by Stephen
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Posted (edited)

Separate pieces of the same thoughts:

 

A possible candidate for the connector (over $20 for the connectors)

image.png.003183106841cfedfa3747dafbce2bc7.png

 

There there's this killy-clip-clone (cloney-clip?) that I came up with. I haven't tested it but it uses the same clipping strategy to pressure fit over the far sides of the chip as the original killy-clip (the access hole is to "unclip" it). I can confidently 3D print this on my resin printer but I don't think it would be possible on an extrusion printer. The tolerances are in the 10nm (0.10mm) range.

 

 [optimize output image]

 

So... together it would be a PCB housed on the 3D printed "cloney-clip" chassis. The chassis would fit over the ends to hold the PCB in place and the PCB would push pins down onto the legs of the AMD/NCR 5308.

 

Not gonna bother unless more than one person (me) is interested. 

Edited by Stephen
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