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Power Macintosh era Questions!

ethump

Experienced Member
Joined
Jan 30, 2022
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61
Location
Sheffield, UK
Hi all,

I picked up a Power Mac 7100/80 recently. Just the main unit - no keyboard, mouse or screen.

Inside, there is a couple of sticks of DRAM regular memory (no idea the capacity) and what I'm learning is the ROM on a stick, and cache on another. Also, a 700Mb SCSI disk.

I can probably get an ADB keyboard & mouse easily enough. What are my options regarding display?

I see there's a chonky HDI-45 connector on board, I also have an add-in card which has a 15

I'm not minded to seek a CRT, I'd rather get an adapter and use a VGA LCD panel. I have VGA panels, and one works happily with my Amiga, if that has any bearing on an answer. I know sync rates can be a thing with some machines, not sure about this era Mac.

Also, what are my options regarding ethernet? I see there's an "Apple AUI" connector but it's not like I've seen before (I stopped using Macintosh around IIfx period. My Mac had a NUBUS 10baseT card). Guessing I need a dongle type media converter or something? Any pointers?

cheers!
e
 

Unknown_K

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Sep 11, 2003
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Ohio/USA
There are HDI-45 adapters out there to mac video (I have only one which I rarely use) but most people go with the PDS video cards and apple to VGA adapter.

I believe built in video was Sync on Green. Anyway, Apple used the standard 30Khz output so any VGA able monitor will work (unlike Amiga and their 15Khz).

You need an Apple AUI unpowered dongle for 10Mb ethernet.
 

ethump

Experienced Member
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Jan 30, 2022
Messages
61
Location
Sheffield, UK
Thanks!

OK good news on regular VGA panel!

This is the card in the PDS slot although mine doesn't have any memory in the SIMM slots.

So can I run the primary display from that 15 pin connector with an adapter?

Is this a suitable VGA adapter? Seems like I might have a challenge getting one of those in the UK for a reasonable price.
 

Eudimorphodon

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May 9, 2011
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Upper Triassic
Is this a suitable VGA adapter? Seems like I might have a challenge getting one of those in the UK for a reasonable price.

Ouch. That seems painfully expensive. In the US at least Amazon is still selling off new (old stock) Macintosh monitor adapters for less than $20.

These things used to be so dirt common it kind of feels wrong that someone is churning out new build ones. It feels like there just has to be enough of these things kicking around junk drawers to last until the heat death of the universe already, people just can't be bothered to look for them.
I believe built in video was Sync on Green. Anyway, Apple used the standard 30Khz output so any VGA able monitor will work (unlike Amiga and their 15Khz).

This applies to the old early Mac II series video outputs. Ever since the second generation of the LC series so far as I'm aware all Mac video outputs supported separate (VGA-style) sync. For a Power Mac most of the time you'll want to set the switches of one of these adapters for one of the "Multisync" settings. (Here's a typical example of the confusing instructions included with one of these things.)[/quote]

A small matter to watch out for is some LCD VGA monitors don't like Apple's oddball resolution modes like 832x624 or 1152x870, and Apple also used oddball refresh rates for their versions of some other modes, like 640x480 running @67hz instead of VGA's standard 60hz. Ironically you might have better luck with a scruffy old 17" LCD that predates Displayport/HDMI than a new one, the last generations of monitors with VGA ports often disliked displaying anything but the specific VESA standard modes they output in their DCID feed.
 

ethump

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Joined
Jan 30, 2022
Messages
61
Location
Sheffield, UK
Yeah slim pickings in the UK it seems. I'd be happy to pay the $20 for that one but they won't ship to UK. Others that will are charging $30+ for shipping.. Might look down the home-brew route. I should be able to get the parts for that $20 and repurpose an old VGA cable.


Those DIP switches are configuring pins 10, 7 & 4 to tell the Mac which video mode to spit out? More learning required :)
 

Mr Fahrenheit

Experienced Member
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Dec 28, 2020
Messages
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Location
North America
I have always had the best experience using the NEC Multisync VGA adapters on Macintosh. They don’t require any dip switch settings, and support most/all of the resolutions you’d ever need or want to use.

When people on Reddit have had problems with no video output I point them in the direction of an NEC adapter and I’ve always had a reply back later saying that fixed the problem.

Like this one:

 

Timo W.

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Nov 25, 2014
Messages
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Germany
"Multisync" is something you can also set on those with dip switches. It's a Mac setting. The adapters with dip switches are more compatible, as not every Mac knows about Multisync and will not give a picture then.

But basically, they will all work on a 7100.
 

Eudimorphodon

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The gotcha of the switch-less adapters is not all of them *are* “unlocked” multisync. Unless you know for sure what you’re getting you might end up with an adapter hardwired for 640x480 *only*. Those were dirt common because they were used with LC-class Macs in schools and whatnot.
 

Chuck(G)

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I just made my own adapter using DA15 male and a DE9 male connectors. After that, it's just a matter of wiring things up for the desired resolution. Network adapters are a little trickier...
 
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