Upgrade a Quadra 650 to a Power Mac 7100? The 7100 as a Home Computer

1999 – Two readers approach the Power Mac 7100 from different perspectives – one as an upgrade to a Quadra 650, the other as a low-cost home computer.

Should I Upgrade My Quadra 650 to a Power Mac 7100?

Power Macintosh 7100MSM writes: Low End Mac is a wonderful example of the use of the Internet to gain information about every aspect of Mac computing and my favorite bookmark!

I have a variety of Macs that are used by my kids and myself. My eldest daughter gets the IIci with the color monitor, #2 gets the IIci with the full page gray scale, and #3 gets the SE/30! (So do Mom and Dad, but they simply refuse to become computer literate so far, even with MacCribbage on the desktop). The first question I put to my daughter’s boyfriends is, “Which OS do you use?” a simple test every father can employ to determine whether these rascals are worthy suitors.

I run a Power Computing Power 100 (neat machine) with an Apple 21″ monochrome and E-Machines T16 and just picked up a NuBus Radius Thunder IV 1600 video card, which excited me more than is healthy for a grown man!!

Now the question: I have recently acquired a Quadra 650 and want to prepare it for the tribe, but I can see that jumping to PPC would be helpful for system and application upgrades downstream. I have noticed Power Mac 7100 motherboards coming onstream in parts sections of the various used Mac advertisers and wonder, given that I can find a great deal, whether the boards can be readily swapped with the Q650 and without other modifications that might make this upgrade of dubious merit. The access to used true PPC Macs here is rather limited, and they tend to remain overpriced relative to the cost of the iMac, for example.

Mac Daniel writes: First, thanks for the kind words. Low End Mac was just named Hardware Resource Site of the Year by The Clearer Picture, which absolutely thrills me. The site started less than two years ago when I couldn’t find a comprehensive resource on older Mac anywhere on the Internet – so I rolled my own, thanks to Claris Home Page and 5 MB of space that came with my personal email/internet account.

But enough history. You want to know the viability of upgrading a Quadra 650 and turning it into a Power Mac 7100.

My people have a reputation for stretching a dollar, so we try to look at the bottom line. The latest Macworld had 7100 motherboards for roughly US$300-400. The same dealers often sell a whole 7100 for $400-500.

For the extra $100, you end up with a second computer. Since a Quadra 650 sells for $150-200 these days, you could end up $50-100 ahead by buying a used 7100, swapping parts as necessary (maybe your Quadra had a larger hard drive – if so, put it in the 7100), and selling the 650.

Or hold on to the 650 and unload a IIci, which could probably fetch $75-100. That pretty much covers the difference in price, and you end up with two faster computers instead of one.

I’m Thinking About a Power Mac 7100 for Home

CR writes: I would like to get a low-level Mac for home. At the moment, I think a 7100/80 will do everything I need. For now I am not overly concerned with the speed. It will not be in constant use, often just word processing. If in the future I would want to upgrade, is this an inexpensive option? Any widespread shortcomings to the 7100/80?

Mac Daniel writes: The greatest drawbacks for the 7100 and other first generation Power Macs, the 6100 and 8100, are:

  1. They are not designed for processor upgrades, although some are available.
  2. They have slow motherboards – 40 MHz in the case of the 7100/80. This limits possible G3 upgrades to 320 MHz (the G3 can run at up to 8x motherboard speed).
  3. They use NuBus expansion cards, not PCI, so adding cards may be more difficult in the future.
  4. They use system memory for video, not special video memory, unless you get one with a video card or add one. This makes them much slower, although adding a 1 MB Level 2 cache can help that a lot.

The only reason to consider the 7100 would be cost – in light of their limitations, they should be at least $150 less expensive than the Power Mac 7500/100.

If you do want a 7100, I strongly suggest you look for a 7100/80av (with the AV card, it doesn’t use system memory for video, so it runs faster). If you can’t find a nice used AV model, be sure to add a 1 MB Level 2 cache for best performance (about $100, which greatly reduces the savings compared with the faster, more expandable 7500).

Reader Feedback

JMH writes: There’s a small technical inaccuracy in your article. All Power Mac 7100s and 8100s came factory-equipped with two video interfaces. The motherboard interface uses system memory and has the weird D-shaped AV video connector. Plugged into the processor-direct slot is an HPV (High-Performance Video) card or the HPV AV card. These cards carry their own VRAM video memory, with slots for additional VRAM. The video-card type is the only difference between the A/V and non-AV versions of the machine.

7100 product literature warned against booting the machine without a video card in the processor-direct slot, saying that machine damage could result.

With the two video interfaces, I run my 7100 with two monitors for the cost of an AV-connector to Mac-15-pin-video cable adapter. The motherboard adapter supports more color depths (down to black-and-white), but it is slower.

My sister’s 6100 only offers video on the motherboard connector and came with an adapter cable to 15-pin Mac video in the box.

G3 processor upgrades for the 7100 use this same slot, and most include an adapter for the HPV cards as an extra-cost option (though using such an option blocks a NuBus slot).

Mac Daniel writes: Thanks for the correction.

Keywords: #powermac7100

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