This page was archived in 2023 as part of the Mac Hut archive and is no longer updated.Most of the site pages were last updated around 2008 and some information may be out of date. Become a patron: Support our efforts by contributing a small amount each month to cover our hosting costs and the time it takes to archive these pages properly. Thank you. |
Came here from the web? Check out the Homepage!
The Power Macintosh 7100 motherboard is exactly the same size and shape as the motherboard of the Macintosh IIcx, IIci, and Quadra 700. The square case of these three previous models is preferred by many to the PowerMac 7100 case. Installation of this motherboard into this case is easy, and requires only slight modifications to the case itself.
Please don't perform this modification to a Mac IIci or a Quadra 700--Each of those machines is a classic, and the height of it's day. They're amazing machines in their own rights and possess qualities that a 7100 conversion could never have.
On the other hand, please do this to Mac IIcx machines. To be blessed with such a great case and cursed with such a terrible motherboard deserves a reward: to get a new 7100 motherboard! I built the machine you see here from a wayward IIcx with a broken motherboard.
Here's an overview of the modifications that will be required: the Barbaric Square Hole, the In-Security mod, Lopping Off the Supports, and What About the Speaker?
Upon first building this machine, I found that touching it even slightly caused a crash. This didn't happen when the parts were on the table naked and running, however. The motherboard was shorting out somewhere due to the conductive paint Apple sprayed inside the case.
My first solution was to cover the back of the motherboard with duct tape. This worked well, but I later came to regret it. After nearly an entire can of circuit cleaner, I removed the sticky mess. I used spraypaint in a fairly thick layer inside the case, and the crashing (and tape) is gone!
The first problem a hacker will run into is the fact that the PowerMac has a different port layout than the Macs that used to inhabit this case. An ideal solution would be to fill in the holes using some kind of putty and then redrill the case for the correct port locations. We're not going to do that. Here's the mod: Use trial and error to make the height of the slot large enough to fit the high-density stupid video connector through--it's the tallest.
The case includes a connector to attach a security chain to prevent computer theft. This "port" is right in the way of where the PDS connector is on the 7100 Motherboard. To fit a G3 upgrade card, the internal structure of the Security Port must be removed. To fit a PDS Video or A/V card, more radical surgery would be required--I recommend using the PDS for a G3 card and adding a NuBus video card such as a Radius Thunder-series board or the VillageTronic MacPicasso 340.
Here's the mod. The back side of the Square Hole is also visible.
The IIcx and IIci motherboards have three slots which accept hooks on the case floor and support the motherboard's center section from moving vertically. The PowerMac 7100 has only one such slot--The other two hooks have to move! When chopping them off, leave enough height that they can still support the board from below, if not above. This picture shows the three supports labeled and which ones I cut off:
Note that there are more holders inside the case than only the ones I have labeled: a hacker must use their own judgement and remove the necessary ones.
The IIcx and IIci have an internal speaker mounted in the front on a plastic device that also holds the motherboard in place. The IIcx and IIci speaker is not compatible with the 7100 motherboard, though. Because the impedance is different, use of the standard 7100 speaker is necessary. I removed the speaker and its support plastic and created a mounting bracket for a large case fan to supply extra cooling to the G3 upgrade I planned on placing in the PDS slot.
Because my system was designed from the start as a dedicated workstation for MacroMedia Deck II, an internal speaker wasn't necessary for this machine. Other hackers have attached the stock 7100 speaker to the inside of the case with industrial Velcro and met great success. Here's a side and top view of my modified "fan" mount:
After all the plastic dust settles and the Dremel cools off, here's what the completed workstation looks like. It is configured with a DigiDesign AudioMedia II for sound I/O, a Radius PrecisionColor Pro takes care of graphic duties, a FWB SCSI JackHammer chats with the disks, and a Sonnet 260Mhz G3 card does the processing.
Audio data is modified in the 136MB of RAM and saved on a Western Digital 10,000 RPM Fast-Wide drive. The floppy drive bay is occupied by an IBM UltraStar, from which the system boots MacOS 9.1 and Deck II 2.6.1. While it can't been seen in any of these pictures, this particular IIcx case has the signatures of the product design team etched into the base. I think they'd be proud.
Text and Images copyright 2003-2008 Tyler Sable
Information is presented for research and enterntainment only
.
Any actions taken are the sole responsibility of the reader.
NO WARRANTY is expressed or implied.
