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6100/66 DOS Compatible


Well-known member
Just saved this PowerMac from going to the dump. Turns out to be a 6100/66 DOS Compatible. I have never actual seen one of these before. I cleaned off the snow and dried it off. Lots of snow and ice here! I plugged it in, it chimed nicely, but no video output. It has a 500mb SCSI harddrive. The DOS card has a 486 DX2 cpu on it. The harddrive runs quietly. Not really sure what I will do with this unit, but I will try and get it going.



Daring Pioneer of the Future
Staff member
Congrats on the 6100! Do you have the crazy video cable to use the DOS part?

For the no video problem, it might be a flat PRAM battery -- you might try doing the quick switch on/off/on thing, or (maybe more safely) subbing in a known-working pram battery.



Well-known member
You need the DOS card cable along with the weird Apple high density video connector to normal apple video connector for that setup to work. Exactly where did you try to plug a monitor into it?



Well-known member
I have the cable that goes to the odd video port on the 6100 then to a regular early Mac monitor plug in. But I was using another adapter on the cable to use a LCD monitor. I will dig out a Mac crt monitor and try again. I will get another pram battery too. There is a plug in on the DOS card that has three rows of pins on it. I have nothing to fit that one. I will unplug the DOS card and see if the video will work that way. All the slots on the motherboard are full. I want to get it going, so I can see what the specs. are. Hopefully get back to it tonight or tomorrow morning.



Host of RetroChallenge
I had one of those... I remember the first time it spontaneously booted into Windows 3.1 I just about crapped.



Well-known member
There is a plug in on the DOS card that has three rows of pins on it. I have nothing to fit that one. I will unplug the DOS card and see if the video will work that way.
That sounds like the audio pass through for a CD-ROM drive. The DOS card emulates a SoundBlaster but requires an analogue signal from the CD drive. When I last looked, Apple still had the user manual for the 6100 DOS card, which includes installation instructions.


Hotdog Zanzibar

Well-known member
Nice find! I have one of these in my storage room. The DOS card allowed our secretary to log in to some accounting software used by Nationwide Insurance at the time, using a modem. I was the one who set it up, but I never did get used to seeing Windows 3.1 load on a Mac. :) The DOS card will accept up to 32mb of RAM in its single slot. And even though Apple never officially supported it, you can throw a couple 128mb SIMMs in the 6100 and get 264mb of RAM -- WAY beyond what Apple's specs will tell you. Add a decent video card and you'd be amazed how much more powerful the computer is!



Well-known member
I was able to get the video working on the 6100. Just did the quick on and off of the power switch. It booted up fine. It is running O.S. 7.5.5 with a total of 16mb of ram. There is also a 16mb strip of ram on the DOS card. The floppy drive works fine. This one does not have a cd drive. But I may add one as the cable is there . I will do some reading so I know how to get the Windows partion on the harddrive to show. The unit cleaned up well, just a little yellowing on one corner of the case. An interesting vintage PowerMac.