Greetings and welcome to a classic LGR computer thing!
And this time we’ve got a fascinating hybrid system from 1995:
the Power Macintosh 6100/66 DOS Compatible.
Yep, this is an Apple product built to run both Mac OS and Microsoft DOS, with the ability
to switch between the two at any time and even run programs simultaneously.
Check it out!
[keyboard keys clacking]
[Passport.mid music plays]
Ahh, this is precisely my kinda fun right here.
Sure, you can perform similar tasks running Windows software on a modern Mac using Parallels,
but that uses virtualization software and an existing Intel CPU to do the job.
This 6100, however, doubles up on hardware to achieve a high level of integration between
the warring factions of DOS and Mac OS.
So in addition to the Power Mac’s 66 megahertz PowerPC 601 CPU, there’s also a legit Intel
486 inside, working in tandem with the Macintosh half of things
to provide two computers in one.
As you may imagine, this was not cheap,
starting at $2,199 when it hit the market in January of 1995.
At least for one with a 2x CD-ROM drive, 500 megabyte hard disk, and 16 megs of RAM.
But memory upgrades were very much recommended, since by default,
system RAM was split between DOS and Mac.
So the total cost could rise to about $5,049 in 1995, if you wanted the officially-supported
maximum of 72 megabytes of RAM.
Yeah memory was expensive stuff back then, I mean look at these prices from October ‘95.
Over $1,400 for a single 32 meg memory module,
and you needed two of them to max out this machine.
Then there’s the DOS Compatible PDS board itself that can take its own 72-pin SIMM module,
so adding just 16 megs to that would’ve set you back another $700.
Still, even without any RAM upgrades at all, the 6100/66 DOS Compatible was appealing on
a multitude of levels for the right customer.
You’re effectively getting two complete systems in one here, and for folks that used
DOS at work and a Mac at home, or vice versa, then this was a mighty tempting setup.
Yeah it cost a good chunka change,
but it was still less than buying a 486 PC and a Power Macintosh individually.
And if you already happened to own a compatible Mac, Apple also sold the DOS Compatible PDS
card on its own for $739.
There were a whole slew of these cards from Apple in the mid-90s too, but this card here
comes with a 66MHz 486DX2 processor on-board, 256K of L2 cache, and a Chips & Technologies
graphics chipset accessing 512 kilobytes of video memory.
You also get a Creative Labs Sound Blaster Vibra 16 chipset, providing both 16-bit stereo
PCM sound and Adlib-compatible OPL3 music for MIDI playback and FM synth sound effects.
This passes through the CD-ROM audio header on the Macintosh mainboard, meaning that both
DOS and Mac go through the same audio system to play through the 6100’s internal speaker.
And around back is a multi-function port with a breakout cable providing both video output
and a 15-pin gameport, so PC joysticks and monitors both plug in here.
Speaking of monitors, there are two ways of displaying DOS.
One is to use a single monitor and combine the two outputs using that breakout cable,
making the DOS system pass through to the Mac.
Doing it this way, a keyboard shortcut is used to switch between DOS and Mac mode, so
only one or the other can be viewed even though they’re both running simultaneously regardless.
Or you can use two separate monitors, one for the DOS card and one for the Mac, by plugging
each display into their respective video output ports.
This lets you see both operating systems running at the same time side by side, though you
can still only use or the other seeing as peripherals are shared between systems.
Though, I suppose you could play a game with a joystick on the DOS side and play another
one with a mouse on the Macintosh side, but uh yeah,
not much point to that other than it being awesome.
Oh and in my case, I’m doubled up on dongles here, since the 6100 uses an HDI-45 port for
video and I don’t have a monitor that uses that.
But for now let’s ignore this array of Apple adapter aggravation, hide it all away behind
here like it doesn’t exist, and try out some classic DOS games
on our Apple-sanctioned 486!
[powers on]
[6100 startup chord plays]
[notable hard drive/fan noise]
Ah that short-lived Mac startup chord, haven’t heard that in a while.
Not that it was easy to hear at all with how loud the fans and hard drive are.
The latter of which is louder than it should be
but like my local city council that’s mostly due to its age.
Anyway yeah, this particular 6100/66 received some upgrades by its previous owner, with
the aforementioned 72 megs of RAM and also System 7.5.3
an incremental update over the factory-installed 7.5.
And while there are plenty of powerful Mac things to do on this Power Mac, the DOS Compatibility
mode is the star of this particular show.
The way this works is that you simply press Command+Return on the keyboard, and it’ll
switch right on over into DOS mode and begin booting the system just like a PC.
Mostly, sort of.
Eh okay, I’ve been beating around the bush this entire video so far, but you may have
noticed that I haven’t yet called this “PC compatible.”
Because it’s not. Not exactly.
Apple specifically calls it “DOS compatible” because it is specifically made to be compatible
with software for MS-DOS, not an entire Intel-based PC.
Due to its reliance on the Apple software used, which manages everything from peripheral
sharing to booting the system, it’s only designed to run MS-DOS version 6.0 and higher.
So that means no OS/2, no Linux, no x86 BeOS, no Windows NT.
Although, this does mean that it fully supports Windows 3.1
and even Windows 95, albeit not 100%.
[ding!]
But yeah, Windows 3.1 running under DOS 6.22 is the ideal environment for this setup,
which is why Apple bundled those with the system.
You get manuals and disks for both of them, some software for the Macintosh and DOS sides
of things to communicate with one another,
as well as driver disks for the DOS card’s graphics and sound.
And man is it strange to see Apple-branded Sound Blaster 16 disks, that is just surreal
even knowing the context.
And hearing proper Adlib music emanating from a Macintosh?
It feels wrong, but in the best kind of way.
[Jill of the Jungle plays]
And then there’s just the whole act of running PC applications and playing DOS games on a
mid-90s Macintosh, while simultaneously running System 7.
I understand it, I accept it, but it still feels like black magic to me.
That’s not to say it’s better in every way of course.
To begin with, Apple has always had a thing for single-button mice,
whereas PCs almost always had at least two buttons.
So you have to press the ‘equals’ key on the keyboard to right click here,
so that’s a bit of a pain.
Likewise for inserting and ejecting floppy disks, due to the way Macintoshes are Macintoshes.
Inserting a floppy in Mac OS mounts it as a volume,
so if you switch over into DOS, it can’t see it.
You have to insert the disk while in DOS mode for the A: drive to function at all.
And with no physical eject button you’ll be relying on the keyboard for that,
with Command+E ejecting disks.
[floppy disk ejects]
It’s similar with the CD-ROM, where a disc is only recognized if you insert it in DOS
first, and ejecting is yet another keyboard command.
Then there’s the fact that DOS runs slower than it would on a comparable PC with the
same 66 megahertz 486DX, something especially notable
if you haven’t populated the DOS card with its own RAM.
This is partially due to the memory sharing situation, where the Macintosh just uses the
system DRAM for video memory and then shares what’s left with DOS.
The resulting slowdown is especially notable with games like Doom, where it teeters on
the edge playable, running more like a lower-end 486 with half the speed this actually has.
Compare that to how the Mac port of Doom runs on the Power Mac side with the same amount
of RAM, and yeah, it’s apparent the DOS card has its limitations.
Again though, this is partially a memory restraint, so if you drop some RAM onto the card itself
then you can achieve significantly better results.
Though it’s still not as fast as a proper PC with its own graphics card.
And since the Mac’s only expansion slot is populated by the DOS card here, any PDS
video card upgrade options are off the table, so there’s only so far you can take this.
Again though, the 6100/66 DOS Compatible was made for a certain type of user
that demanded dual system integration above all else.
So while it’s not a gaming powerhouse, there’s a lot going for it in terms of communication
between the two systems.
Like the ability to quickly share text between Mac, DOS, and Windows 3.1.
Apple’s DOSCLIP and WINCLIP software lets you select, copy, and paste what you see on-screen,
including text and characters straight from a command line, and even certain compatible
images to and from the clipboards for Windows and Mac OS.
And then of course, there’s local file sharing.
In DOS, you can use the MACSHARE program to access Mac OS folders as drives.
And under Mac OS, you can easily mount the DOS drive container as a volume and manipulate
files and folders that way.
Speaking of which, yeah!
It uses drive container files to take care of hard disks, much like a software VM.
So if you’ve got the space for it, you’re free to keep multiple virtual hard drives
and partitions on-hand and swap them out using the PC Setup Control Panel.
This is also where you do things like select monitors, memory, serial ports, sound and
startup options, making it pretty painless to swap through a variety of different DOS
and Windows 3.1 setups.
So despite the hardware limitations and performance setbacks, the Power Mac 6100/66 DOS Compatible
has become one of my favorite mid-90s machines to play with
when I’m in the mood to think different.
As a fan of both DOS and Mac gaming from back then, having both in one case with the
ability to so quickly swap between the two is just awesome.
It’s not the only Macintosh to do this by any means, and it’s certainly not the fastest
machine on either the Power Mac or MS-DOS gaming front.
Each OS experience on its own here is rather middle of the road, really.
But when combined, it’s one of those “greater than the sum of its parts” novelties
from a fascinating period in retro computing, so I don’t even care.
This is a system that lets me play Glider Pro one moment and Commander Keen the next,
and that’s good enough for me.
[Secret of the Oracle music plays]
If you enjoyed checking out this ‘90s computer-y goodness,
then might I recommend some of these others I’ve uploaded.
Or subscribe to be notified of future LGR stuff, with new videos going up each week
about all sorts of retro tech.
And as always, thank you for watching!