Dan Knight
and Kris Finkenbinder - 2007.07.25
Kris Finkenbinder says:
Hi Dan,
I have been blessed with an opportunity to mess around with an
iMac G3 in order to move a stalwart family of Mac users into the
21st century. During the entire lifetime of this machine, they've
been using Mac OS 9.0.3(!), and they have several "classic"
applications from antiquity that they've been using for years and
want to keep using, so it wasn't too difficult to talk them out of
springing for a brand new Intel iMac which (surprise!) would not
run any of their old applications.
And no, there are no OS X replacements for things like PageMaker
5.0/6.5 and a couple of the other oddball applications they've been
using for years, although I'm helping them move on in other areas.
So I get to install a big (and quiet, what's with old screaming
hard drives?) hard drive, max out the RAM, and set them up with an
OS X + Classic environment system that will work just great for
them.
The machine is one of the iMac
DV+ models, it seems to be the 400 MHz version that came with a
13 GB hard drive and a translucent "graphite" case. I was overjoyed
to find out that it had FireWire ports and a VGA-out port. A couple
of years ago I upgraded a pair of earlier 350 MHz iMac models that
had neither of these port options, which made things much more
complicated.
At the same time, I found out about the iMac G3
firmware issue the hard way after merely booting from an
OS X installation disc. I saved one in time with the 4.1.9
firmware update, but it took me a year or two until I finally
learned how to resurrect the one that completely died on me. I
finally did work some sort of magic involving a lot of rebooting
and drive swapping, and now they are both chugging away just fine
in an office running Panther [OS X 10.2.x] with fast 80 GB hard
drives and 1 GB of RAM.
I will probably update them to Tiger sometime soon just for
continued software compatibility and access to security updates
during the coming reign of Leopard. How unfortunate that Tiger will
be the last version of OS X they can run, unless the
XPostFacto people can work some magic of their own.
Anyway, my question to you, your staff, and/or your readers
concerns the capabilities of VGA-out port on the back of this iMac
DV. The internal display of this machine is, of course, getting a
little dim and fuzzy from years of use, and really only looks
acceptable at 800 x 600, whereas it can natively support 1024 x 768
on both the internal and external display. I happen to have a
decent 17" CRT monitor that I can sell these people for next to
nothing. I tested the port, and it does work, and it looks great at
its full resolution on the larger external display. I'd like to
offer to set them up with this external monitor. Having the higher
resolution and larger display really enhances the usability of the
system, especially for web browsing.
Since this VGA-out port is only capable of mirroring the
internal display, there will be no point in having the iMac taking
up space on top of the desk along with an equally massive 17" CRT
monitor. Being able to stick it under the desk would be great; they
have plenty of room to do this without crowding it or kicking it,
and with their NewerTech
miniStack v.2 combo USB/FireWire external drive they will still
have easy access to all the USB and FireWire ports they need.
At the same time there is no reason to have the internal display
constantly running, using up electricity, creating excess heat,
light and static while displaying the same image as the external
monitor. Unfortunately, the iMac doesn't seem to see the external
monitor in any way that would allow it to be controlled separately
from the internal display. Brightness controls, energy saver
preferences, screen savers - everything is software based and will,
of course, affect the external and internal displays
identically.
So, starting from this information, I have a couple of
questions. I've Googled around but didn't come up with any relevant
answers to these specific issues:
- I am wondering if anyone knows of some obscure OS X system file
or command (or Open Firmware command) that could be used to
selectively (and reversibly) disable only the internal display
while still allowing uninhibited use of the external monitor. I
know that the internal display can be physically disconnected from
the logic board, but I am loath to open the top cover and make that
kind of physical change because it would be difficult for the
owners to reverse.
A software command would hopefully be much easier to
change back if necessary without dismantling anything, and I know
that with its strong relation to Unix some interesting things can
be done in OS X with hardware sometimes just by issuing a
shell command or two, like "sudo mv /dev/internalvideoport
/dev/Xinternalvideoport". But, and I'm making only a semi-educated
guess here, I'm guessing that this will be possible only if the
operating system or firmware sees the internal and external display
as two separate devices at some deeper level. No indication of this
shows up in the display preferences.
- If I do physically disconnect the internal display's video
cable, is there some kind of circuit I need to keep connected in
order to avoid the "headless Mac" syndrome, or will it still work
okay as long as the external monitor is connected when it boots up?
Is the connection between the internal and external display ports
just a physical splitting of wires, or is there some kind of
circuitry in between the two that will cause me problems?
- I'd also like to disconnect the power to the internal display.
Is there any reason why this would cause any problems? Is there any
chance the system will refuse to boot up or refuse to activate the
external VGA port if the internal display power is
disconnected?
- I first read about the Dr. Bott gHead
VGA adapter a couple of years ago, when researching running a
Power Mac G4 as a headless server. I would be very interested to
know if anyone has hooked up a gHead to the VGA-out port of an iMac
G3, either with or without the internal display disconnected. I'm
wondering if the gHead would allow the external monitor to be
driven at even higher resolutions like 1280 x 1024, beyond the
supposed maximum 1024 x 768 resolution on this machine. Or would
the gHead device just be superfluous with an external monitor
hooked up?
I can't seem to find any information on the actual maximum
resolution of the built-in ATI Rage 128 VR (8 MB, AGP 2x)
video chipset, so I have no clue whether it is being restricted to
1024 x 768 only by virtue of being connected to the internal
display, which may be telling the graphics system that it can't
display any higher resolution, or if there is some hardware
limitation in the chipset itself. All the information Google came
up with seemed to relate only to retail AGP cards.
I have read somewhere that the gHead is capable of convincing
most video cards to allow the use of many more resolutions and
refresh rates than they would normally allow when directly
connected to most VGA monitors, making it useful even for
non-headless usage. Has anyone tried it on a G3 iMac that you know
of? If this little machine could support 1280 x 1024 on an
external, that would be a fantastic enhancement. I'm sure a
widescreen monitor is out of the question with such an old card,
but SXGA support would be great.
Anyone who has more information on this can email redbear (at)
redbearnet (dot) com, with "iMac G3 VGA" in the subject line to
help me identify it (I get a lot of junk mail).
Thanks again for your helpful website. Too bad about Leopard and
G3s, but we'll see what the situation looks like a year after
Leopard is released.
Kris Finkenbinder
(the long-winded G3/Leopard ranter)
Hi Kris,
Congratulations on your successful updating and
resurrection of these iMacs.
To the best of my knowledge, there is no way to
support two separate displays using the ATI Rage 128 VR inside
these iMacs. Whatever is displayed on one monitor will be mirrored
on the other.
There should be no reason you can't disconnect the
internal video connector and power supply, and after doing so you
may be able to select resolutions the iMac's internal display
doesn't support. Either way, a 17" display at 1024 x 768 should
look a lot better than a 15" one at the same resolution.
I don't know much about the gHead adapter, but I'd
suggest disconnecting the internal display and trying an external
monitor before investing in the adapter.
Maybe some of our readers can share their
experiences as well.
Dan
Thanks, Dan. There's nothing better than bringing a computer
that you thought was dead back into a useful life, especially when
it can run OS X.
Well, yet another "ancient" iMac G3 is running Mac OS X
shockingly well after a simple hard drive and RAM upgrade
procedure. I already tried the very thing you've suggested, which
was just disconnecting the internal display and attempting to boot
with just the external VGA display connected. Unfortunately the
machine wouldn't even boot up without the internal display cable
attached. Or it sort of seemed to power on but never really seemed
to come up in any useful way, and never activated the external
monitor. It seems that the CRT iMacs were designed to require the
internal display to be connected and functioning before they will
work properly.
I don't have the electrical/wiring skills or special connectors
necessary to do the sort of hardware modifications that others have
done in online articles I have found in order to bypass this
limitation, so I finally gave up on the idea and just told the
owners they would have to cover the built-in display and live with
it as the price of having a much better, higher-resolution picture
on the external display. They seem to be fine with that so far. The
improvement is really stark when comparing the two displays,
especially in terms of accurate color and brightness. The internal
CRT is too dim to really display white anymore, no matter how much
you fiddle with color profiles.
It also seemed like in all those online articles where someone
built their own custom video adapter cable they had a very
difficult time getting a clear image on an external monitor, and
that's exactly what I didn't want, so that was another reason I
gave up on even trying to make my own cable. I have no doubt that
the gHead would make no difference whatsoever unless it could
either be hooked up directly to the internal display connector - or
the internal connector could first be patched in a way that would
accomplish the same purpose and fool the system into thinking a
display capable of higher resolutions was connected internally
(which would thus theoretically enable the same high resolutions on
the external connector even without a gHead).
I'm actually kind of surprised that none of the people who
really understand how to do these things (and have the wiring and
soldering skills required) haven't tried using a gHead. It would be
absolutely fascinating to find out that all those old iMac G3s (350
MHz and higher) could have their aging internal CRTs completely
disconnected or removed and support using an external display at
1280 x 1024, or even a low-res widescreen resolution. The machines
themselves will continue to be useful for basic word processing,
email, Web browsing, and other simple office or household tasks in
many cases for long after their internal CRTs have failed or faded
into unusability. With 8 MB of video RAM there really isn't
any technical reason for the card not to be capable of at least a
standard aspect resolution of 1280 x 1024. If I remember correctly,
even back in the day of 1 MB video cards they could often run
at that resolution in at least 256 color mode if not better.
Of course, even if higher resolutions are really impossible in
hardware, it would be helpful to have an easier way to disengage
the internal CRT without major surgery and handmade special video
connectors (along with the "minor" task of modifying the power
supply system if you actually want to physically remove the CRT). I
don't suppose anyone out there is interested in making small
quantities of those special video connectors for sale? There are a
lot of iMac G3s out there, and their CRTs are getting very old,
dim, and fuzzy. I'm sure many of the CRTs have already failed,
causing the whole iMac to be unnecessarily declared dead and
discarded. That's always a sad fate, especially for a Mac, when the
machine could probably still be serving a purpose for years to
come.
Ah well, at least there are also a lot of G4 Power Mac systems
out there to keep running into the future.
Cheers,
Kris Finkenbinder
Kris,
I've been inside the old tray-loading iMacs many
times, and all you need to make them work with an external display
is a Mac DB-15 to VGA adapter. This makes it relatively easy to
disconnect the internal display and wire in an external monitor.
I've even heard of people mounting an iMac motherboard inside a 20"
display.
Not so with the slot-loaders. One modder,cryogenius, managed
to make a VGA cable to connect to the motherboard video on a
slot-loading iMac and soon discovered that monitors with cables
over about 3' long had serious sync problems. From your email, it
seems this is the only way to bypass the internal display - or
remove it entirely.
If anyone makes a slot-loading iMac motherboard
video-to-VGA connector, I haven't heard of it. It would be a great
way to salvage old G3 iMacs after monitor failure, and it may well
allow higher resolutions than the internal 15" display. I've sent
an email to cryogenius asking if he's been able to go beyond 1024 x
768.
Dan
Aaron (a.k.a. Cryogenius) writes:
...after doing one of these conversions, it's
possible to use something like Super
Res or SwitchRes
and experiment with resolutions and refresh rates and see what
happens. I wouldn't recommend experimenting with it on an
unmodified iMac, however, because I suspect that something in the
original power supply or display board can be blown up fairly
easily . . . and then the conversion becomes a
necessity!
Hi Dan,
Press releases often make it sound like a product is some new
item exclusive to that vendor, and sometimes it is, like with
NewerTech's products, so I was very pleased to find an alternate
source for that same fantastically adaptable piece of hardware with
better pricing. If I had the cash, I think I would have already
bought several of those enclosures. Quad interfaces on a notebook
drive enclosure? Talk about covering all the bases. Now we just
need one that also has a Gigabit Ethernet port and built-in SMB/AFS
file server capability. Seeing such a device would honestly not
surprise me at this point.
The iMac has been safely back in the owners' hands for a while
now with a 160 GB internal drive (of which it can see 128 GB, of
course) [see How Big a Hard Drive
Can I Put in My iMac, eMac, Power Mac, PowerBook, or iBook? - ed] and a NewerTech
miniStack v2 external drive for physically redundant backups. That
should take care of them for backups, which are handled on an
automatic schedule by
SuperDuper!
I didn't have the time to mess with the graphics issue any
longer, so they will just have to make do with the improved 1024 x
768 on the external monitor. That by itself makes a world of
difference compared to what they used to have.
I also set them up with a powerful Belkin UPS, but I have been
irritated to find that unlike the other Belkin units I've had
experience with, this model has very poor compatibility with
Tiger.
The UPS does not show up in the Energy Saver preferences, even
though it has a USB connection and the USB bus shows that there is
a "USB to serial converter" plugged in when I look in System
Profiler. The problem seems to stem from the unit being one of the
"Enterprise" models rather than a lower-end consumer oriented
model. The consumer models show up in System Profiler as "UPS" on
the USB bus. How about that. Apparently the Enterprise models use a
different communication protocol. Of course.
The software from Belkin is Java-based and looks as if it was
written for 10.2/Jaguar and hasn't been updated since. The software
agent doesn't load at startup, probably due to the changes in the
startup system in Tiger. I was able to get it to load up by using
Lingon to create a
launchd plist. That allowed me to at least run the monitoring
software, check the status, and change some settings.
The final problem is that the software seems totally incapable
of shutting down the system on its own. It brings up messages
saying it's telling the workstation to shut down, but nothing ever
happens. Then after the designated 2 minutes given for the
workstation to shut down, it powers itself off with the computer
still up and running. Very bad behavior.
So that's how I spent my Saturday evening, struggling with a UPS
unit that should have been plug-and-play with OS X. This has
been one of my biggest frustrations, trying to find hardware that
actually works with OS X out of the box. Nowhere have I found
any list that covers which UPS models from which manufacturers will
actually work with the built-in UPS recognition in versions of
OS X from 10.3.3 onward.
APC is always at the top of everyone's list, but Belkin models
are typically almost half the price for the same capacity. I have
no idea about other brands, and even with APC you're rolling the
dice because they have multiple different communications protocols.
Some work with OS X by default and others will require the APC
software, which apparently is much better than Belkin's
offering.
This compatible hardware issue extends to other hardware too,
like which digital cameras and scanners are compatible with Image
Capture. I just recently learned that Image Capture has apparently
had the capability for a while now of controlling some digital
cameras and sharing access to scanners and cameras over a network.
This could potentially be very useful in many small offices, where
you could not only have a central print server but also a central
scanner server that everyone could access. But where is the
compatibility list that definitively shows which hardware will work
with Image Capture and allow these capabilities? The lists found on
Apple's website are pathetically short and never get updated, and
I've found no user lists regarding Image Capture compatibility.
Then there are add-in cards for Mac notebooks and desktops.
Which types of cards are still Mac-specific, besides video cards?
If something on Newegg.com
doesn't explicitly state that it's Mac
compatible, will it still work? USB, FireWire, SATA, ethernet cards
- are they all compatible by default? In many cases, yes, but there
is no reliable way that I know of to determine for sure besides
trying it, so I tend to stick with ordering such things from places
like OWC so that I know with
certainty that the device will be fully compatible with a specific
Mac.
I do know that most wireless networking and EVDO cards are still
not Mac-friendly. Some USB network adapters work, most don't. So on
and so forth. It's a mine-field of guesswork.
This is really one of the biggest problems I'm facing as a
proponent of Apple computers, and I have yet to find a reliable
source of hardware compatibility information. There seem to be at
least three things happening in the Mac world that contribute to
this problem.
One is that Apple does absolutely nothing to help users figure
out exactly how certain parts of the system work (like the hidden
UPS compatibility) and describe exactly what hardware
specifications to look for that indicate compatibility. If you
happen to plug in a compatible UPS it shows up and works as if by
magic. Otherwise, it doesn't. Are there specific UPS protocols that
are compatible? Who knows?
Second, companies that make and sell products for Macs don't
bother to specify which products are actually 100% functional with
OS X. Even when they do indicate compatibility, it is never to
be trusted. I got this Belkin UPS from MacMall; one would think it
would actually be compatible with Macs.
Third, the Mac users that do have knowledge about which hardware
works just seem to assume that all Mac users have this information
and don't bother to try and catalog the specifics anywhere. So
adding hardware internally or externally to your Mac ends up being
a crap shoot in many cases. Every individual Mac user is on their
own.
Just ranting a bit, of course, but if you do know of some good
solid sources of hardware compatibility for Macs and Mac OS X,
especially regarding specific UPS models, I would be very glad to
hear about it. It causes me massive headaches when I'm trying to
get my clients set up with the right hardware accessories at
reasonable prices. A good UPS with the ability to automatically
shut down your computer is just one of those things I consider a
necessity, like a backup drive, and it pains me to no end to be
unable to make a reliable recommendation on affordable UPS models
that will actually work without an epic struggle with broken
software.
Cheers,
Kris F.
Kris,
Thanks for all the info. I'm glad the iMac is
working so nicely with an external 17" display. Too bad Apple never
thought of including a way to disable the internal monitor. And
SuperDuper! is a great choice for backup. I've been using it for
years.
I've run into the same problem with UPSes. I have
a nice Tripp Lite one under my desk, and it's connected to my Power
Mac via USB. Energy Saver recognizes it, but I don't trust the
power level readings. Another problem is shutting down if you have
a program with an open, unsaved file. There should be a default
behavior for saviing with a special name. Instead, the Mac simply
refuses to shut down, undermining the utility of auto shutdown as
UPS power diminishes.
Another bugaboo is UPS power ratings. As UPSes
have become smaller and cheaper over the years while seeming
offering the same level of power, something must be up. (As I have
so many devices, I have a second, smaller UPS to power my wireless
keyboard, USB hub, and a few other smaller peripherals.)
Hardware compatibility is a big bugaboo for Mac
adopters. At least prior to the Intel transition, you had to make
sure a video card was designed to work with the Mac. USB cards that
don't specify "Mac compatible" are a crap shoot. Some ethernet and
WiFi routers and switches don't support the AppleTalk protocol,
which is important for older Macs, older printers, and the
like.
Someone ought to create an online database or wiki
for this.
Thanks for helping other enjoy the Mac experience,
even if the process of getting everything working for them is
sometimes frustrating.
Dan
Dan Knight has been publishing Low
End Mac since April 1997. Mailbag columns come from email responses to his Mac Musings, Mac Daniel, Online Tech Journal, and other columns on the site.
