Apple Monitor Hacks

9 replies [Last post]
Offline
Joined: Jan 23 2005
Posts: 595

I remember reading about how to hack the built-in monitor of the Colour Classic so that it would display a resolution of 640x480. I was wondering if anybody has done similar hacks with other Apple brand monitors?

I have a couple of 14" Apple monitors here that will only display 640x480. I really would like to be able to do at least 800x600, is this possible? Has anybody ever played with the vital organs of the old Apple 14 inchers?

Thanks

p.s. I would be using these monitors on a PM 7300 and PM 9500. Both of these machines have at least 2MB of VRAM or a video card with at least 2MB of VRAM. I know the computers can support higher resolutions. Is there anyway to trick the monitors into displaying higher resolutions?

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
Ex-parrot's picture
Offline
Joined: Dec 20 2003
Posts: 6835
I believe...

I believe that Apple monitors tell their host what kind they are based on a couple of otherwise unused pins in the VGA connector.

Perhaps if you were to somehow change the monitor's "ID" by pulling these pins out, or whatever, it would display other resolutions?

I'm reasonably sure that it wouldn't be able to display them anyway, but this could be worth a try.

Perhaps take a Mac->PC VGA adapter (with dip switches) and a PC VGA->Mac adapter and plug them both in line with the monitor? This ought to let you control the monitor's ID with the dip switches.

__________________

Michael

Jon's picture
Jon
Offline
Joined: Dec 20 2003
Posts: 2804
You can try software like Swi

You can try software like SwitchRes to make the system display modes that the monitor doesn't support. Beware that trying unofficial modes CAN cause real heardware damage to the monitors. Unless one is an EE or a video buff, any hadrware level mods would be risky and possibly dangerous if proper care and understanding are not known. Wink

__________________

I am not in this world to live up to other people's expectations, nor do I feel that the world must live up to mine. - Fritz Perls

dankephoto's picture
Offline
Joined: Dec 20 2003
Posts: 1900
no way without hardware mod

These things are hardwired to the 640x res guys, so no software hack will force another working resolution.

That said, I'm sure it's possible to do something, but I ain't the bloke with that info.

dan k

__________________

|| web page gone - curse you Comcast! | Applish goodies servers offline, sorry! |
» email macdan at comcast.net

Jon's picture
Jon
Offline
Joined: Dec 20 2003
Posts: 2804
SwitchRes will force the syst

SwitchRes will force the system to output any res you select, but whether the hardware will accept it or fry is up for grabs.

__________________

I am not in this world to live up to other people's expectations, nor do I feel that the world must live up to mine. - Fritz Perls

dankephoto's picture
Offline
Joined: Dec 20 2003
Posts: 1900
re: SwitchRes will force the syst

Yeah Jon, but the OP wants to get a coherent output on the display. There's no tricking possible with the old 640x displays, no matter what you feed it. They're hardware locked to a single specific res and refresh, nothing else will do.

As for frying, not to worry, it's pretty difficult (impossible?) to fry those displays with an unusable video input. It'll just sit there flickering or blinking or just blank.

While there it's possible in theory to mod the displayed resolution, I'll suggest it's hardly worth the bother. Quality 14" multisynch are a dime a dozen, why give yourself a headache. Ooops! I forgot, this is AF. Never mind! Tongue

dan k

__________________

|| web page gone - curse you Comcast! | Applish goodies servers offline, sorry! |
» email macdan at comcast.net

eeun's picture
Offline
Joined: Dec 19 2003
Posts: 1891
Re: re: SwitchRes will force the syst

dankephoto wrote:

I forgot, this is AF. Never mind!

Hey, are you saying there's something wrong with my plan to turn an LC II into a combination terabyte server and forced-air furnace replacement?

__________________

"Give a man a fire, he's warm for a day. Set a man on fire and he's warm for the rest of his life."
(Terry Pratchett)

Offline
Joined: Dec 20 2003
Posts: 354
One example of success

I was going to get around to posting about this in the Color Classic forum, but I've been super busy lately- I recently got a Macintosh Color Display (M1212, fixed resolution at 640x480@67hz) to sync with a cube at 800x600@56hz. I simply left all the sense lines unconnected, since OS X defaults to 800x600. I'd tried this kind of thing many times before, and always got frustrated- but my mistake was trying to get the sense lines to work, fiddling with adapters- turns out the key is to not try to outsmart the equipment, and just let the default do the work.

There is a little bit of distortion of the top of the menu bar, a la the LC575 SVGA mod.

Oddly enough, it will *not* sync at VGA. Which I find kind of odd, since the LC575 mod will, and I've assumed that the analog boards are related since they use identical tubes.

This is a 14" model, but some 14" models had non-trinitron tubes and presumably different electronics, so YMMV.

__________________

"One day I shot an elephant in my pajamas. What he was doing in my pajamas I have no idea."

Eudimorphodon's picture
Offline
Joined: Dec 21 2003
Posts: 1204
Re: One example of success

dead_elvis wrote:

I recently got a Macintosh Color Display (M1212, fixed resolution at 640x480@67hz) to sync with a cube at 800x600@56hz.

Did the flickering slowly fill you with dark, violent, homicidal thoughts? Computer CRTs displaying at anything less then 70Hz or so tend to do that after prolonged exposure. ;^>

--Peace

Offline
Joined: Dec 20 2003
Posts: 354
Re: One example of success

Quote:

Did the flickering slowly fill you with dark, violent, homicidal thoughts? Computer CRTs displaying at anything less then 70Hz or so tend to do that after prolonged exposure. ;^>

--Peace

The difference even between 60 and 56hz Is pretty amazing. I don't think it bothers me as much as some people, but also the goal is to just have something useable. I wouldn't stare at it for hours on end, for for light use here and there it's fine. When hacking Color Classics there are times when you have to just be happy with whatever you can get!

If anything, all this playing around with VGA/SVGA vs. 67hz really makes me appreciate Apple, even if the non-standard stuff drives us nuts. Back in the mid-90s, I didn't understand why Macs always looked better than Windows PCs; crisper image and more vivid colors. Windows always looked sort of washed out to me. Once I got a crappy cheap NEC monitor, I found out a Mac could look just as crappy as a PC. Higher refresh rates and trinitron tubes will do wonders. Maybe I was ignorant, but I probably didn't know any less than the average joe.

__________________

"One day I shot an elephant in my pajamas. What he was doing in my pajamas I have no idea."