View Full Version : QUestion about video options for an 8500.

05-09-2001, 03:42 PM
I recentlt found out that my 7500 board that was used to upgrade one of my 7200's is actually an 8500 as far as I can tell. It has the Sixty6 convolver and the 7187 DENC chips on-board, which the 7500 did not have. This is supposed to enable S-VHS or RCA video output for either mirroring or expanding the workspace, according to the ADC docs I read. Also assuming that I have the correct 8500-model I/O subpanel that plugs into the mobo near the PCI slots.

Here's the question: Can I use the 4MB VRAM on-board and run 2 monitors (one to the VGA connector and one to the RCA/S-VHS) as well as a PCI card to use 3 monitors with only one PCI card installed?

I understand that the output on the I/O sub-panel would be 640x480 most likely, but it still seems damn cool that I can have a 3 monitor setup with only 1 video card. Thanks for the help, if there is any to be had. Maybe I will go ahead and try it, but I would rather not move anything around too much at this stage of the game. Things have only recently found a semi-permanent home here. Just thinking ahead about which board to use for a project.

05-09-2001, 08:56 PM
Yes, you can output RCA or S-video to a TV or monitor while a monitor is hooked to the Mac video port. These would be identical outputs, however, and not allow you to move pallettes around or divide your desktop between them, like you could with the PCI-card connected monitor.

05-09-2001, 11:02 PM

Here's a bit from the ADC .pdf about the 75/8500:

"The Sixty6 custom IC and the 7187 DENC IC produce the second video output stream, which can either mirror the graphic display or display a separate image."

What exactly does that mean? Does it mean it can display a video output image, but not a desktop-type image? It leaves me a little baffled. I have used RCA outs before on Macs to mirror, and I am just wondering if the "separate image" is a separate workspace or not.

Thanks for the reply. Seems like this pair of extra chips on the 8500 do a bunch of neat things. GLad to have these mistakes falling into my lap. http://macgurus.com/infopop/emoticons/icon_biggrin.gif

05-09-2001, 11:13 PM
Hey Dog,

Maybe you're onto something. I have hooked up my 8500 to a TV before for fun but only mirrored. This could be pretty cool. I sold off my extra 2 MB VRAM, why don't you try it if you get a chance.

05-09-2001, 11:25 PM
Damn, I will. I had just kinda built-in my "7200-turned-7500-really-8500" into my desk for my server/2nd browser. I will see what I can come up with this weekend, once the daily grind releases me on Friday. http://macgurus.com/infopop/emoticons/icon_wink.gif

UPDATE: Oops...first I need the correct I/O panel. Mine only has video in, not out. Anyone have a spare? Or maybe Ebay is the place. Off I go!

[This message has been edited by Dogstarman (edited 09 May 2001).]

05-10-2001, 06:49 AM
Just unscrew the RCA connecter panel on the rear and two plastic covers will come off revealing a blank hole for the RCA out, but the S-video out is there and functional.

If nothing is attached to the video output, all 4MB of vram will be used for the logic board display. But if a cable is attached to an output (even if it is disconnected at the other end), 2MB will be used for logic board video, and the other 2MB for the TV out. They can be three independent displays. The TV out res are 320x240, 512xwhatever, and 640x480 PAL or NTSC.

It's interesting to note that native 320x240 videos play back the best on 8500s, no matter what the TV res is set at. For some reason, half-sized movies are always displayed as full screen without having to be scaled. Looks great. 640x480 movies play back fine also, but exhibit a slight flicker that movies scaled to a different size also show, when High Quality is not enabled. (No flicker when viewed on the monitor.) My only conclusion as to why this happens is that it was probably the only way to get decent quality video playback out of a relatively slow chip on a full screen TV.

[This message has been edited by despaxas (edited 10 May 2001).]

05-10-2001, 08:23 PM
This is pretty interesting. Still learning about my 8500 after all these years. I played around a bit last night but my 8500 is not near a TV so I tried to hook up my video camera as a second monitor instead. Indeed, when you connect to the RCA video out or S-video and the existing monitor is connected to either the stock motherboard video connector or to a PCI video card, the Monitors control panel and Control Strip settings modules reflect the presence of a second TV/NTSC/PAL device. The Monitors control panel does allow mirroring or extended desktop. Cool. I could not get an image on the vidcam (too many pixels I'm sure for the little LCD) and I only have 2 MB VRAM installed right now, but I could make stuff disappear into my extended desktop.

Hey Dog, one question. The 7500 MOBO had only video in (one of the few differences between it and the 8500). Are you saying that in your 7500 you have an 8500 MOBO which only has video in? Like an 8500 board and chipset was factory adapted to the 7500?

Dick Brillo
05-11-2001, 12:35 PM
Hi all,

You guys probably already know about this link...

...I know it is old, but the 'Print-to-Video Using Premiere' section talks about that pixel-doubling feature you mentioned, despaxas. It works great!

I bought an extra (2) 1MB VRAM chips off eBay so I wouldn't have to disconnect the computer screen and connect a TV moniter, and reboot, every time I wanted to print to video. Although, someone told me I could have both the computer screen and the TV moniter hooked up at the same time with only 2MB VRAM! He said the VRAM has to be in the correct slots for it to work, and often they were installed the other slots from the factory. Weird, I never tried it though.

Hope this is not repetitive.



Dick Brillo
05-11-2001, 08:29 PM
ahhh... I didn't mean to send that twice. Just to clarify, before the repetitive jokes start coming.


05-11-2001, 09:12 PM
OK. What I am saying:

I HAD a 7200/90. I bought a motherboard on Ebay that was advertised as a 7500. It came with the 75/7600 series video panel (RCA sound I/O and RCA video in and S-VHS video in). I installed it in my 7200's case. I have been using it for several months.

All my profilers showed it as an 8500, so I got curious and headed to the ADC site. I found all the chips that are on the 8500, but not the 7500 (basically 2). My "7500" has all the 8500-only extra chips. They are the same boards from the factory, just with a couple extra chips, allowing for RCA and S-VHS video out. The panel for the 8500's is different than the 7xxx series.

So I have a true 8500 board (sold to me as a 7500) with a 7xxx series A/V panel. I need the 8500 panel to use the video out feature. It's that simple. There's no hidden plugs anywhere. I would have been very curious about it when I got it if I saw them.

In all my scouring, I can only find the 2 chips I mentioned as being the difference between the 2 boards. Awesome find. Now I feel like I got a better deal, even.

So I guess the theory is true then...that with 1 PCI video card and the correct panel, I can run 3 monitors of workspace. Sweet. Thanks for all the info folks! http://macgurus.com/infopop/emoticons/icon_biggrin.gif

05-11-2001, 09:21 PM
as long as you have 4MB logic board VRAM, there is no reason not to go to Radio Shack and pick up a $75 NTSC display to run off the s-video out on the rear of the machine. Put your VideoPlayer window there, and use a VCR to tune cable television input, and watch cable tv on your Mac!


05-11-2001, 10:50 PM
Hey DB et al,

Now the two 'banks' of VRAM slots in the 8500 are starting to make more sense. You can probably use both video out modes with only 2 MB VRAM if you put one 1MB module in each 'bank'. Normally you would put both the 1 MB modules in the two slots of the same bank. 1 MB is just enough for 24-bit color at 640 x 480 rez.

05-12-2001, 12:07 PM
Those covers don't attach to the a/v board itself, so would not have been sent with them. I have 2 7500's, and a 7600, all have swapped 8500 boards. With the two external a/v panel screws removed, and the a/v panel pulled away from the rear, the two covers slide off. All of them revealed a hole (RCA spot) and an s-video out that functions with an 8500 board.

So Dog, are you saying the board you were sent has holes where the RCA out AND the s-video out are supposed to be? Very interestng. Out of curiosity, do you have a part #? The part number I have on a 7500 a/v board is 820-0609-A.

Sorry, I guess this is all moot since you have to get a new one anyway. If there isn't one for sale and you don't need RCA out, I have an extra panel somewhere that I don't need.

What a great surprise, though, that you were sent an 8500 motherboard. sweet. Wish something like that would happen to me. http://macgurus.com/infopop/emoticons/icon_biggrin.gif

[This message has been edited by despaxas (edited 12 May 2001).]

05-12-2001, 12:29 PM
The board I was sent comprised of the board, the A/V panel or board or whatever, the processor card and 2mb VRAM. The A/V that came with the board had only RCA video in and S-VHS in. No video out. I have both in and out (via RCA) on the A/V board. I removed the plugs (on the case) where video out goes upon mobo swapping. The P/N for the A/V part I have is 820-0610-A made in 1995, assembled in Mexico. I found someone who has the A/V thingie with no VHS out but it has a 4-pin S-VHS-style jack on the video out. Is that what you are talking about? Mine has nothing there except solid plastic and a round cutout where something should have been. http://macgurus.com/infopop/emoticons/icon_frown.gif So all I want is RCA out. S-VHS would be fine, I suppose, but I really hate going out just to pick up one cable or adapter. Looking around here for a friend who might have the full A/V board that they can surrender to me. Anyone kknow if I can solder on the appropriate RCA jack and be done with it? I have lotsa parts lying around.....hmm.....

[This message has been edited by Dogstarman (edited 12 May 2001).]

05-12-2001, 12:33 PM
Damn! They solder those metal shields on pretty well. 14 points of solder. It looks to me like there is more to it than adding in a jack. It's got a bunch of pads sitting there on the board.

05-12-2001, 01:32 PM
Wow, that IS interesting. 1995 here too. I wonder when and why the change was made. I would think that Apple would want to keep the a/v boards as similer to the 8500's as possible to cut down on manufacturing costs. So either yours is earlier, and Apple did change them to cut assembling costs, or mine was earlier and Apple pulled the S-video out for some reason. Oh well....

05-12-2001, 02:46 PM
I found that extra a/v panel and it is an 820-0610-A with the missing s-video out also. It must be out of the 7600 because I switched out the mobo and a/v (needed RCA out where it was going) when I first got it. Soooo, it looks like Apple pulled the s-video out later. Or maybe just taken out of the 7600's, and they sent a 7600 a/v board. Hell, if they sent an 8500 board instead of a 7500, they can't keep very good track of parts. My head hurts...

05-12-2001, 04:39 PM
If you're looking to part with that "spare" A/V board/box/panel/unit/doohicky, lemme know privately and I might snag it from you if the price seems right.

So I am thinking I have a 7200 case with a 7300 processor on an 8500 mobo with a 7600 A/V unit. OK, it's not so bad. Not a damn thing is from a 7500 (which is what I was sold). I just thought it was all from the same machine (or 2) when I bought the stuff. Thanks for all the help. http://macgurus.com/infopop/emoticons/icon_biggrin.gif

05-14-2001, 04:36 AM
that's hilarious!



it'll probably be your best Mac ever, too.


05-14-2001, 09:08 AM
Well, I found a fully-equipped A/V board last night and tried it out this AM. I can hook up 3 monitors (well, 2 monitors and one TV) and do like was suggested....watch TV on the TV through the Mac and have 2 other monitors of workspace all with one PCI slot filled. Nice. http://macgurus.com/infopop/emoticons/icon_biggrin.gif

Here's delusion #42 in my arsenal: Buy a Magma chassis and mount this board/thing INSIDE the chassis so I have a mega-slot A/V machine. Now, if only the things came down in price...maybe for MW NY? That'd be the cat's PJ's. http://www.macgurus.com/ubb/dance.gif

05-14-2001, 07:25 PM
i am a freak for running multiple displays and tv's and cameras and stuff off these units....we've been playing around a lot of with videoconferencing lately.....getting ready to set up a secure video system for the entire premises that can be viewed via the net.

i figure i will implement a system like this when i move to montana....and check on DE via the web, or viceversa, depending on where i am.

all you need, once you have Macs and cameras and stuff, is bandwidth.

how i am going to x-10 all this stuff......that is another matter....