Which Macintoshes, NuBus Video Cards Only Do “Sync on Green”?

[jdmcs]

Based on information that I found online, the on-board video on the Macintosh IIci and Macintosh IIsi only support “sync on green” mode, which is a problem if you don’t have a monitor/scaler or other video device which supports this mode.

Well, I have a IIci, but nothing old enough to do sync on green, so I have so far been unable to get further in troubleshooting than the chime.

If these two Macs (or certain revisions only do “sync on green”, then I suspect there could be other Macintoshes and/or NuBus cards out there that also didn’t bother to implement other sync modes.

Does anyone know of any other “sync on green” only Macs or NuBus video cards out there? I’d like to not waste money on video cards that won’t work for me, or know I’ll need a video card for certain Macs.

Source: Notes section of https://wiki.preterhuman.net/Macintosh_IIci
“As the video system in the IIci is said to be the same as found in the Macintosh IIsi you may need a sync-on-green compatible monitor.”

 

[Volvo242GT]

Even the Centris 650, Quadra 650, and Quadra 800 are sync on green machines.

 

[jdmcs]

Even the Centris 650, Quadra 650, and Quadra 800 are sync on green machines.

View attachment 3833

Which Dell monitor is that (assuming you're not using some sort of adapter to separate the sync from the green)?

 

[Melkhior]

Well, I have a IIci, but nothing old enough to do sync on green

I suggest trying all monitors with VGA inputs that you own if you haven't already. Some monitors don't advertise sync-on-green yet seem to work. I have an IIyama E2473HS that will display a picture from a IIci (not a very pretty one, but more than enough to check the system).

A lot of the early 17" LCDs are also likely to support SoG, you can try to locate a cheap second-hand ones (I have a couple of Samsung SyncMaster 713BM for that very purpose, works fine with old Suns framebuffer and a Quadra 650 internal video).

Edit: s/you try/you can try/

 

[Volvo242GT]

Which Dell monitor is that (assuming you're not using some sort of adapter to separate the sync from the green)?

A Dell UltraSharp 1908FP. Works great on my G3, but doesn't work well with either the IIci or the Centris 650. Adapter is a Sony MacView LX.

 

[jdmcs]

I suggest trying all monitors with VGA inputs that you own if you haven't already. Some monitors don't advertise sync-on-green yet seem to work. I have an IIyama E2473HS that will display a picture from a IIci (not a very pretty one, but more than enough to check the system).

A lot of the early 17" LCDs are also likely to support SoG, you try to locate a cheap second-hand ones (I have a couple of Samsung SyncMaster 713BM for that very purpose, works fine with old Suns framebuffer and a Quadra 650 internal video).

Turns out I have several and didn’t realize it because I thought they were too new. I had grabbed some Dell LCD monitors they were scraping at work and their data sheets say they do sync on green. If my IIci power supply wasn’t currently disassembled for re-capping, I would put it to the test.

I still wanted to compile the list of sync on green hardware. I prefer to do direct video capture, and for that sync on green simply will not do.

 

[Elemenoh]

@jdmcs where did you read these models only support sync on green?

The IIci Technical Procedures doc is a little vague but seems to indicate it might support different types of sync signals.

When a monitor is connected to the built-in video ports, the monitor will ground certain pins on the connector which allows the RBV to identify the type of monitor connected. The RBV automatically selects the appropriate pixel clock and sync timing parameters. If an unknown monitor is plugged in or no monitor is plugged in, built-in video output is halted.

I didn't see anything in there stating that only sync on green is supported, but maybe that's implied?

 

[jdmcs]

@jdmcs where did you read these models only support sync on green?

The Higher Intellect Vintage Wiki states that the IIci shares video chips with the IIsi, and this may need a sync on green monitor: https://wiki.preterhuman.net/Macintosh_IIci

As the video system in the IIci is said to be the same as found in the Macintosh IIsi you may need a sync-on-green compatible monitor.

Chris Xodium’s Retro Haus on YouTube didn’t want to go out to his garage to get his sync on green monitor to test his IIsi:

And from the pickle’s Low-End Mac FAQ: https://www.jagshouse.com/lowendmacfaq.html#Q2.1.6

2.1.6 - What monitors will work with my IIci/IIsi?

The IIsi and IIci, which have the same video subsystem, cannot drive a standard VGA monitor. However, any monitor supporting a 67Hz refresh rate, sync-on-green, and the proper horizontal and vertical refresh rates will work. This includes many Sony monitors and the Apple Portrait Display. Apple's multisync monitors such as the Multiple Scan 15 do NOT support sync-on-green, and will not work properly with the built-in video. The Apple Two-Page Display is also incompatible with built-in video on these two Macs.

Some Mac-to-VGA monitor adapters can properly separate the sync signals of monitors that do not sync on green, thus enabling otherwise incompatible monitors to be used with the IIci or IIsi (at a price, usually around US$50). The Apple Developer Hardware Tech Note #8 has pinout information for the IIci and IIsi DB-15 video ports if you want to make your own adapter.

So this is how I concluded that the IIci’s video is in common with the IIsi, and that it, too, is sync on green only.

Though I may have other issues with the IIci as well…

 

[jdmcs]

And according to 68kMLA at https://68kmla.org/bb/index.php?thr...with-a-non-apple-multiple-sync-monitor.40039/:

VGA is a H+V sync standard and just about every monitor requires it. Some select VGA monitors (including the OSSC) support Sync-on-Green (anything Sony) or composite sync on the H-sync pin 13, but they are far from common. Without a sync seperator, getting ANY video on a IIci,IIsi,IIvi,IIvx and the early Apple NuBus video cards would be impossible for these adapters.

Great, the OP here only specified “early Apple NuBus video cards” here without naming them. But I suspected that some existed.

Which is why I wanted to make sure this thread captured the names of the Apple products which only do sync on green…

 

[Volvo242GT]

@NJRoadfan Do you know the specific early NuBus video cards that don't work without sync separation with VGA to Mac adapters?

 

[davewongillies]

My Quadra 700 only outputs sync on green as well.

I managed to pick up a second hand Software Integrators 7053 sync separator for $20 on ebay. Regular price for those are $139 on the manufacturer's website: https://si87.com/epages/3738123e-8b...23e-8b74-40b2-bd96-ddff0f19d352/Products/7053

 

[Jamieson]

This guy made his own adapter to get his IIci connected to an LCD monitor VGA port.

It's not clear in the video if he is using the motherboard video connector or a NuBus display card.
Also not clear if he was using a "sync on green" monitor. But it's working for him.

It looks like he is using this info:
https://old.pinouts.ru/Audio-Video-Hardware/MacVideoToVGA_pinout.shtml

If the IIci is putting the negative going sync pulse on the green video signal, it might be enough to take that green video signal and send it to the VGA /HSYNC pin. If the IIci is combining H and V sync pulses, that would likely require some external circuitry to separate into /VSYNC and /HSYNC that VGA requires.

 

[skate323k137]

I still wanted to compile the list of sync on green hardware. I prefer to do direct video capture, and for that sync on green simply will not do.

I doubt it will help for capture, but the PS2 console in 480P RGB mode is VGA sync on green. There were lists of PC CRTs that work and don't. I have had viewsonics that work and do not work, and I think all the sony's I've owned have worked.

If the signal is at least 640x480, I would encourage you to get an Extron SS 200 sync stabilizer. It can strip sync on green and go to "normal" VGA/Sync. I have tested a lot of SoG sources through the Extron, and I have not found a VGA monitor that won't take the output. The only downside is only one side has a d-sub, both sides have BNC. But VGA to BNC breakout cables work fine.

Extron SS 200 Sync Stabilizer Features​

• Input: Female BNCs for RGBHV, RGBS, RsGsBs, or RGsB
• Dual output: Female 15-pin HD and female BNCs for RGBS or RGBHV
• 300 MHz (-3 dB) RGB video bandwidth
• Compatible with any analog RGB signal with horizontal frequency between 30-145 kHz and vertical frequency between 30-170 Hz
• ADSP™ - Advanced Digital Sync Processing
• Strips sync on green
• Horizontal shift control
• DIP switches for horizontal shift, restoration or removal of serration pulses, and input termination

 

[Jamieson]

The IIci schematic shows the motherboard video connector (J6) with VSYNC on pin 12 and HSYNC on pin 15. (There is also what looks to be a combined H and V sync on pin 3.)

The wiring diagram for the DIY adapter seems to agree with the standard VGA pinout and the J6 pinout from the IIci schematic.

I think that's what the guy in the video is doing to make it work. He may have changed the ID3, ID2, and ID1 pins to tell the IIci onboard video to use a particular mode, but it seems like this totally passive solution should work.

I guess one question is on "Mac to VGA" dongle things, the ones with all the DIP switches -- are they wired up like this? Do the DIP switches just reconnect Mac pins 4, 7, and 10 in different ways to force the Mac into different modes? Or the DIP switches change the connectivity of other signals?

 

[retr01]

Hello everyone!

Yeah, sync on the green can be a challenge these days.

I use a Samsung SyncMaster 710N monitor connected to my IIci via RGB/VGA converter adapter with DIP switches. Here are the DIP settings I use:

IIci onboard video: 1, 6, 7, 9​

Radius Precision 24AC: 1, 4​

​

If you want HDMI, get an Extron RGB HDMI 300 A or RGB2HDMI. I use the Extron with my Apple IIGS, which works very well. I plan to use the RGB2HDMI with my SE/30. I will test it on my IIci, too.

Cheers!

 

[Eric's Edge]

Interested in hearing if the inexpensive multi-switch adapters worked or not. I'm getting a IIci in the near future and would like to find a solution that doesn't require hard to find monitors and/or expensive video scaler equipment.

 

[skate323k137]

Most sony displays support sync on green in my experience, but yeah, it's nice not to have to rely on the display supporting it.

 

[retr01]

Interested in hearing if the inexpensive multi-switch adapters worked or not. I'm getting a IIci in the near future and would like to find a solution that doesn't require hard to find monitors and/or expensive video scaler equipment.

This one is what I got.

HD15 VGA Monitor Female to DB15 MAC Male Converter Adapter w/ Dip Switches | eBay

This adapter is used to connect an VGA/SVGA Monitor to a Macintosh Computer. The MAC Computer has a two row DB15 female connector. The PC Monitor has a 3 row high density DB15 male cable. 1 x DB15 male.

www.ebay.com

Cheers!

 

[GondolinOnMyMind]

The IIci schematic shows the motherboard video connector (J6) with VSYNC on pin 12 and HSYNC on pin 15. (There is also what looks to be a combined H and V sync on pin 3.)

The wiring diagram for the DIY adapter seems to agree with the standard VGA pinout and the J6 pinout from the IIci schematic.

I think that's what the guy in the video is doing to make it work. He may have changed the ID3, ID2, and ID1 pins to tell the IIci onboard video to use a particular mode, but it seems like this totally passive solution should work.

I guess one question is on "Mac to VGA" dongle things, the ones with all the DIP switches -- are they wired up like this? Do the DIP switches just reconnect Mac pins 4, 7, and 10 in different ways to force the Mac into different modes? Or the DIP switches change the connectivity of other signals?

What should the diode in this be like?

 

[3lectr1c]

Just saw this thread, seems like the perfect thing to put on my website as a list! Would be useful to know for sure.
So far I've gathered:
IIci
IIsi
Q700
Q/C650
Q800

Any others only do sync on green?