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Using an LCD monitor on a IIGS

D

Drken

Experienced Member
Joined
Jan 13, 2009
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Charlotte NC
I know this has been discussed in the past, but I can't seem to find the threads (probably ignorance on my part). I have a board on my IIGS which allows me to connect the IIGS to an LCD monitor. The results are acceptable, but still not very good.

On eBay, there is a seller who is selling a unit (here) advertised as for the IIGS in the ad title, but when you read through the ad text, the IIGS is not mentioned at all... nor is Apple itself. I contacted the seller & asked specifically if they have tested the device with an Apple IIGS and here is the response I received (the same ad appeared with two different titles):

"These two listings function exactly the same. Important requirement to use this product is the source device must be outputting CGA signal at Horizontal 15.73, or, 15.62 KHz + Vertical 60, or, 50 Hz Non-interlace. The same requirement goes for Apple IIGS. Based on the feedback we received, some Apple IIGS user has met the frequency requirement, and some did not. Therefore, please find out about the signal frequency before purchasing."

My question pertains to the last half of the response: Does it make sense that some Apple IIGS units would meet those output specs, and others wouldn't? Would 0.11 KHz difference matter, and what are the chances that there is this much variation in IIGS units?

In refurbishing Apple IIs these past few years, I have seen what, to me, is an extraordinarily high variation within a model. Much of that variation appears to me to be the result of exactly where & when a component was manufactured. One small example: on some Apple IIc cases, the top and back panels are one single, molded piece, whereas in other IIc units, the back plate is a separate piece from the top of the case, held together with several snap-hooks. In another thread here, someone else pointed out several differences in IIe motherboards. Of course, you would expect some differences to crop up over time, much as you would in minor variations in software (eg., v 3.01 vs 3.02). But would there be such variation within an Apple IIGS that such a peripheral as above might work on some IIGS units and not others?

Ken
www.Apple2Online.com

P.S. If ignorance is truly bliss, why am I not supremely happy???
 
Its doubtful any machine puts out a perfectly stable 15.75khz scanline, thus any piece of equipment is going to have some headroom built into the design. That being said, the Cypress device being advertised has had mixed reviews with how well it works.... or doesn't work. It really is that random. Cypress products look good on paper, but the quality control issues prevent me from actually recommending them.

The GBS-8220 is another cheap upscaler that works for some, but completely fails for others. Its one device that you get what you pay for. Everyone complains about the cheapo units not working right 100% of the time, or lack support of a video mode (like PAL, but this is more of a problem with the Amiga), yet the same problems don't exist on the high end units (ex: Micomsoft XRGB series). This guy has a nice review of various upscalers. For comparison, the Apple IIgs outputs what he refers to "240p" video.

http://retrogaming.hazard-city.de/
 
Is there a reason why something like an old Infocus adapter wouldn't work? I have one at work, funnily enough, we still use it for our daily announcements for the students. Mac mini -> HDFury -> VGA -> InFocus -> closed circuit TV. :D Looks fine to me, and you can make all sorts of manual adjustments like contrast, gain, position (H + V), etc. I think we bought it second hand for $40 at some point.

Edit: HERP DERP! Wrong direction. You're going from IIgs to LCD. :p Nevermind.
 
Drken said:
"These two listings function exactly the same. Important requirement to use this product is the source device must be outputting CGA signal at Horizontal 15.73, or, 15.62 KHz + Vertical 60, or, 50 Hz Non-interlace.
Click to expand...

NTSC color video (the American TV standard) uses a horizontal frequency of 15.734 kHz and a vertical refresh rate of 59.94 Hz.
These were both slightly modified from the original specs used by black & white TV due to the limitations of vacuum tube-based equipment that was in use when color TV was introduced in the 1950s. Black & white TV was originally 15.75 kHz horizontal and exactly 60 Hz vertical. This slight change in frequencies did not affect older B&W TVs because it was still well within normal tolerance.

Therefore whether the IIGS puts out 15.734 kHz video at 59.94 Hz or 15.75 kHz video at 60 Hz, it should not matter to the upscaler. I've seen other manufacturers claim a +/-5% tolerance on the input frequencies, and this is well within that range.
 
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I have one of the linked Ambery scalers. I haven't built an adapter for it for my IIgs. I guess I'll toss it on the to-do list... though it'll be awhile out before I can get to it. I can tell you that the Atari ST crowd at Best Electronics has recommended these devices for use with the Atari ST for years. (my apologies for those of you who click the link - Bruce and his wife are great people to deal with, but he's back in 1995 in regards to his web development habits!!)
 
The GBS-8220 is the unit I currently run on my IIGS. Not sure if the Ambery unit would be a significant improvement or not. I followed all the links given here, and to be honest, became more confused than ever by the time I was finished! Again, my ignorance shines through.... quite brightly, I might add!

What is the relationship between Atari and IIGS video output? And has anyone done a direct comparison of the GBS-8220 & Ambery units? (I apologize up-front if I missed it in the links I followed.) From the original email I received from the Ambery unit vendor on eBay who I contacted, he made it sound like the variation of results - the Apple IIGS will or will not work with it - was the result of production variabilty within Apple, but from what I gather from the comments here, it is more an issue with the quality consistency of the Ambery products. Is that a fair assessment?
 
The video output between the two should be exactly the same, basically progressive RGB with TV scanrates. The exception being the ST's 640x400 monochrome mode, which is VGA like. The Ambery unit seems to have a problem with properly handling 240p according to this thread: http://nfggames.com/forum2/index.php?topic=3315.25 . It interprets the video as 480i and tries to deinterlace it, causing artifacts. Its a common problem with upscalers, so folks tend to seek out the units that DO work properly.

There are a ton of SCART-RGB to HDMI scalers out there now in the area of $50 that would be a better buy with modern LCD monitors, many of which can properly handle 240p video. (see Fudoh's review page above) The adapter often recommended by IIgs users, but now discontinued was the Highway 100 RGB adapter. http://www.converters.tv/products/pal_to_vga/100.html I have no experience with it, so I can't say how well it worked or how good the image quality was.
 
I am sublimely ignorant of such details as Horizontal KHz and interlace vs. non-interlace, but my IIGS uses this $33 converter board to produce this VGA output on an LCD monitor:

GS-VGA01.jpg

I like to tinker, and after considerable trial and error I discovered that the converter worked when the IIGS 15-pin RGB output is connected to the board like this:

Pin #1 to black GND wire
Pin #2 to red R wire
Pin #3 to gray S wire
Pin #5 to green G wire
Pin #9 to blue B wire

As I said on Drken's website, where he first alerted me to this converter, "There's some distortion from the converter output, such as wavy lines on the system 6.01 desktop background and occasional hiccups that bounce the screen image a bit. But it's not too distracting."

Correct me if I'm wrong, Dr. Ken, but I think this is the setup you describe as "acceptable, but still not very good." I agree, and I'm looking forward to something better from the contributors to this thread. But in the meantime, I just wanted to share the details of a $33 converter that actually produces an acceptable display on a VGA monitor.
 
Part of the output problem is the up-scan converter, the other part is the scaler in the LCD. Most of the cheap adapters were never intended to be used with LCDs to begin with. Jim Maricondo ran into the same problems with the XRGB2 on LCD displays (see: http://www.maricondo.org/ ). Based on personal experience, I can say the XRGB2plus in conjunction with a CRT works great, not so much on a LCD. From what I read, the problem has something to do with "dot clocks". The XRGB2 offers an adjustable dot clock that can be tweaked to improve display quality, something the cheapo adapters lack.

The other problem is the LCD's video scaler distorts the video when stretching it to the native resolution of the panel. The best up-scaler will be one that converts the IIgs video to the LCD panel's native resolution and preferably using digital interconnect to eliminate a round of digital-analog-digital conversion.
 
I use an Extron 118 plus, it does EXCELLENT on a CRT display and decent on a LCD, but you do get some artifacts from scaling of LCD since its analog, but I would venture to say it looks a bit better than gib's pic, but still not perfect.

I think the only "perfect" solution for VGA out of a IIgs would be a VGA card, like the "second sight" or possibly the cart blanche card, and I don't know that either are real obtainable, and I would still question their output on an LCD with its scaling (unless you were running 1024x768 mode on a second sight on a 1024x768 LCD panel, that would probably be crisp).
 
vwestlife said:
You could also use an RGB to component video converter, and then use any TV with component video inputs:

http://damntechnology.blogspot.com/2008/08/apple-iigs-rgb-video-to-component.html
Click to expand...

There is a more commonly available adapter called the Cypress CYP-2100. It is a SCART-RGB to component adapter and can be had for $50 on ebay. It is a passive adapter (just does colorspace conversion, no upscanning or scaling) and should work fine on CRTs. Some LCD and Plasmas balk at 240p component video and won't work with it.
 
Hi, I'm new here, but I found this thread while I was researching monitors for my newly-acquired IIgs. I got a Sony 8" production monitor off eBay for $20 that had BNC RGB inputs on it. Using a DB15 to VGA adapter (taken from an Apple 15" Studio Display), a VGA to component cable (from an old projector that died 10 years ago), and a few RCA to BNC adapters, I was able to get the IIgs to display on the sony monitor. I was really surprised it worked. It looked weird at first until I discovered the IIgs was set to 50Hz. Setting it to 60Hz gives me text that looks like this:

iigs_sony.jpg

Thanks for the info above which helped me on my way.
 
Arcady said:
Hi, I'm new here, but I found this thread while I was researching monitors for my newly-acquired IIgs. I got a Sony 8" production monitor off eBay for $20 that had BNC RGB inputs on it. Using a DB15 to VGA adapter (taken from an Apple 15" Studio Display), a VGA to component cable (from an old projector that died 10 years ago), and a few RCA to BNC adapters, I was able to get the IIgs to display on the sony monitor. I was really surprised it worked. It looked weird at first until I discovered the IIgs was set to 50Hz. Setting it to 60Hz gives me text that looks like this:

View attachment 11459

Thanks for the info above which helped me on my way.
Click to expand...

Cool! Welcome to the wonderful world of the Apple II and especially the GS. Glad you were able to gt it to work.
 
Arcady said:
Hi, I'm new here, but I found this thread while I was researching monitors for my newly-acquired IIgs. I got a Sony 8" production monitor off eBay for $20 that had BNC RGB inputs on it. Using a DB15 to VGA adapter (taken from an Apple 15" Studio Display), a VGA to component cable (from an old projector that died 10 years ago), and a few RCA to BNC adapters, I was able to get the IIgs to display on the sony monitor. I was really surprised it worked. It looked weird at first until I discovered the IIgs was set to 50Hz. Setting it to 60Hz gives me text that looks like this:

View attachment 11459

Thanks for the info above which helped me on my way.
Click to expand...

There's a number of CRT monitors, especially broadcast and medical, that will actually sync up with the IIgs very well, I have a 25" NEC (PG-2740) and 2x 20" Sony medical CRTs (used with endoscopes, not sure of model # right now, they are in storage) that sync up really well with it. What the OP was looking for was LCDs that look decent, which is much harder to find, I know there's some for the arcade/amusement/gambling industry that should do well, but they are lots of money, typically in the $1000 range, which is MUCH more than most of us hobbyists want to, or are willing to spend.

I wonder if we should publish some kind of list in the wiki section on what monitors are confirmed working on the IIgs, complete with CRT and LCD displays that folks have tested.
 
Wow, that looks pretty nice. Gotta, ask though, aren't Apple IIGS monitors pretty plentiful and cheap. Actually, whole systems usually sell for $100-200 on ebay, some with free shipping. Just buy the bundle and sell the extra system :)
 
datajerk said:
What is the Sony monitor model number? Thanks.
Click to expand...

It is a Sony PVM-8044Q. The same seller also has some 13" and 14" models and I might pick up one of those now that I know this works.

RWallmow said:
What the OP was looking for was LCDs that look decent, which is much harder to find, I know there's some for the arcade/amusement/gambling industry that should do well, but they are lots of money, typically in the $1000 range, which is MUCH more than most of us hobbyists want to, or are willing to spend.
Click to expand...

I know the intent of this thread was to find an LCD solution. In fact that's why I ended up looking at this thread in the first place. I was trying to get my Apple Studio 15" to work with the IIgs, using its built-in composite input, but it will not work with the IIgs or a //e. The talk about using RGB converters is what made me think it should work with the RGB inputs on a fairly recent production monitor. The monitor I bought for $20 was like $800 originally. Oh, and the plus to using this monitor is it has multiiple inputs, so I can also connect a //e and even things with s-video like a DVD player, etc.

I also have a 17" Samsung LCD TV that has a SCART input. I'm going to look into getting an RGB to SCART adapter for that, but the downside is it is a 16x10 ( 1280x768 ) panel.
 
Arcady said:
I also have a 17" Samsung LCD TV that has a SCART input. I'm going to look into getting an RGB to SCART adapter for that, but the downside is it is a 16x10 ( 1280x768 ) panel.
Click to expand...

I have heard stories of the IIgs working well on SCART displays, however here in the US finding a SCART capable monitor/TV is like finding Atlantis, so I have had no experience with that. If you live in a country where SCART is common, it might be a lot easier to get a decently working LCD on a IIgs.
 
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