Apple IIGS screen size



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Author	Apple IIGS screen size (Read 82352 times)
ShinobiKenobi 256 MB Posts: 362 System 7 fan	on: July 08, 2025, 21:16 I have an Apple IIGS and have GS/OS. But it's always a square screen. But I found a webpage here (modern browser) that shows one with GS/OS maximized for the entire monitor size. How do you do that? Was it a special version of the OS? I'd like to get more screen space

cballero 1024 MB Posts: 1176 System 7, today and forever	Reply #1 on: July 08, 2025, 21:24 So you want more green space without sending more green? sorry, I could resist slipping in a little joke there! but it'd be sweet if you do figure out how they pulled that off!

lauland 512 MB Posts: 674 Symtes 7 Mewconer!	Reply #2 on: July 09, 2025, 15:51 I've got a IIgs and have fiddled quite a bit with the video so can probably answer you. First off some background... The IIgs doesn't output ANYTHING like what any modern monitor can handle directly, unless it has special support. It has two outputs, one is NTSC video (the round RCA plug), which has truly minuscule bandwidth, but is very simple to process, if you have the hardware to handle it. The output is extremely fuzzy, and 80 columns aren't likely readable without a B&W monitor. The other is the flat "D" plug which is analog RGB, but it only at 15 khz, and VGA monitors typically never go lower than 30 khz. So you'll need a "scandoubler" or something like that. If you have a good converter, you can use a modern monitor and get a decent signal this way. This is what I do. The third option, is using a monitor actually designed for the beast, of course. This will be fuzzier than modern monitor, but probably look the best since it was designed for it. ---- If you're seeing a "square screen", getting it to take up more of the monitor will depend on which signal you're using, how you're converting it (if you're using a mondern monitor), and what your monitor can handle. Let me know more about your monitor and how you connect the IIgs to it and we'll see if we can figure out if there are settings you might be able to adjust SOMEWHERE. Chances are there isn't a software fix, as the IIgs isn't terribly flexible with its video hardware, and can only output IIe compatible and 320x200 or 640x200 modes. The border you're seeing around the picture is probably an artifact of your monitor or converter.

ShinobiKenobi 256 MB Posts: 362 System 7 fan	Reply #3 on: July 10, 2025, 02:06 @cballero Yes! I emailed him, but I haven't got an answer yet. Maybe I need an upgrade of some sort. @lauland I'm using the AppleColor RGB Monitor that it came with.

lauland 512 MB Posts: 674 Symtes 7 Mewconer!	Reply #4 on: July 10, 2025, 15:58 Oh dang, I was hoping that wasn't the one you were using, because that is (one would hope) designed for it, so functioning as designed. Unless its having problems? The short answer as to how he did it, and how I do it, is we use a modern monitor with a scan doubler. If you watch the video closely you might be able to see the brand of the monitor, or at least if it looks like an apple model or not. My guess is that is what he did, and any IIgs owners not using original monitors. The scan doubler is needed because the IIgs only outputs a 15khz 200 pixel tall signal, and the lowest any modern monitor will go to is 30khz 400 pixels. So it sits between the machine and the monitor and upgrades the signal to VGA quality. My scan doubler isn't the best there is, so it isn't as clear as can be, but is pretty good. Now, I'm not saying there ISN'T possibly a software solution, but not likely. Now, I googled your monitor and I see a lot of pictures of it that seem to show the display taking up "the whole screen". Is it possible your monitor might be having problems? Are you seeing a too large border around the image or is it shrunk? Huh...I just googled "apple iigs scan doubler vga output" (to show you what it looks like) and I see tons of pictures of displays with HUGE borders, and the picture shrunk down in the middle. Weird. Maybe "it depends" on what hardware you are using. Anyway this page shows a lot of options, info, and links: https://www.apple2faq.com/apple2faq/apple-iigs-modern-video-options/ (modern browser) Personally, I use a GGlabs GS2HD to get the separate RGB component outputs, and run those through a converter that looks almost identical to the Gonbes GBS-8220 shown on that page. It takes almost any sort of video and buffers it to make a 640x480/800x600/1024x768 display (obviously interperlating the retro pixels, hence not sharp). I use the same converter for my Amiga. Its not perfect for either, but good enough for 25+ year old hardware.
Last Edit: July 10, 2025, 16:04 by lauland
Cashed 128 MB Posts: 192 System 7 Newcomer!	Reply #5 on: July 10, 2025, 16:58 Hi ShinobiKenobi. I’m unfamiliar with the IIgs -these links may or may not be of use. from the little I caught, it seems like you have so set the screen mode in the application -I may be mistaken) Search (Set screen mode) link shortned Search (Size) link shortned Search (Set display area primary) link shortned Using the IIgs monitor link shortned DisplayModeTester.2mg link shortned Search (Display) & (Screen aspect) link shortned Update: Display settings located in the control panel at startup. There’s also the A2FPGA
Last Edit: July 10, 2025, 20:49 by Cashed
lauland 512 MB Posts: 674 Symtes 7 Mewconer!	Reply #6 on: July 10, 2025, 22:22 Just FYI, the first four links are about the machine language monitor, which is the Apple 2 equivalent of our beloved Macsbug on Macs, basically a debugger, but on the Apple 2 also used in the distant past to actually write some software. Unless you are a programmer, you'll remain blissful if you never touch it. The 2mg disk image might be useful... The one about aspect is about converting images to and from apple 2 formats. Now, the final one, the A2FPGA is really cool. It would let your Apple output a modern HDMI video signal and so probably would solve all your problems. If you have that, you don't need a scan doubler or converter at all, and could plug your apple into almost any modern display. I'd love to buy one of these, but can't justify my wallet.

ShinobiKenobi 256 MB Posts: 362 System 7 fan	Reply #7 on: July 11, 2025, 01:31 @lauland I'm not sure what video you're talking about. In the page I linked to, there are two pictures that show the IIGS screen with the AppleColor RGB Monitor that use the whole screen. I went to double check mine, and I can adjust the height, but not the width. This is about the best I can get the picture, which looks a little stretched vertically, but not bad. But I can't adjust the width. @Cashed Thanks for those awesome links. I agree lauland, the adapter looks really awesome.
Last Edit: July 11, 2025, 02:20 by ShinobiKenobi
Cashed 128 MB Posts: 192 System 7 Newcomer!	Reply #8 on: July 11, 2025, 01:44 Thanks for the enlightenment @lauland, as you already know -I always love to learn. I vividly remember your posts in the Arashi Black & White, and the Which Game? thread -I learned so much! Yea, it relies on the display modes and the resolution of the software being run. I thought, (to myself -but ended up posting my thoughts), that using a disassembler one could change the display area, like the assembler editor Merlin runs in full screen mode. But the software is programmed to do that. @ShinobiKenobi, that's not bad at all -that looks great! It could be bad connection if your width control does nothing at all. PS, You're welcome -thanks for challenging me to learn more retro tech
Last Edit: July 11, 2025, 01:46 by Cashed
lauland 512 MB Posts: 674 Symtes 7 Mewconer!	Reply #9 on: July 11, 2025, 04:06 Oh! Ok...I didn't pay enough attention, if he's using the exact model you are AND it is taking up the full frame (aka screen) then something else is up...and pretty much everything I've said is probably pointless. (ie you just want to use the monitor you've got, and scan doubling, although interesting, isn't in the picture). Does your monitor have a width adjustment? If so, and it doesn't help and/or work, then @Cashed's idea the connection for that might be bad is a good one. On the other hand, old analog monitors can develop problems, and the beam may no longer be able to go all the way to the edges, or there might be some sort of internal tweak or adjustment you'd need to do...you may want to search specifically for that. I think the "flyback" is for the vertical, not horizontal, but searching for that sort of thing may help. Goes without saying, if you end up having to crack the monitor open, be super careful with the high voltages. If there's no OBVIOUS adjuster for width, look for screwholes where you might be able to poke a screwdriver in. Some monitors have those. It's possible the guy in the video did that.

MTT 256 MB Posts: 394 SSW7 Oldtimer	Reply #10 on: July 11, 2025, 05:06 Quote from: ShinobiKenobi: "found a webpage here (modern browser) that shows one with GS/OS maximized for the entire monitor size. How do you do that?" That picture linked in your first post, is what I would call "a mock-up". Where a stock photo of a IIGS was used and the desktop in the pic added later, stretched to appear to fill the screen. I think the screenshot of the desktop by itself (3rd pic down) in that page is the more accurate representation of a IIGS 640x200 desktop display. View this pic of your IIGS, and you'll know it's not real. I copied your desktop picture, and stretched the display area in Photoshop. I think this is the equivalent to what someone had done with that picture linked in your first post. A more honest representation of a IIGS desktop is shown in this page, top picture and 5th picture down. Which show an accurate 640x200 IIGS desktop in each pic, in the monitor screen. The reason why you can't stretch the display to fit the width of the screen of an AppleColor RGB Monitor, is that the 3 adjustment knobs at the rear of the display unit allow only vertical stretch/shrink, not horizontal stretching. The two outer knobs are to stop the display from panning up/down or left/right. What you have set (as shown in your actual pic) according to point 5 in this screenshot from the monitor's Owner's Guide, seems pretty much what Apple recommended that you should do.
Last Edit: July 11, 2025, 05:24 by MTT
ShinobiKenobi 256 MB Posts: 362 System 7 fan	Reply #11 on: July 11, 2025, 07:58 Alright, thanks guys. I guess that's the best I can get. I wonder why Apple frequently had monitors that didn't use the entire screen.

wove 1024 MB Posts: 1363	Reply #12 on: July 11, 2025, 14:12 I believe there actually is a horizontal width adjustment on that monitor, but it is located inside the case. If you remove the back case in the area where the outside adjustment knobs are located you will find some adjustable ferrite coils. These coils are adjustable with a plastic hex wrench. You do not want to use a metal "allen wrench" since they may break the coil and the metal of the wrench affects the performance of the coil. (Apple's Service repair manual shows a more precise location.) Move the ferret plug in the coil will change the width of the screens display area. Typically CRT monitors' image reduces in size as the monitor ages. Generally only one of the width/height controls are presented to the consumer, since it is expected they will only be used to change the screens geometry. Are squares square, are circles round and for that you only need to use one of the adjustments. If I remember correct my SE/30 picked up the same problem of the screen width getting narrower over time, and the width adjustment is hidden in side. Of course all the usual caveats of working on CDTs apply, so user discretion is required.

lauland 512 MB Posts: 674 Symtes 7 Mewconer!	Reply #13 on: July 11, 2025, 20:30 Yeah, I had a Classic II, sadly now at least temporarily defunkt due to bad caps, that I did the same thing to, now that I think of it.

ShinobiKenobi 256 MB Posts: 362 System 7 fan	Reply #14 on: July 11, 2025, 21:31 Cool, thanks wove If I need to take it apart, I might put up with this for a while. It's not terrible the way it is now. Sorry to hear that, lauland. What tool is recommended for adjusting those? Also, nice Photoshop skills MTT!
Last Edit: July 11, 2025, 21:36 by ShinobiKenobi
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