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First boot of a new IIgs - help!
- Thread starter bigmessowires
- Start date
Or, for most of what Apple II Pi does you could just transfer your physical Apple II disks into images using ADTPro and run them on the same GSport emulator it uses for its Apple ][ environment on whatever laptop you have lying around and end up with a mostly superior user experience.
(Guess it sort of shows I don't really get the appeal. Sort of the point of having physical "retro-computers" lying around to play with is "authenticity", but when you're running Apple II software via A2Pi the only part of your Apple you're using is the keyboard, the rest is just as fake as if you were running it on your Windows 8 gamer-boy tower. Might as well save the wear and tear on your Apple II and just use a regular keyboard; as a bonus other software like web browsers will be running *way* faster than they do on a Raspberry Pi.)
(Guess it sort of shows I don't really get the appeal. Sort of the point of having physical "retro-computers" lying around to play with is "authenticity", but when you're running Apple II software via A2Pi the only part of your Apple you're using is the keyboard, the rest is just as fake as if you were running it on your Windows 8 gamer-boy tower. Might as well save the wear and tear on your Apple II and just use a regular keyboard; as a bonus other software like web browsers will be running *way* faster than they do on a Raspberry Pi.)
On the topic of IIgs RGB video output - does anyone know if it's the same as CGA video, found on old PC graphics cards? CGA is also described as a 15 kHz video signal with analog RGB. Maybe the sync is different? If it is the same, then it looks like you can buy CGA to VGA adapters that will do the job. http://www.arcadeshop.de/Audio-Video-Converter-CGA-to-VGA_778.html?osCsid=9pi5d808g4q2hbgoen7n1vaiq5
Yes, that unit will work, but the quality is likely "eh", "meh", or non-existent. The GBS-8220 board that likely came out of the same factory in China is commonly found for $30 or so and works on the IIgs. Quality control is non-existent, so what you get might not even work. Video scalers is one area that you get what you pay for. There is a good chance that the scaler in your monitor is of much better quality.
Perhpaps its scaler is better, but my monitor won't accept 15 kHz RGB, so it can only use composite video. I'm guessing 15 kHz RGB converted to VGA with one of these CGA adapters would look a lot better than that, even if it were still short of what a real CRT would look like.
A commenter on my blog also pointed out this homebrew adapter based on an Altera DE0-Nano. It's got a very nicely detailed write-up of how it works. https://sites.google.com/site/tandycocoloco/rgb2vga
A commenter on my blog also pointed out this homebrew adapter based on an Altera DE0-Nano. It's got a very nicely detailed write-up of how it works. https://sites.google.com/site/tandycocoloco/rgb2vga
I mentioned earlier in the thread that I've been using one of those "CGA to VGA" boards on my IIgs setup. (And I'm forced to be pedantic here: those boards *are not actually "CGA"; CGA is digital RGBI, not analog, and while those boards are tolerant of digital input they don't actually display CGA correctly without some external help because they don't have a separate "intensity" input. They are in fact more directly aimed at things like the IIgs, CoCo III, arcade boards, etc, which produce NTSC-rate RGB *analog* output... but I suppose that's neither here nor there for the moment.)
Anyway, the board I have is a definite improvement over the composite output, but as I said earlier it's not perfect, at least when paired with the LCD monitor I happen to have handy. In short, the issue is this: Remember back in the old days 8 and 16 bit computers would let you set the color for the border/overscan area of the screen? (On an old CRT that of course is a semi-significant percentage of the visible glass area of the monitor.) For authenticity (I guess) those scalers render the border area in their output, and what that ends up translating to is on, say, a 1280 pixel wide LCD display about a quarter of the pixels will be rendered in the border leaving 960 physical pixels for the 640 pixel wide high-res desktop output from the IIgs to be spread across. Obviously that means a non-integer scaling factor needs to be applied for that, and in the end the result is that certain things like the default pinstripe desktop in GS OS still look sort of bad.
In all fairness things like games look pretty darn good. The desktop *might* look better if you used a VGA CRT (granted that's sort of missing the point) or, perhaps, a higher-res monitor that could scale the output better? Those things really are more meant for games than "productivity applications" so I can't really fault it that much.
Anyway, the board I have is a definite improvement over the composite output, but as I said earlier it's not perfect, at least when paired with the LCD monitor I happen to have handy. In short, the issue is this: Remember back in the old days 8 and 16 bit computers would let you set the color for the border/overscan area of the screen? (On an old CRT that of course is a semi-significant percentage of the visible glass area of the monitor.) For authenticity (I guess) those scalers render the border area in their output, and what that ends up translating to is on, say, a 1280 pixel wide LCD display about a quarter of the pixels will be rendered in the border leaving 960 physical pixels for the 640 pixel wide high-res desktop output from the IIgs to be spread across. Obviously that means a non-integer scaling factor needs to be applied for that, and in the end the result is that certain things like the default pinstripe desktop in GS OS still look sort of bad.
In all fairness things like games look pretty darn good. The desktop *might* look better if you used a VGA CRT (granted that's sort of missing the point) or, perhaps, a higher-res monitor that could scale the output better? Those things really are more meant for games than "productivity applications" so I can't really fault it that much.
Ah, that makes perfect sense now. Thanks for explaining. Yeah, I can imagine pinstripe and checkerboard patterns would look pretty bad under those conditions. In a perfect world, there would be a switch on the adapter to select whether to display the overscan area. Maybe I'll try to design such a thing for a future project, if it doesn't already exist. It has a lot in common with the "video out for compact Macs" idea that I've been kicking around for a while.
I really like that adapter. If you decide to make any, BMOW, let me know. I'd love to buy one or two. Replacing an aging CRT with an LCD for my Apple IIs would be pretty handy. I've yet to have a good conversion yet that doesn't cost more than the computer.
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The biggest problem with these "simple" scan-doublers is that they don't seem to work with LCDs properly. People ran into problems with older Amiga "flicker fixers" and the higher end Micomsoft XRGB2plus (the problem was bad enough that the manufacturer maintained a list of compatible LCDs on their site) . LCDs are picky about signal and sync timing as you found out, and many of these devices don't put out a VESA or VGA compliant signal, they simply line double an out of spec signal. See: https://web.archive.org/web/20141217134748/http://maricondo.org/
That is why the latest generation of scan doublers are full blown scalers with HDMI/DVI output. Also, if you are going to digitize the signal, you might as well scale it to the native resolution of the panel you are using and avoiding needless analog-to-digital-to-analog-digital conversions.
Oh, and if you want to read about scalers, the IIgs outputs 240p video for reference: http://retrogaming.hazard-city.de/
It can also be booted from a CFFA3000 card if you happen to have one handy! I also did the HDD SCSI disk install on mine. A bit of a challenge...
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