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Hercules graphics card question

Trixter said:
No, it honestly doesn't, for at least two reasons: 1. 200 lines does not map cleanly into 480 (some lines double),
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I don't think it would use 480 lines to render a 200-line mode, though. I think it would switch to the 400-line timings used for the text modes.
 
Trixter said:
Actually, it is possible, but only from system memory to system memory, and only using DMA channels 0 and 1. You have to copy at least 256 bytes since it is your copy that is refreshing the memory and 256 is the minimum needed to keep it alive. Some motherboard arrangements also require you to read from every bank or other irritation. A shame, since it would have been cool to get faster copies than the CPU is capable of.
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And that requirement for interfering with refresh makes it useless for most applications. Too bad. Even using DMA memory-to-memory transfer to access physical memory above 1M would have been wonderful on a 286.

No, it honestly doesn't, for at least two reasons: 1. 200 lines does not map cleanly into 480 (some lines double), and 2. the 320x200 graphics were usually composed specifically for that mode and output device. Any color/brightness choices had the 200-line display in mind.
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All lines double when you're mapping 200 to 480, if my arithmetic isn't wrong. You can take the remaining 40 lines and distribute them as black space at the top and bottom. The slight distortion in aspect ratio isn't a huge problem.

I submit you never had a decent CGA monitor :-) The 5153 is pretty good. The PCjr monitor is terrible (color and brightness are great but the dot pitch is so bad that everything looks fuzzy). My first CGA was actually the 25Khz 400-line AT&T 6300 monitor, so I was spoiled rotten. I currently code on a 5153 and I'm very happy with it.
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I bought the best monitor that I could find when I decided to give color a try--a Sony CPD1302. Is that good enough? I liked it so much after buying a Mitsubishi DiamondScan, that I bought another Sony.

When I went to EGA, I finagled a deal on a Daisy Systems fixed-frequency 20" monitor (Mitsubishi under the very heavy case, I think). I was unimpressed with most of the PC-targeted crop of monitors.

But until EGA came out, I was disgusted with the lousy quality display available on ANY CGA monitor setup. It reminded me of the home video games of the time.

Even the text mode is terrible when compared with the Hercules mono setup.

In a way I can understand the poor display quality of a CGA. After all, one promoted application was to drive an RF modulator hooked to your TV set. If I wanted video-game graphics, I would have bought a C64 and saved my money.
 
Lots of information, but no conclusion what is the best CGA.Emulator for a Hercules-Card.

HGCIBM = is in my opinion VERY slow
UCGA = with the flag /f is good, but displays an interlaced image
SIMCGA = full image-quality but poor image-quality on moving objekts
EMU = superbe image-quality and very good performance but not usable on my MM12 monitor, on the multiscan it is OK (scali mentioned that it's tweaking to 60hz and my MM12 does only 50hz)
EMU0 = interlace but fast (has some vertical-lines on my euroPC with MM12) does not know where they come from

Is there something better out there?

Greetings
Doc
 
Chuck(G) said:
All lines double when you're mapping 200 to 480, if my arithmetic isn't wrong. You can take the remaining 40 lines and distribute them as black space at the top and bottom. The slight distortion in aspect ratio isn't a huge problem.



I bought the best monitor that I could find when I decided to give color a try--a Sony CPD1302. Is that good enough? I liked it so much after buying a Mitsubishi DiamondScan, that I bought another Sony.

When I went to EGA, I finagled a deal on a Daisy Systems fixed-frequency 20" monitor (Mitsubishi under the very heavy case, I think). I was unimpressed with most of the PC-targeted crop of monitors.

But until EGA came out, I was disgusted with the lousy quality display available on ANY CGA monitor setup. It reminded me of the home video games of the time.

Even the text mode is terrible when compared with the Hercules mono setup.

In a way I can understand the poor display quality of a CGA. After all, one promoted application was to drive an RF modulator hooked to your TV set. If I wanted video-game graphics, I would have bought a C64 and saved my money.
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I do not believe that a comparison between CGA video quality and video game consoles is a very apt one. CGA connected through digital RGBI, perhaps the cleanest signal then in existence. All pre-crash consoles connect through an RF connector, the worst possible video connection available, and it seems to be the default method for the rest of the 1980s consoles. Even the C64 could only do separated video (S-video more or less) at best.

While IBM CGA its snow issue and MDA text is nicer to look at, I would suggest that the MDA monitor's ghosting is a worse issue. This is especially true when it comes to animation. Also, the actual MDA display shows a rather rectangular active display, and shoehorning 320x200 graphics into 720x348 leaves even less display space (320 to 640 pixels) or introduces stretching artifacts (200 to 300 lines).

Sierra's Hercules driver for its SCI0 games show very unsightly text as a result. Similarly when its SCI1.1 games use the SVGA driver, the 200-line backgrounds are stretched to 480 lines, showing similar stretching issues.
 
dr.zeissler said:
Lots of information, but no conclusion what is the best CGA.Emulator for a Hercules-Card.

HGCIBM = is in my opinion VERY slow
UCGA = with the flag /f is good, but displays an interlaced image
SIMCGA = full image-quality but poor image-quality on moving objekts
EMU = superbe image-quality and very good performance but not usable on my MM12 monitor, on the multiscan it is OK (scali mentioned that it's tweaking to 60hz and my MM12 does only 50hz)
EMU0 = interlace but fast (has some vertical-lines on my euroPC with MM12) does not know where they come from

Is there something better out there?

Greetings
Doc
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Based on this summary, I am still rooting for SIMCGA. Interlacing is not a good thing to view when your face is less than two feet from the screen. Running an MDA monitor at 60Hz is a good way to ruin it.
 
Great Hierophant said:
I do not believe that a comparison between CGA video quality and video game consoles is a very apt one. CGA connected through digital RGBI, perhaps the cleanest signal then in existence. All pre-crash consoles connect through an RF connector, the worst possible video connection available, and it seems to be the default method for the rest of the 1980s consoles. Even the C64 could only do separated video (S-video more or less) at best.

While IBM CGA its snow issue and MDA text is nicer to look at, I would suggest that the MDA monitor's ghosting is a worse issue. This is especially true when it comes to animation. Also, the actual MDA display shows a rather rectangular active display, and shoehorning 320x200 graphics into 720x348 leaves even less display space (320 to 640 pixels) or introduces stretching artifacts (200 to 300 lines).

Sierra's Hercules driver for its SCI0 games show very unsightly text as a result. Similarly when its SCI1.1 games use the SVGA driver, the 200-line backgrounds are stretched to 480 lines, showing similar stretching issues.
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A better alternative is the AT&T/Olivetti 6300/M24 640x400--of course, this required a different monitor, closer to a EGA.

As far as the IBM 5151 monitor goes, I never used it. A lot of my work was done with a 17" OEM monitor with a shorter-persistence jug. Ghosting was no problem. There were plenty of third-party monitors that didn't display the ghosting problem either. Since the MDA/Herc didn't have the "snow" problems of the CGA, it was also a faster display.
 
Have you looked at the moving objekts while using simcga ?
they are really "fuzzy". Testdrive1 and Gprix animations look really bad on my machine.
I do not use the internal "cga-emulation" of the game, I start the seperate cga-emulation and und directly "gpcga", or "tdcga".
The internal CGA-Emulators of the game are similar like "ucga /f" option.

I currently searching for "emu" with no 60hz. http://www.sorgonet.com/8086/CGA_emulation/
 

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Trixter said:
One of these days I'm going to finish my tweaked CGA graphics viewer. 40+ colors at a resolution of 80x100 already works on RGB
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!!

:wow:

(How?)

As for the Herc higher rez dispute, I don't think there should be an argument, because de gustibus non est disputandum. Save for a doubled line here and there, the information content of x coloured CGA pixels and x * n monochrome Herc pixels is identical as we all know. Of course the way that information content results in the display of a few mono pixels for each colour pixel amounts to a "kinda, sorta" simple type of dithering, and of course the number of Herc pixels displayed is higher there (x * n > x). Some might find the higher Herc pixel count more pleasing to their eyes with some software. Some might find the fewer colour pixels more pleasing with certain programs. De gustibus non est disputandum.
 
Chuck(G) said:
As far as the IBM 5151 monitor goes ... There were plenty of third-party monitors that didn't display the ghosting problem either.
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Many people didn't deem that high-persistence green phosphorus a problem or bug at all, but rather saw it as a feature, because it reduced flicker and thus eyestrain -- if you were using software where the screen content rarely changed. Better for work than for games, generally speaking.
 
Chuck(G) said:
As an example of something similar many late NTSC TVs "de-interlace" the video signal and display each non-interlaced frame twice. The claim is made for better resolution, even though neither the frame rate nor the bandwidth has changed.
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If your TV is displaying duplicate frames on NTSC material (not converted from 24fps film) then it is either broken or improperly designed. Modern flat panel TVs should be able to de-interlace NTSC video's 60 interlaced fields per second into 60 frames per second, resulting in full 60fps motion, not frame-doubled 30fps.

An example of NTSC video converted to 60fps (if your web browser supports it):

 
dr.zeissler said:
Have you looked at the moving objekts while using simcga ?
they are really "fuzzy". Testdrive1 and Gprix animations look really bad on my machine.
I do not use the internal "cga-emulation" of the game, I start the seperate cga-emulation and und directly "gpcga", or "tdcga".
The internal CGA-Emulators of the game are similar like "ucga /f" option.
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Who do you think wrote SIMCGA? :)

It was intended as nothing more than a stopgap to allow programs written for color graphics only to run on Herc-equipped machines, which, at the time was pretty much the low-cost Taiwanese import standard. Color monitors were significantly more expensive than monochrome and remained so for quite some time.

Try running, oh, say, Flight Simulator in native Hercules mode and the situation is much different.
 
Chuck(G) said:
Who do you think wrote SIMCGA? :)
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It's impressive at how wide spread it is. I often find it inside game folders over here in NZ - more so than any of the others mentioned. Testing a portable in the weekend and found it again, I was like "yey Chuck!".
 
The ATI Small Wonder has very impressive hardware CGA -> Hercules and Hercules -> CGA emulation. On an MDA/Hercules display, it simulates different shades of gray (or green, etc.) by flickering the pixels at different rates. And it uses interlaced mode to display MDA/Hercules at its full resolution on a CGA or composite display.
 
I didn't get a chance to get any footage of the ATI Small Wonder emulating CGA on Hercules before I sold the computer containing it (a Packard Bell PB 500) to a fellow VCF member, but I did get some screenshots of it emulating MDA/Hercules on a CGA monitor (a Tandy CM-11):

MDA-emulated2..jpg

Hercules-emulate&#10.jpg

MDA-emulated1..jpg
 
I have an ATi Small Wonder in one of my PCs. I could show something sometime.
Another one of my PCs has a Paradise PVC4, which can do exactly the same thing.
 
In my opinion. Hercules native looks way better then CGA (4colors). Tandy-CGA with 16 colors is the same as EGA in Lowres.
Emulated CGA on Hercules is a bit of a problem. Without scanlines it look great but has very poor performance and quality of moving objekts while using a XT.
With scanlines it is fast and has no ghosting/fuzzeling effects.

"EMU" has no scanlines and is very fast. Is it true that this is because of the tweaking to 60hz instead of 50hz?
Or can "EMU0" be tweaked to run without scanlines ?

Thx
Doc
 
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