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Hercules graphics card question

Xacalite said:
You mean you can't set mode 7 on a genuine IBM VGA? Works fine with all (almost all?) VGA clones.
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The mode might work, but afaik it is not MDA-compatible. As in, it won't be register-compatible with the 3Bxh range of 6845 registers (much like you can set CGA modes on EGA/VGA as well, but you aren't register-compatible with CGA, so things like setting palette or setting tweak-modes won't work as expected).
And it most certainly does not support Hercules graphics either.

Xacalite said:
BTW, while we're at Hercules and demos: ever seen a demo for HGC graphics mode? Back in the era I heard some rumors about one, but never found it...
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Nope, never seen any.

Xacalite said:
But there's still a problem with Hercules: some software uses the second video page which conflicts with CGA.
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Well, CGA also conflicts with EGA/VGA, since they are not 100% register-compatible (which is why afaik there is no EGA/VGA card out there that has a 100% working CGA compatibility mode. Real EGA/VGA have no such thing at all, and on the ones I tried which have a tool to switch it to CGA mode, the timing was all over the place. It's better than nothing, but it mainly just emulated the proper CGA font and the CGA palettes, no more than that. Funny how so many people only know CGA-on-VGA, with the default cyan/magenta palette... many screenshots of games on the web too, in this mode, rather than with the proper palette).
So as a user you need to specify which specific card or cards you want to emulate.
Then the emulator needs to behave the same way. So yes, if you choose Hercules + CGA/EGA/VGA, you lose the second video page on Hercules. This is by design.
And if you choose EGA or VGA, you don't get 100% CGA compatibility (and no composite option).

So, I think it should look as follows:
You get to select two cards, one mono and one colour.
For mono you can choose none, MDA or Hercules.
For colour you can choose none, CGA, EGA, VGA or SVGA.

Mono will get an output window, and colour will get an output window.
When you use CGA, the emulator could either allow you to switch between RGBI and composite emulation, or it could create two separate windows.
I personally don't think it's very useful to emulate two windows, because they always display the same image, just in a different mode. You generally just want to view the image in the appropriate mode, rather than viewing both side-by-side (although this could be interesting as a debug-option perhaps).
 
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FWIW, at least some VGA cards can also coexist with CGA, but only if the VGA card is restricted to monochrome modes (mode 7 text, and possibly Hercules graphics emulation).
 
Scali said:
BTW, while we're at Hercules and demos: ever seen a demo for HGC graphics mode? Back in the era I heard some rumors about one, but never found it...
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Nope, never seen any.
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I can't believe nobody ever made anything for such an ubiquitous hardware...
However, if it's true, then there's still a chance to do something very special: first Hercules demo ever!
Hint, hint ;)
 
Xacalite said:
I can't believe nobody ever made anything for such an ubiquitous hardware...
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There aren't a lot of games that have native Hercules support either.
Most of them use CGA emulation.
I think the main reason is that the native resolution is very high. If you want to do some kind of action game, that's a lot of pixels to update.
So it's probably faster anyway to just do 'lowres' CGA animation, and then convert the image to a Hercules tweakmode.

Xacalite said:
However, if it's true, then there's still a chance to do something very special: first Hercules demo ever!
Hint, hint ;)
Click to expand...

Yes, not a lot of room for effects though. You don't have a palette, and you can only enable or disable individual pixels.
You could do some 6845-tweaking, but that's about it, I guess.
 
Scali said:
There aren't a lot of games that have native Hercules support either.
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True, I only know two games using 720x348 mode with good results: Blockout and Spacewar.

I think the main reason is that the native resolution is very high. If you want to do some kind of action game, that's a lot of pixels to update.
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For an 8088@4.77Mhz, definitely.
However, Hercules cards were common (around here, at least) in 286 clones as well, so I would consider 286 as a reasonable requirement.

You could do some 6845-tweaking, but that's about it, I guess.
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There's a few interesting modes in addition to the default 720x348:
- 640x200 - commonly used by CGA emulators
- 640x300 - same as above
- 720x360 - ever wondered why Hercules displays 720x350 in text mode, but only 720x348 in graphical? Vertical resolution must be a multiply of four, so the next step would be 720x352, and I guess the designers opted to stay on the safe side. But yes, it can display even a little more than 720x350.
- 640x400 ie. 640x200 with interlace - in theory good for emulating 320x200x16, unfortunately fails to work on many cards, including Hercules Graphics Card Plus. Also, interlace = useless for anything serious.
 
How can I check what (emulated) resolution the Game works with under MDA/HGC ?
Do you think the available "cga-emulators" are state of the art, even today because they are mostly from the mid/late 80s, perhaps there is (much?) room for optimisation?

For me, it's a difficult thing to choose what machine for retro-gaming.
T1000 native titles are 16c and there is no better option, but the cga 4c-stuff is better played with a MDA/HGC card and emulation, because the palettes are VERY AWFULL.
Mostly they look much better under MDA/HGC in CGA-Emulation mode.

Perhaps a "4color-mono"CGA is the best option, but I don't have that. The better/sharper image-quality under hercules is my favorit.
 
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MM12 stands for Monochrome Monitor, 12"
CM14 stands for Color Monitor, 14"

Afaik, it has nothing to do with Hercules, CGA, or whatsoever. The MM12 can display EGA as well, so I don't see why it shouldn't do CGA.
 
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I do not get it yet. The EuroPC has CGA or MDA. You think I could switch to CGA but use the MM12 with it?
I thought the machine beeps and stops with a configuration error?
 
I don't own a EuroPC, so I can't answer that question. I don't see why it would beep, however, as there was no monitor type detection back then.
 
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I believe the EuroPC has a Paradise PVC4... which I believe you can configure to work in CGA-compatible mode on an MDA monitor.
It should have some jumpers or dipswitches for that.
My Commodore PC20-III has them anyway, seem to be the same as an ATi Small Wonder.
See page 2-3: http://dostalgie.de/downloads/pc10III-20III/PC10III_OM_COMMODORE_EN_DE.pdf
You select the mode separately from the monitor, see switches 2, 3 and 4.
 
dr.zeissler said:
How can I check what (emulated) resolution the Game works with under MDA/HGC ?
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With a little experience it's clearly visible: native Hercules mode (720x348) occupies (nearly) entire area of the screen, 640x300 leaves some empty space, 640x200 leaves more empty space.

Do you think the available "cga-emulators" are state of the art, even today because they are mostly from the mid/late 80s, perhaps there is (much?) room for optimisation?
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No room for optimization here, not with 8088/286 anyway.
In theory, with a fast enough CPU and ability to trap I/O instructions (ie. 386+) it would be possible to create a better emulator, supporting eg. CGA's 160x100 mode, but 386+ machines with Hercules were rare.

I don't know about Schneider MM12, but there was plenty of mono monitors capable of working with both MDA/Hercules and CGA frequencies.
 
A little question (maybe a little OT)... did anybody test this kind of equipement (there are a lot on eBay) ?

http://www.ebay.it/itm/CGA-EGA-YuA-...095966?hash=item5b0f71201e:g:KR0AAOSwEppUTjPS

Quite hard to find a CGA monitor today... maybe this kind of converter can help a bit...

Disclaimer ;-) : I agree this is not a vintage, "pure" solution... but at least it could help if you haven't a color CGA monitor - like me. I have a 5160 with green CGA monitor and an XT japanese clone with a B/W MDA monitor... but the clone has two graphic cards inside, an MDA (or Hercules, I didn't discover it yet) and a CGA. I'm using the MDA but I wish to see the CGA working...

BTW I also have an ISA, 8/16 bit (jumper selecting) VGA that doesn't work in both XTs (5160 and clone), even setting correclty the MoBo switches. The 5160 refuses to start (beeeeeep) while the clone starts (beep) but no output from the VGA card (I tested the card into another PC and it works fine). Any idea?
 
giobbi said:
BTW I also have an ISA, 8/16 bit (jumper selecting) VGA that doesn't work in both XTs (5160 and clone), even setting correclty the MoBo switches. The 5160 refuses to start (beeeeeep) while the clone starts (beep) but no output from the VGA card (I tested the card into another PC and it works fine). Any idea?
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Start a new thread for this.
 
Scali said:
Not that hard if you know that the Commodore 1084S/Philips CM8833 is CGA-compatible.
They are very common, because they were the 'default' monitor for Commodore Amiga and C128.
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Nice, I didn't know.
Must it be the 1084S or a simple 1084 will be ok? The "S" stands for Stereo or I'm wrong?
 
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