I don't know of any, but if you happen to have a program for 8088+CGA or such, it will be quite trivial to modify it to support Hercules.

An archived page from old MobyGames has a few screen capture utilities:
https://web.archive.org/web/20040703055618/ht … om/info/faq6#f8

CAMERA.COM should be suitable for your purpose. It has limited output formats so you may have to convert to the format you want. I think the program was originally included with Deluxe Paint and/or Deluxe Paint 2 by EA.

I also found 'hercap10.zip' (Google for it, you'll find it). Never tried it myself, but perhaps it will work.

Back in the day I used 'Grabber' (Google for 'Grabber for DOS') which will work for VGA/EGA/CGA but can't recall ever using it for Hercules.

I have original Hercules disk images if you need.

Or you could just take screenshots in an emulator

Thank you all for your suggestions, I found some time to give them a try.

It seems there is some issue here... First of all, both PC's I'm interested in are just XT clones, they don't have an original Hercules adapter. Still, every single native Hercules game works. They are both PC's I owned in the late 80's-early 90's and also back then I didn't run into any trouble running Hercules stuff. I did try "CAMERA" and "hercap10" as they are 2 utilities I wasn't aware of and really seemed promising. Basically they were the only ones actually "working" and thanks again for pointing them out.

So, why the quotes? This is what I get from both of them, no matter what I try to grab (command prompt, text mode app like Norton Commander, game):

I don't know what to think right now, it's not only one utility to take the blame. Maybe the adapter, not being an original Hercules, is the problem?
I'm well aware I could just use dosbox or something, but I'd really like to have the option to get screenshots from the real thing.

If you get the proper graphics on screen, the adapter shouldn't be the problem. These old graphics cards are very simple: Whatever is in video memory, appears on your monitor. So, the capture utilities simply fail to copy the memory contents to a file.

I am not sure why this is happening... Perhaps because your card is MORE than just Hercules? Most clones I have seen, were combined CGA/Hercules cards. Perhaps the utilities are confused, and wrongly assume that it is a CGA card, and copy the wrong memory...

Because, as I understand, you always get the EXACT same image? No matter what you try to grab? That would mean that whatever memory it's grabbing from, is not changed when the contents of the screen change. So it simply grabs the wrong memory.

I see your point here, it totally makes sense. Both XT clones have an "MDA" adapter, not one of those CGA/Hercules combos that you can select the mode via dip switches or software. I always thought of them as a Hercules compatible adapter (games etc all function as intended when selecting the Hercules mode), I hope I'm not missing something important here.

The screen grabs are not EXACTLY like the one posted above, but they all follow this pattern and look similar. Oh well, practically it's not a big deal but it's intriguing...

konc wrote:

I see your point here, it totally makes sense. Both XT clones have an "MDA" adapter, not one of those CGA/Hercules combos that you can select the mode via dip switches or software. I always thought of them as a Hercules compatible adapter (games etc all function as intended when selecting the Hercules mode), I hope I'm not missing something important here.

Well, if you get graphics when you select Hercules mode in games, then the cards must be Hercules-compatible. MDA cannot do graphics at all.
So I guess there is some kind of incompatibility between your specific Hercules-compatible adapter and the screen grab tools you are using.
Hercules' framebuffer is normally at segment B000h, and if you do not have a CGA card installed, you have a backbuffer at B800h as well.
Doign a screendump is as simple as writing the 32k of memory from B000h to disk, because that is what you see on screen (I assume most early games don't use double-buffering, because you couldn't do that on CGA either, and Hercules stuff is generally just backported from CGA).
Do you have any screen grab tool with source code? It's not too difficult to write something like that anyway. But it would be even simpler if I just had the source code and could inspect to see what it is trying to do, and why it doesn't generate the expected images.

Alternatively, it could be something as stupid as your dumps being correct, but the program you're using to view them is not (Hercules has a 720x348 resolution with a strange 4-way interleaving for the scanlines, so trying to interpret it as 320x200 or 640x200 CGA image is going to give you a big mess. Then again, the image you posted seems to have very repetitive patterns, doesn't look like anything graphical at all).

Scali wrote:

Alternatively, it could be something as stupid as your dumps being correct, but the program you're using to view them is not

Thankfully this doesn't seem to be the case, which saved me some embarrassment 😀 One of the capture utilities grabs in .LBM, the other in .TIFF. I used both Deluxe Paint and some modern utility to open the images and they were identical for the same capture.

Scali wrote:

Do you have any screen grab tool with source code? It's not too difficult to write something like that anyway. But it would be even simpler if I just had the source code and could inspect to see what it is trying to do, and why it doesn't generate the expected images.

HerCap (attached, this is what I’m mostly trying to use) originates from an older PC Magazine’s utility, states in its .doc it’s free and also includes the source .ASM. From what I saw it does what it’s supposed to do, when capturing page 0 it starts from B000h, stores in mem 32K and then writes the file. My assembly knowledge is really limited though and my experience ended with uni courses.

Now, are you ready for this? After seeing the code I thought to give it one more try. I started grabbing screens including a DOS prompt & Norton Commander (text mode). Ended up with something like 20 images after attempting ~15 games. From ALL of those, only Prince of Persia was grabbed correctly. This surpasses me…

Well, that is interesting. So at least Prince of Persia does what you expect it to do.
Have you also tried to make it capture with page 1?
I wonder if it was common for games to configure page 1 instead of 0, because then the segment would be the same as their CGA code.
That is the only explanation I can think of why B000h doesn't contain any game graphics in most cases.

Good to see Prince of Persia in Hercules mode. Brings back memories 😀.

You can load HERCAP with parameter /1 to grab page 1 (and /0 for page 0). Using DOSBox I get correct files with page 0 for Prince (just like you) and empty files with page 1 (which seems right).

By the way: the .TIF files can be opened with Paint in Windows 8.1. The default Windows viewer doesn't show the correct image, though.