Does the Win98 clipboard have a fixed maximum capacity, regardless of available RAM?

Edited October 19, 201015 yr by chromatic47

256MB is absolute maximum afaik.

I find my system is freezing if I try to copy a large image to the clipboard, and by large I mean only about 30MB, and this despite the fact I have 1GB or more of free physical RAM when I do so. Photoshop 7 will not allow such an image to be copied to the system clipboard at all, preventing such a freeze. I think the actual limit is actually something like 25.6 MB rather than 256MB.

On Windows ME not 98 btw.

Edited October 13, 201015 yr by loblo

I run into this problem when I use the snapshot feature of Foxit PDF Reader. If I set the DPI capture resolution too high, it "copies" the data to the clipboard per Foxit interface, and other applications (Irfanview, Paint Shop Pro, Photoshop) show Paste As New option in menu, but then respond "Unable to paste from the clipboard" if the command is executed. Gradually lowering the Foxit DPI capture resolution finally allows the data to be pasted.

Edited October 18, 201015 yr by chromatic47

Maybe that's a bitmap size limit, not the clipboard. Do a test with huge text fragment. Or maybe I'll do it myself on Friday or Saturday. Though my Win98 PC has 256 Mb RAM only.

I did a test copying/pasting a 32-bit 10" x 10" image back and forth between Paint Shop Pro 7.04 and Irfanview 4.27 at increasing DPI resolutions. The results are the same whether the image is copied initially from Irfanview or PSP.

Results:

220 DPI: 14,520,040 Bytes

230 DPI: 15,870,040 Bytes

235 DPI: 16,572,240 Bytes

236 DPI: 16,708,840 Bytes

... all copy and paste OK.

237 DPI: 16,855,480 Bytes

...will not copy to clipboard from either program.

I haven't bothered to narrow it down more exactly since it appears likely from the results that the actual limit on this machine is 16 MiB -- 16,777,216 Bytes.

Now I am curious if this limitation can be exceeded with a system tweak. It's cramping my style. B)

While that could be a clipboard limit, it doesn't need to be. There is a limitation on bitmap handle size: link

There is a limitation on bitmap handle size: link

From your link:

"Windows 95/98/Me: The created bitmap cannot exceed 16MB in size."

Well that explains that. Thanks for the info!

Edited October 19, 201015 yr by chromatic47

I have made a test with huge text fragment. I successfully copied and pasted ~12 Mb and ~25 Mb plain text pieces. So, clipboard size is definitely not limited to 16 Mb. The tests were performed with AkelPad 1.0.4 text editor. The latest version 4.4.4 hangs up OS even with 9 Mb fragment. 12 Mb were copied in less than one seconds, and pasted in 10-20 seconds. 25 Mb fragment was copied in several seconds and pasted in 4-5 minutes, so I don't think I'll perform test with a larger fragment - I waited too long even for this test. My Windows 98 computer (real, not virtual) has 256 Mb RAM.