Hi floors_u,
Truthfully, I was not familiar with foolscap paper, but I did some research and found the following on Wikipedia;
Foolscap folio (commonly contracted to foolscap or folio) is paper cut to the size of 8 1/2 × 13 1/2 in (216 × 343 mm) (for "normal" writing paper, 13" × 8"). This was a traditional paper size used in Europe and the (British) Commonwealth, before the adoption of the international standard A4 paper (the most common standard size in the world).
Ring binders or lever arch files designed to hold Foolscap folios are often used to hold A4 paper (210 mm × 297 mm). The slightly larger size of such a binder offers greater protection to the edges of the pages it contains.
A full foolscap paper sheet is actually 17 × 13 ½ in (432 × 343 mm) in size, and a folio sheet of any type is half the standard sheet size or a subdivision of this into halves, quarters and so on.
In Brazil, the 8 1/2 by 13 inches (215.9 mm × 330.2 mm) paper size is usually named Folio, and it is also sometimes called Ofício II, a reference to the 8 1/2-by-14-inch (215.9 mm × 355.6 mm) paper size (which is named Legal but in Portuguese is better known as Ofício).
In Venezuela, the 8 1/2 by 13 inches (215.9 mm × 330.2 mm) paper size is named Oficio. While laws expressly permit any paper size, public offices require all documents to be presented in Oficio paper size
It looks like different regions of the world define it differently. I checked the specifications of the 8500a and found the following;
Looks to me like Legal is the closest at 216mm x 356mm. With this being said, according to the specs it is not a supported paper size, but you might be able to create a custom paper size.
The following document explains how to print on custom paper sizes using paper settings options in the printer software. You can create custom paper sizes on computers running Windows 7, Windows 8, and Mac OS X. Create Custom Paper Sizes in Windows 7, Windows 8, and Mac OS X.
I know this is not likely the straight forward answer you were seeking, but I hope this information is helpful. To summarize, it may or may not work, but if there is any chance if it working, it will need to be done through a custom paper size.
Please let me know if this resolves the issue.
EDIT: My original response was specific to printing, I zeroed in on the subject line and realize now that you are actually trying to copy..... my apologies. You would not be able to copy as the printer would not have the option to choose the foolscap paper size on the front panel. You could try to scan it into the computer and them print it using the information I originally posted! Best of luck!