"Comma expected after operand 1" when defining a series of bytes in NASM?

Question

According to NASM's documentation, the following allows me to define 64,000 uninitialized bytes at the label Vid:

Vid resb 64000

According to subsequent documentation, this should allow me to initialize those bytes to 0xFF instead:

Vid db 64000 dup (FFh)

This, however, yields the error error: comma expected after operand 1.

I have also tried:

• Adding a colon after the symbol name Vid
• Using 0 or a question mark for the default value instead of FF (although FF is my intended value)
• Using smaller numbers of bytes, such as 64
• Adjusting capitalization
• Rearranging my source file so that this directive appears in different sections, etc.
• Adding commas between 64000, dup, and (FFh) - which obviously does not work

I cannot find anything online suggesting that this syntax has changed or that there are any cases where it should not work.

As important background, I am compiling to a bin file and have the cpu 8086 directive in my source.

Answer 1

Converting comment to answer: DUP was only added to NASM with version 2.15 (released in June 2020). For compatibility with older versions, use TIMES, e.g. times 64000 db 0xff.