How to fill in advance unknown number of bytes in TASM?

Question

assembler

I read an article on Habré Writing our own OS .
There was a loader code for yasm . And since the code is located in the boot sector, we must have the signature 55 AA at the end of this sector . On yasm , this is done with the times directive .
times :
times 0x1FE- times +start db 0
And how to implement the initialization of these last two bytes with the assembler directive tasm ? I know that there is dup , but how to use it in this case?
.code
org 7c00h
start:
;======code======
;======data======
;fill to end of sector-2 bytes with zeros magic
db 55 , AA
end start \source\boot, nothing but dissimilar quantities of goodness advised by Google!