Hi guys, firstly, im very new with this language so im kinda lost. well i'm actually trying to modify a software programmed in idl. This software converts unformatted binary file into ascii type format. Now, the problem is that when a number in the binary file is too long, it will combine with the previous number which results only one number in ascii file. This is very problematic because i've created another program that reads and processes the ascii file, and this problem will cause a data shift. (1024 samples in binary file will be 1023 samples in ascii file, and i have hundreds of these samples) i include a pic to make it easier to understand: As you can see, the two highlighted numbers are combined. Whenever i try to read this data in IDL, the combined numbers will be skipped. ; field 12 Spectra = FLTARR(NbComp, NbSpect) READU, unit, Spectra IF (d EQ 1) THEN BEGIN PRINTF, output_unit, "" PRINTF, output_unit, "Block4 data" PRINTF, output_unit, "======" FOR i = 0, NbSpect-1 DO BEGIN PRINTF, output_unit, Spectra[*, i] ----> this is where i print the spectrum data into the ascii file. PRINTF, output_unit, "" ENDFOR ENDIF Now, my idea is to put more spaces between two numbers. But I don't know how to do it. Thanks in advance for any help