SCAN$ is a set of reentrant assembly language subroutines for scanning ASCII or Fieldata images. Available functions include the translation and copying of characters, the decoding of integer and real numbers, and the extraction of one or more characters under programmer control. Certain SCAN$ functions parallel or complement those of EDIT$; however, the two routines will not conflict, since SCAN$ uses a different set of pointer registers (X4-X6 vs. EDIT$'s X1-X3).

There are four relocatable elements in the SCAN$ package: SCAN$ (194 words), for scan mode initiation and termination, column pointer maintenance, and single character extraction; SCAN$XL (144 words, including an external reference to TABLE$ in SYSLIB), for translating between ASCII and Fieldata; SCAN$C (313 words), containing the functions for multiple character extraction and integer decoding; and SCAN$F (171 words), for decoding real numbers. There is also a MASM procedure element, SCAN$P, with procs for generating calls to the various SCAN$ functions.