Conditions for use:

1. 16-bit units only (i.e. logical record header consists of 16-bit words)
2. No spanned headers
3. Always MLUSER words transferred to user (word 3 is header length). This may exceptionally lead to a program range error if the input buffer IBUF coincides with the end of the user program. Remedy: increase size of IBUF by 16*MLUSER/(no. of bits per word)
4. No headerless blocks
5. No old EP format
6. No unknown length records

In addition, no checks performed whether input unit, or whether header cut. Conditions 2. to 6. are always fulfilled when writing with EPIO, condition 1. is default when writing with EPIO.

Calls to this routine are entirely compatible with EPREAD calls.

CALL EPFRD (LUNIT,MODE,NW,IREC,IBUF,IERR)

Fast logical record data reading routine.

Input parameters:

UNIT

user unit number

MODE

one of 11, 12, 13 (see EPREAD)

/Input/Output buffer:

IBUF

user buffer

Output parameters:

NW

no. of words in IREC

IREC

record transferred to user

IERR

error number