Editing IBM 1620 (section)

===General===
The FORTRAN II compiler and SPS assembler were somewhat cumbersome to use<ref>{{cite book |url=http://www.bitsavers.org/pdf/ibm/1620/C26-5619-1_fortran.pdf |series=IBM Systems Reference Library |title=1620 FORTRAN (with FORMAT) |pages=51–56 |archive-url=https://web.archive.org/web/20090109151231/http://www.bitsavers.org/pdf/ibm/1620/C26-5619-1_fortran.pdf |archive-date=2009-01-09 |url-status=live}}</ref><ref>{{cite book |url=http://www.bitsavers.org/pdf/ibm/1620/C26-5876-2_FORTRAN_II_Mar65.pdf |series=IBM Systems Reference Library |title=IBM 1620 FORTRAN II Programming System Reference Manual |pages=22–28 |archive-url=https://web.archive.org/web/20090109145636/http://www.bitsavers.org/pdf/ibm/1620/C26-5876-2_FORTRAN_II_Mar65.pdf |archive-date=2009-01-09 |url-status=live}}</ref> by modern standards, however, with repetition, the procedure soon became automatic and you no longer thought about the details involved.

{| class="wikitable"
|-
!FORTRAN II compilation procedure
!Notes
|-
|Set the Program Switches as follows:

#''OFF'' (No Source listing)
#''OFF'' (No Batch compilation)
#''OFF'' (Source is entered from cards)
#''OFF'' (Only used if 3 is ''ON'')
|Pass I options
|-
|Set Overflow Check switch to Program and all others to Stop
|
|-
|Press ''Reset''
|
|-
|Load blank cards (face down 12-edge first) into the Punch hopper then press ''Punch Start''
|
|-
|Load Pass I of the compiler (face down 9-edge first) into the Read hopper then press ''Load''
|Wait for Pass I to load and print on the typewriter "ENTER SOURCE PROGRAM, PRESS START"
|-
|Remove Pass I of the compiler from the Read stacker
|
|-
|Load the program source deck (face down 9-edge first) into the Read hopper then press ''Start''
|Wait for Pass I to complete and print on the typewriter "TURN SW 1 ON FOR SYMBOL TABLE, PRESS START"
|-
|Turn Program Switch 1 ''OFF'' then press ''Start''
|If a symbol table listing is desired for debugging, turn Program Switch 1 ''ON'' instead. The symbol table listing will be printed on the typewriter.<br/>Wait for Pass I to print on the typewriter "END OF PASS 1"
|-
|Set the Program Switches as follows:
#''OFF'' (No statement number/address listing)
#''OFF'' (Not used)
#''OFF'' (No trace for IF statements)
#''OFF'' (No trace for arithmetic statements)
|Pass II options
|-
|Set Overflow Check switch to Program and all others to Stop
|
|-
|Press ''Reset''
|
|-
|Load blank cards (face down 12-edge first) into the Punch hopper then press ''Punch Start''
|
|-
|Load Pass II of the compiler (face down 9-edge first) into the Read hopper then press ''Load''
|Wait for Pass II to load
|-
|Remove Pass II of the compiler from the Read stacker
|
|-
|Remove the intermediate output of Pass I from the Punch stacker, then load it (face down 9-edge first) into the Read hopper and press ''Reader Start'' then ''Start''
|Wait for Pass II to complete and print on the typewriter "SW 1 ON TO PUNCH SUBROUTINES, PRESS START"
|-
|Remove the intermediate output from the Reader stacker
|
|-
|Turn Program Switch 1 ''ON'', load the Subroutine deck (face down 9-edge first) into the Read hopper, then press ''Reader Start'' then ''Start''
|Wait for Pass II to print on the typewriter "END OF PASS II"
|-
|Remove the Subroutine deck from the Reader stacker and the completed Object deck from the Punch stacker
|
|}

GOTRAN was much simpler to use, as it directly produced an executable in memory. However it was not a complete FORTRAN implementation.

To improve this various third-party FORTRAN compilers were developed. One of these was developed by Bob Richardson,<ref>{{cite book
   |title=History of Computer Graphics: Dlr Associates Series
   |url=https://books.google.com/books?isbn=1456751158  |isbn=978-1456751159
   |author=Dan Ryan  |date=2011 
   |quote=developed by Bob Richardson, a programmer at Rice University}}</ref><ref>User:Br6cycles3, in his/first and only edit to date (24 Feb 2019, 18:15) attempted to change the name in the article from ''Bob Richardson'' to ''Mike McCants'' and wrote in the summary: "Correct misattribution: I'm Bob Richardson and I know the programmer was actually Mike McCants."</ref> a programmer at [[Rice University]], the FLAG (FORTRAN Load-and-Go) compiler. Once the FLAG deck had been loaded, all that was needed was to load the source deck to get directly to the output deck; FLAG stayed in memory, so it was immediately ready to accept the next source deck. This was particularly convenient for dealing with many small jobs. For instance, at [[Auckland University]] a batch job processor for student assignments (typically, many small programs not requiring much memory) chugged through a class lot rather faster than the later [[IBM 1130]] did with its disk-based system. The compiler remained in memory, and the student's program had its chance in the remaining memory to succeed or fail, though a bad failure might disrupt the resident compiler.

Later, disk storage devices were introduced, removing the need for working storage on card decks. The various decks of cards constituting the compiler and loader no longer need be fetched from their cabinets but could be stored on disk and loaded under the control of a simple disk-based operating system: a lot of activity becomes less visible, but still goes on.

Since the punch side of the card reader-punch did not edge-print the characters across the top of the cards, one had to take any output decks over to a [[unit record equipment|separate machine]], typically an [[IBM&nbsp;557]] Alphabetic Interpreter, that read each card and printed its contents along the top. Listings were usually generated by punching a listing deck and using an [[IBM&nbsp;407]] accounting machine to print the deck.