Editing IBM 1620 (section)

===IBM 1621/1624 Paper Tape reader/punch===
[[File:IMB1620 and IBM 1621 with paper tape.jpg|thumb|User holding paper tape at the IBM 1620 with the IBM 1621 paper tape reader in background, IBM headquarters, White Plains, NY, 1961]]

The '''IBM 1621 Paper Tape Reader''' could read a maximum of 150 characters per second;<br/>The '''IBM 1624 Paper Tape Punch''' could output a maximum of 15 characters/second.<ref name=IBM.intro59/>

Both units:
* could handle eight-channel paper tape
* performed self-checking to ensure accuracy
* accommodated both numerical and alphabetic information in single-character coding.

The [[IBM 1621|1621]] Tape Reader and [[IBM 1624|1624]] Tape Punch included controls for:
* Power switch – If "on" the unit reader is powered up when the CPU is powered on.
* Reel-Strip switch – This switch selects whether Reels or Strips of paper tape are used.
* Reel power key – Applies power to the supply and takeup Reels to position the tape for reading and places the reader in ready state.
* Non-process runout key – Feeds tape until the reader is empty and takes the reader out of ready state.

{| class="wikitable"
|-
!Bootstrap procedure
!Notes
|-
|Press ''Insert''
|Unlocks typewriter keyboard and shifts into numeric mode.
|-
|Type 36xxxxx0030049yyyyy<br/>&nbsp;
|xxxxx is the address to load the tape into.<br/>yyyyy is the address to begin execution.
|-
|Press ''Release''
|Locks typewriter keyboard.
|-
|Press ''Start''
|Begin execution.
|}