SYSIN
Spooled system input in OS/360 and successors
title: "SYSIN" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["ibm-software"] description: "Spooled system input in OS/360 and successors" topic_path: "general/ibm-software" source: "https://en.wikipedia.org/wiki/SYSIN" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Spooled system input in OS/360 and successors ::
In OS/360, System Input (SYSIN) datasets are spooled direct-access storage device (DASD) data sets managed by the operating system. They are spooled by system readers, which typically read from card readers, although they can also read from magnetic tape. The support in OS/VS2 R1 (SVS) is essentially the same. The programs Attached Support Processor (ASP) and Houston Automatic Spooling Priority (HASP){{cite book | title = OS/VS2 HASP II Version 4 User's Guide - Program Number 370H-TX-001 - VS2 SVS Release 1.7 | id = GC27-0052-0 | section = SYSIN Data | section-url = http://www.bitsavers.org/pdf/ibm/370/hasp/GC27-0052-0_HASP_II_Version_4_Users_Guide_Sep76.pdf#page=20 | url = http://www.bitsavers.org/pdf/ibm/370/hasp/GC27-0052-0_HASP_II_Version_4_Users_Guide_Sep76.pdf | publisher = IBM | series = Systems | access-date = August 1, 2025 usurp the spooling functions of OS/360 and SVS, maintaining SYSIN datasets with their own SPOOL mechanisms.
In OS/VS1, SYSIN datasets are managed by Job Entry Subsystem 1 (JES1), retaining many of the same operator commands but replacing the SPOOL mechanism.
In MVS, OS/VS2 R2 and later, SYSIN datasets are managed by a Job Entry Subsystem (JES2 or JES3), retaining many of the HASP or ASP operator commands and providing their own SPOOL mechanisms.
SYSIN also refers to and JCL statements, and many programs expect an allocation with ddname SYSIN.
DOS does not support spooling, but several spooling programs are available for it, e.g., Grasp, POWER.
References
;OS360OpRefOS :{{cite book | title = IBM System/360 Operating System: Operator's Reference - OS Release 21 | url = http://bitsavers.org/pdf/ibm/360/os/R21.0_Mar72/GC28-6691-3_OS_Operator_Reference_Release_21_Mar72.pdf | series = Systems Reference Library | publisher = IBM | ref = | access-date = July 21, 2025 ;OSVS1Features :{{cite book | title = OS/Virtual Storage 1 - Features Supplement | id = GC20-1752-0 | date = August 1972 | edition = First | url = http://bitsavers.org/pdf/ibm/370/OS_VS1/GC20-1752-0_OS_VS1_Features_Supplement_Aug72.pdf | series = Systems | publisher = IBM | ref = | access-date = September 2, 2025
Citations
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