# UNDOCTL System Variable [GstarCAD 2020](Help%20System/GSTARCAD/2020/Index.md) → [System Variables](Help%20System/GSTARCAD/2020/System%20Variables/(System%20Variables).md) → [U](Help%20System/GSTARCAD/2020/System%20Variables/U/(U).md) ## Function Description: The UNDOCTL system variable is used to display options used in UNDO command. (Read-Only) | | | | --- | --- | | Type | Integer | | Saved in | Not saved | | Initial value | 53 | The setting is stored as a bitcode using the sum of listed system variable values. ## System Variable Value: **0:** turn off UNDO **1:** turn on UNDO **2:** only one command could be undone **4:** only one command could be undone **8:** one group is active **16:**treat ZOOM and PAN as one single action **32:** treat ZOOM and PAN as one single action --- ## Other versions with matching text [GstarCAD 2016](../../../2016/System%20Variables/U/UNDOCTL%20System%20Variable.md) · [GstarCAD 2017](Help%20System/GSTARCAD/2017/System%20Variables/U/UNDOCTL%20System%20Variable.md) · [GstarCAD 2018](Help%20System/GSTARCAD/2018/System%20Variables/U/UNDOCTL%20System%20Variable.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/System%20Variables/U/UNDOCTL%20System%20Variable.md) · [GstarCAD 2021](Help%20System/GSTARCAD/2021/System%20Variables/U/UNDOCTL%20System%20Variable.md)