Editing DR-DOS (section)

==={{anchor|1.0}}PalmDOS===
In 1992 Digital Research, still under its old name but already bought by Novell in July 1991,<ref name="BW_1991"/><ref name="Scott_1991_Merger"/> also embarked on a spin-off product code-named "Merlin" and later released as NetWare PalmDOS 1, which, as its name implies, was a very resource-light DR&nbsp;DOS 6.0 derivative aimed at the emerging [[Palmtop]]/[[Personal digital assistant|PDA]] market.<ref name="CW_1992_PalmDOS"/>

PalmDOS was the first operating system in the family to support the new BDOS 7.0 kernel with native DOS compatible internal data structures instead of emulations thereof. Replacing the DOS emulation on top of a CP/M kernel by a true DOS compatible kernel helped a lot in improving compatibility with some applications using some of DOS' internal data structures and also was the key in reducing the resident size of the kernel code even further—a particular requirement for the PDA market. On the other hand, introducing a genuine [[Current Directory Structure]] ([[CDS (DOS technology)|CDS]]) imposed a limit on the depth of [[working directory|working directories]] down to 66 characters (as in MS-DOS/PC&nbsp;DOS), whereas previous issues of DR&nbsp;DOS had no such limitation due to their internal organization of directories as relative links to parent directories instead of as absolute paths.<ref name="Paul_1997_NWDOS7UN"/><ref name="Paul_1997_NWDOSTIP"/><ref name="4DOS_8.00_HELP"/> PalmDOS still reported itself as "PC&nbsp;DOS 3.31" to applications in order to keep the kernel small and not run into compatibility problems with Windows, which would expect the [[DOSMGR]] API to be implemented for any DOS version since 5.0.

As well as a ROM-executing kernel, PalmDOS had palmtop-type support for features such as [[PCMCIA]] [[PC Card]]s (with [[DOS Protected Mode Services|DPMS]] support), power management ([[BatteryMAX]] and the [[$IDLE$]] device driver with its patented dynamic idle detection<ref name="Dynamic_Idle_Detection"/> by Gross and John P. Constant), [[MINIMAX]] task switcher support for [[PIM (DOS technology)|PIM]] (Personal Information Modules) applications stored and executed from ROM via [[XIP]] ([[Execute-In-Place]]), etc.

The PCMCIA stack for PalmDOS was partially written by [[Ian H. S. Cullimore]], the original instigator of the PCMCIA/PC Card movement.