Editing NetWare (section)

=== {{anchor|2.10|2.11|2.12|2.15|2.2|SFT}}NetWare 286 2.''x'' ===
[[File:Novell_NetWare_2.2_floppies.jpg|thumb|right|upright=0.85|Floppy disks for NetWare 2.2]]
Advanced NetWare version 2.''x'', launched in 1986, was written for the then-new 80286 CPU. The 80286 CPU features a new [[16-bit]] protected mode that provides access to up to 16&nbsp;MiB RAM as well as new mechanisms to aid multi-tasking. (Prior to the 80286, PC CPU servers used the Intel [[8088]]/8086 [[8-bit|8]]-/16-bit processors, which are limited to an address space of 1&nbsp;MiB with not more than 640&nbsp;KiB of directly addressable RAM.) The combination of a higher 16&nbsp;MiB RAM limit, 80286 processor feature utilization, and 256&nbsp;MB NetWare volume size limit (compared to the 32&nbsp;MB that DOS allowed at that time) allowed the building of reliable, cost-effective server-based local area networks for the first time. The 16&nbsp;MiB RAM limit was especially important, since it makes enough RAM available for disk caching to significantly improve performance. This became the key to Novell's performance while also allowing larger networks to be built.

In a significant innovation, NetWare 286 is also hardware-independent, unlike competing network server systems. Novell servers can be assembled using any brand system with an Intel 80286 CPU, any [[Modified Frequency Modulation|MFM]], [[Run Length Limited|RLL]], [[Enhanced Small Disk Interface|ESDI]], or [[SCSI]] hard drive and any 8- or 16-bit network adapter for which NetWare drivers are available – and 18 different manufacturer's network cards were supported at launch.<ref name="NW2"/>

The server could support up to four network cards,<ref name="NW2"/> and these can be a mixture of technologies such as [[ARCNET]], [[Token Ring]] and [[Ethernet]]. The operating system is provided as a set of compiled [[object module]]s that required configuration and linking. Any change to the operating system requires a re-linking of the [[kernel (operating system)|kernel]]. Installation also requires the use of a proprietary low-level format program for [[Modified Frequency Modulation|MFM]] hard drives called COMPSURF.

The file system used by NetWare&nbsp;2.''x'' is [[NetWare File System]] 286, or NWFS&nbsp;286, supporting volumes of up to 256&nbsp;MB. NetWare&nbsp;286 recognizes 80286 [[protected mode]], extending NetWare's support of RAM from 1&nbsp;MiB to the full 16&nbsp;MiB addressable by the 80286. A minimum of 2&nbsp;MiB is required to start up the operating system; any additional RAM is used for [[File Allocation Table|FAT]], DET and file caching. Since 16-bit protected mode is implemented in the 80286 and every subsequent Intel x86 processor, NetWare&nbsp;286 version 2.''x'' will run on any 80286 or later compatible processor.

NetWare 2.''x'' implements a number of features inspired by [[mainframe computer|mainframe]] and [[minicomputer]] systems that were not available in other [[operating system]]s of the day. The ''[[System Fault Tolerance|System Fault Tolerance (SFT)]]'' features includes standard read-after-write verification (SFT-I) with on-the-fly bad block re-mapping (at the time, disks did not have that feature built in) and software [[RAID1]] (disk mirroring, SFT-II). The [[Transaction Tracking System]] (TTS) optionally protects files against incomplete updates. For single files, this requires only a file attribute to be set. Transactions over multiple files and controlled roll-backs are possible by programming to the TTS [[API]].

NetWare&nbsp;286&nbsp;2.''x'' normally requires a dedicated PC to act as the server, where the server uses DOS only as a [[boot loader]] to execute the operating system file {{mono|NET$OS.EXE}}. All memory is allocated to NetWare; no DOS ran on the server. However, a "non-dedicated" version was also available for price-conscious customers. In this, DOS&nbsp;3.3 or higher remains in memory, and the processor time-slices between the DOS and NetWare programs, allowing the server computer to be used simultaneously as a network file server and as a user workstation. Because all [[extended memory]] (RAM above 1&nbsp;MiB) is allocated to NetWare, DOS is limited to only 640&nbsp;KiB; [[expanded memory]] managers that used the MMU of 80386 and higher processors, such as EMM386, do not work; 8086-style expanded memory on dedicated plug-in cards is possible however. Time slicing is accomplished using the keyboard [[interrupt]], which requires strict compliance with the IBM PC design model, otherwise performance is affected.

Server licensing on early versions of NetWare&nbsp;286 is accomplished by using a key card. The key card was designed for an 8-bit ISA bus, and has a serial number encoded on a ROM chip. The serial number has to match the serial number of the NetWare software running on the server. To broaden the hardware base, particularly to machines using the IBM MCA bus, later versions of NetWare&nbsp;2.''x'' do not require the key card; serialised license floppy disks are used in place of the key cards.

Licensing is normally for 100 users, but two ELS versions were also available. First a 5-user ELS in 1987, and followed by the 8-user ELS&nbsp;2.12&nbsp;II in 1988.<ref name="NW_1989_ELS"/>