NCR Corp yesterday extended its highly successful line of Tower Unix supermicros with a Tower local area network family, and four new models that extend the top end support to 512 users. The networking products include a Tower File Server, Token-Ring Controller, Token-Ring NetBIOS and TCP/IP communications via Ethernet. The Tower File Server program, whih runs on whichever Tower you nominate to be a server, provides a transparent file system between MS-DOS and Unix, and is compatible with Expanded TowerNet and NCR Token-Ring nets, so that an MS-DOS user can use the server, which costs $1,230 from third quarter 1988. The Token-Ring Controller supports Towers on a Token-Ring, enabling MS-DOS or OS/2 micros on the ring to communicate with them: it is set for the second quarter at $2,195. The Token-Ring NetBIOS links the Tower File Server to the Token-Ring, arrives second quarter and costs $530. TCP/IP arrives at the same time. When you sell as many machines as NCR does with the Tower, you can’t rush to incorporate a new chip as soon as it arrives because there simply aren’t enough chips to meet your needs. Accordingly the new Tower models use the 25MHz 68020 rather than the 68030. Top of the new models is the 32/850, supporting up to 512 users; there are new mid-range 650 and 450 models, the former supporting 64 users against 48 on the 600, the latter 32 users against 16 on the 400. And a new entry 32/250 supports four users but is as powerful as the 600. Performance is also improved by use of an enhanced disk and tape subsystem to provide double the speed of the 400 and 600. The 32/850 comes with up to six 25MHz 68020 based applications processors, each with 8Mb to 16Mb memory, 40Kb cache and 68882 maths chip, a new file processor, up to 64Mb of system memory has new input-output hardware for external asynchronous devices, such as video display terminals or printers, but supports all 32/800 controllers, adaptors, processors, disk and tape drives and software, and is upgradeable from the previous line topper. Internal disk goes to 1.9Gb, external to 20Gb. It starts at $106,175 and ships in the third quarter. The 32/650 starts at $24,915 and the 32/450 at $15,565; they are also available as upgrades from the 600 and 400 respectively. Ships start in June. The 32/200 crashes the entry level to the line, coming in floppy- and tape-based models and weighing just 25 lbs. To be available in April it starts at $5,445.