Mac And Vax: The Road From Enemies To Brothers

Description

Understanding growing between the two companies for the need to integrate AppleTalk and DecNet protocols.

Main Article Text

The spread of Macintosh workstations alongside the mini Vax has convinced Digital Equipment to choose a path of cooperation with Apple Computers, rather than oppose the latter. At the beginning of the year, in fact, the two companies signed an agreement to integrate AppleTalk and DecNet protocols. The remaining aspects of the Mac-Vax connection are already possible thanks to the initiative of third parties, and the two newly allied friends have done nothing but formalize a trend already in place. Today, the most popular product application of this type is Apple Talk for VMS that reproduces, inside of the VMS operating system, the framework of all of the core functions of Apple-Talk. It will probably be the same software products made by Alisa Systems (221 E. Walnut St. – Suite 230, Pasadena, Calif. 91101, tel. 818 7929474) that will form the basis on which Apple and Digital will work; in particular Digital intends to add functions of higher architectural layers, integrating under VMS, also the file management structure of the AppleTalk filing protocol.
Afp, corresponds to the presentation level of OSI, allowing the network to bring to the management environment documents from the Apple environment, where each file is identified by name and the folder that contains it.

Let’s see what the current structure of AppleTalk for VMS is, so we can understand what the future releases could hold for the user. The product faithfully follows the settings of the ISO OSI model, which reproduces the four intermediate levels, i.e. data link, network, transport, and session. Within this range, we find the level of the network’s physical control that which is delegated to the various types of interface (see Article Three alternatives to connect the Macintosh network published in Italian PCWeek #22 dated 06.16.88), while above this range, we have the Afp (Presentation) and applicative programs for the user (application). On the inside of the Vax, we find that many processing jobs are generated, depending on the number of virtual nodes that one wants to emulate. In practice, the users working on Macintosh logs on to the disk of the mini as if the latter were a resource that a second operator owns but shares with others. Of course, this hypothetical other user none other than the same mini, which electronically simulates all the adjustments that a Macintosh performs when it acts as a network server. To simplify the management of the two environments, Apple Talk on one part and Vms for the other part create two separate lan. The first is the network that physically connects the various existing Macintoshes in the department; the second is the virtual network, electronically created internally in the Vax. The connection between the two is then realized by means of a classic bridge between networks. These settings are already quite functional and, thanks to its modularity, should not be difficult to expand, until it is able to encompass the Apf file system, but also the electronic mail services and the like offered by Vax … or else other applications.

Roberto Mazzoni