Providing ad-hoc processing power for the management of the backing store is a well-known technique for increasing parallelism [1]. A further advantage is the modularized decomposition of functionalities, which ensures [2]. This may prove useful not only in the debug and test phases of system development, but also when performance analysis and tuning are involved. This paper presents a mass storage controller which includes not only DMA capabilities, but also a microprocessor (actually, an Intel 8086). In this way, the controller can carry out such device-related low-level activities as control of mechanical operations and management of interrupts from the disk. A further application concerns the total data transfer from one hard disk to another (the so-called copy-volume function). The controller is able to accomplish one such transfer with good performance and insensitivity to faults.
Contrary to the implications of the title and the abstract, the copy-volume function is not the salient issue of the paper. Furthermore, the approach adopted is worth consideration not only as far as minicomputer systems are concerned, but also in most applications involving mass storage devices and present-day microprocessors. Indeed, the main merit of the paper is the emphasis placed on this aspect of the design and implementation of computer architectures. On the other hand, a few decisions concerning the specific implantation presented in the paper are debatable. For instance, a few memory management functionalities, still left to the main processor, could perhaps be demanded to the controller. Unfortunately, the reasoning behind this and other outstanding design decisions cannot be argued from the short text of the paper. Moreover, little help ensues from the bibliography, where prior work on the same subject is poorly referenced.