Difference between revisions of "VERSAbus"
(Stubby, but there's not a lot on it) |
(Give better overview using the recently-found spec) |
||
| (3 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
[[Image:VERSAbus memory card.jpg|thumb|right|250px|VERSAbus memory card from Motorola Microsystems]] | [[Image:VERSAbus memory card.jpg|thumb|right|250px|VERSAbus memory card from Motorola Microsystems]] | ||
| − | The '''VERSAbus''' [[bus]] was created by [[Motorola]] for use on [[Motorola MC68000]]-based systems. Although it was not used by many products (although the [[Power 6/32]] did), it was influential as the electrical | + | The '''VERSAbus''' [[bus]] was created in 1979 by [[Motorola]], initially for use on [[Motorola MC68000]]-based systems. Although it was not used by many products (although the [[Power 6/32]] did), it was influential as the basis for the electrical functionality of the [[VMEbus]], used in many [[minicomputer]]s and specialist computers. |
| + | |||
| + | The VERSAbus had fairly ambitious goals when it was defined. In addition to immediate goals, it also put a fair amount of thought into long-term evolution; it was therefore an [[asynchronous]] bus. It was more powerful than most [[microcomputer]] buses at the time; it had a maximum 32-bit-wide [[data path]], and could use 16-bit, 24-bit, or 32-bit [[address]]es (see the [[4.3 BSD Reno]] document for a quick overview of the details). It also made provisions for sequential address access, to maximize performance; it also provided for a discrete priority [[arbitration]] unit, to allow use in [[multi-processor]] systems. Since the VERSAbus was principally used as an [[input/output]] bus, it also supported a fairly comprehensive [[interrupt]] structure. | ||
VERSAbus [[printed circuit board|cards]], in common with many card systems of that era (such as [[Digital Equipment Corporation|DEC]] [[DEC card form factor|standard cards]]), used [[etch]] fingers on one edge of the card, to make electrical contact with the bus; they measured 14.5 by 9.25 inches. | VERSAbus [[printed circuit board|cards]], in common with many card systems of that era (such as [[Digital Equipment Corporation|DEC]] [[DEC card form factor|standard cards]]), used [[etch]] fingers on one edge of the card, to make electrical contact with the bus; they measured 14.5 by 9.25 inches. | ||
| Line 9: | Line 11: | ||
== External Links == | == External Links == | ||
| + | * [https://bitsavers.org/pdf/motorola/versabus/M68KVBS_VERSAbus_Specification_Manual_Jul81.pdf VERSAbus Specification Manual] | ||
* [https://www.sciencedirect.com/science/article/abs/pii/0141933182904902 VERSAbus - a multiprocessor bus standard - and VMEbus - its Eurocard counterpart] | * [https://www.sciencedirect.com/science/article/abs/pii/0141933182904902 VERSAbus - a multiprocessor bus standard - and VMEbus - its Eurocard counterpart] | ||
| + | * [https://www.tuhs.org/cgi-bin/utree.pl?file=4.3BSD-Reno/src/share/doc/smm/01.setup/tahoe/1.t Installing/Operating 4.3BSD] - contains a moderately detailed description of the VERSAbus | ||
[[Category: Buses]] | [[Category: Buses]] | ||
Latest revision as of 17:53, 23 December 2024
The VERSAbus bus was created in 1979 by Motorola, initially for use on Motorola MC68000-based systems. Although it was not used by many products (although the Power 6/32 did), it was influential as the basis for the electrical functionality of the VMEbus, used in many minicomputers and specialist computers.
The VERSAbus had fairly ambitious goals when it was defined. In addition to immediate goals, it also put a fair amount of thought into long-term evolution; it was therefore an asynchronous bus. It was more powerful than most microcomputer buses at the time; it had a maximum 32-bit-wide data path, and could use 16-bit, 24-bit, or 32-bit addresses (see the 4.3 BSD Reno document for a quick overview of the details). It also made provisions for sequential address access, to maximize performance; it also provided for a discrete priority arbitration unit, to allow use in multi-processor systems. Since the VERSAbus was principally used as an input/output bus, it also supported a fairly comprehensive interrupt structure.
VERSAbus cards, in common with many card systems of that era (such as DEC standard cards), used etch fingers on one edge of the card, to make electrical contact with the bus; they measured 14.5 by 9.25 inches.
External Links
- VERSAbus Specification Manual
- VERSAbus - a multiprocessor bus standard - and VMEbus - its Eurocard counterpart
- Installing/Operating 4.3BSD - contains a moderately detailed description of the VERSAbus
