AMD Am29000

They were, for a time, the most popular RISC chips on the market,[citation needed] widely used in laser printers from a variety of manufacturers.

[4] The 29050 was notable for being early to feature a floating point unit capable of executing one multiply–add operation per cycle.

Values being returned from the routines would be placed in the "global page", the top eight registers in the SPARC (for instance).

When the window filled the calls would be pushed off the end of the register stack into memory, restored as required when the routine returned.

Generally, the 29000's register usage was considerably more advanced than competing designs based on the Berkeley concepts.

Any register could be used for this purpose, allowing the conditions to be easily saved at the expense of complicating some code.

A 64-entry translation lookaside buffer (TLB) retained mappings from virtual to physical addresses, and upon an untranslated address being encountered, the resulting TLB "miss" would cause the processor to trap to a software routine responsible for providing any appropriate mapping to physical memory.

[7] Some products in the 29000 family provided only 16 TLB entries to be able to dedicate part of the silicon to peripherals.

Later the Am29040 was released at 33, 40, and 50 MHz, being like the Am29030 except for featuring a 4 KB data cache, a multiplication unit, and a few other enhancements.

Positioned as a product for "medium- to high-performance embedded applications" with potential for use in Unix workstations,[7] the 29000 was used in a variety of products such as X terminals, laser printer controller cards, graphics accelerator cards, optical character recognition solutions, and network bridges.

[25] Such accelerator cards offered performance several times that of the Macintosh II itself and benchmarked competitively with RISC workstations such as the DECstation 3100.

However, the cost of a Macintosh II system combined with such a card approached that of established RISC workstations running Unix.

[26] The AT-Super was priced at around $4,600 and was reported as running Unix, competing with similar products employing Intel's i860 processor.