Motorola 88000
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (September 2020) |
Designer | Floating point | 32 80-bit (88110 only) |
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The 88000 (m88k for short) is a
History
Background
Motorola entered the 1980s in a position of strength; their recently-introduced Motorola 68000 easily outperformed any other microprocessor on the market, and its 32-bit architecture was naturally suited to the emerging workstation market. Intel was not moving aggressively into the 32-bit space, and the companies that did, notably National Semiconductor, botched their releases and left Motorola in control of everything that was not Intel. At the time, Intel held about 80% of the overall computer market, while Motorola controlled 90% of the rest.
Into this came the early 1980's introduction of the RISC concept. At first, there was an intense debate within the industry whether the concept would actually improve performance, or if its longer
This shift in the market had the potential to lock Motorola out of the workstation market, one of its only strongholds and among its most lucrative. Apple remained the company's only large vendor outside the workstation space; other users of the 68000, notably Atari Corporation and Commodore International, were floundering in a market that was rapidly standardizing on IBM PC compatibles.
Motorola's approach
RISC designs were a conscious effort to tailor the processor to the types of operations being called by the
Motorola's articles on the 88000 design speak of single-cycle instructions, large processor register files and other hallmarks of the RISC concept, but don't mention the word "RISC" even once.[2] As existing RISC designs had entered the market already, the company decided that they would not attempt to compete with these and would instead produce the world's most powerful processor. To do this, they took design notes from one of the fastest computers of a previous era, the CDC 6600 supercomputer. In particular, they adopted the 6600's concept of a scoreboard. Scoreboarding allowed the CPU to examine the instruction's use of registers and immediately dispatch those that did not rely on previous calculations that were not yet complete; this allowed the instructions to be re-ordered to allow ones that had their required data to run while others had their data loaded from the cache or memory. This instruction reordering could improve usage as much as 35%.[3]
The design also used separate data and instruction address busses. This was costly in terms of pin count; both the instruction and data caches had 32 pins for their address and 32 pins for the data, meaning the complete system used 128 pins on the "P-bus". This design was based on the observation that only about one-third of operations were memory-related; the rest were operating on data already read. This strongly favored having a dedicated instruction pathway to an external instruction cache. The caches, and associated memory management units (MMU) were initially external, a cache controller could be connected to either the data or instruction busses, and up to four controllers could be used on either bus. Internally there were three 32-bit busses, connected to the internal units in different ways as required for reading and writing data to the registers.[4]
Another feature of the new design was its built-in support for specialized co-processors, or "special function units", or SFUs.
Release
By 1987 it was widely known that Motorola was designing its own RISC processor. Referred to by the computer industry as the "78000",[a] an homage to the earlier 68000,[1] it became the 88000 when it was released in April 1988.
As a side-effect of the complexity of the design, the CPU did not fit on a single chip. The 68030, released a year earlier, had 273,000 transistors, including the
Aimed at the high-end of the market, it was claimed to be the fastest 32-bit processor in the world when it was released. Running at 20 MHz, it reached 34,000
At the time, Motorola marketed the 88000 strictly to the high-end of the market, including "telecommunications, artificial intelligence, graphics, three-dimensional animation, simulation, parallel processing and supercomputers", while they suggested the existing 68k series would continue to be used in the workstation market. Instead, most potential customers ignored the 88000,[7] and the system saw little use.
Re-release
As the original release saw next to no use outside Motorola's own products, and those traditional customers were starting to move to other RISC designs, the company re-launched the design in a single-chip form, the MC88110. In the late 1980s, several companies were actively examining the 88000 series for future use, including
There was an attempt to popularize the system with the 88open group, similar to what Sun Microsystems was attempting with their SPARC design. It appears to have failed in any practical sense.[9]
Abandonment
In the early 1990s Motorola joined the
Architecture
Like the 68000 before it, the 88000 was considered to be a "clean" design. It is a pure 32-bit load/store architecture with separate instruction and data caches (Harvard architecture)[12], and separate data and address buses. It has a small, powerful command set and uses a flat address space.
An unusual architectural feature is that both integer instructions and floating-point instructions use the same register file.
Implementations
The first implementation of the 88000 ISA was the
This was later addressed by the
An implementation for embedded applications, the MC88300, was under development during the early 1990s, but was eventually canceled. Ford Motor Company had planned to use the chips, so they were offered a PowerPC design as a replacement, which they accepted.[14]
Products and applications
Motorola released a series of
Major 3rd party users were limited. The only widespread use would be in the
The MC88110 made it into some versions of a never released
Most other users were much smaller. Alpha Microsystems originally planned to migrate to the 88K architecture from the Motorola 68000, and internally created a machine around it running UNIX System V, but it was later scrapped in favour of later 68K derivatives.[16] NCD used the 88100 (without the 88200) in its 88K X-Terminals. Dolphin Server, a spin-off from the dying Norsk Data, built servers based on the 88k. Around 100 systems were shipped during 1988-1992.
In the embedded computer space, the "Tri-channel VMS Computer" in the
Operating system support
Motorola released its own UNIX System V derivative, System V/88, for its 88000-based systems. There were two major releases: Release 3.2 Version 3 and Release 4.0 Version 3.[18] Data General AViiON systems ran DG/UX. OpenBSD ports exist for the MVME systems,[19] LUNA-88K workstations,[20] and Data General AViiON systems.[21] At least one unofficial experimental NetBSD port exists for the MVME systems.[22]
Notes
- ^ It is not clear whether this was an official name or not.
References
Citations
- ^ a b c d Lid.
- ^ Alsup 1990.
- ^ Alsup 1990, p. 51.
- ^ a b c Alsup 1990, p. 49.
- ^ "MC88100 RISC Microprocessor User's Manual" (PDF). p. 81(3-26). Retrieved 2023-12-21.
- ^ "MC88100 RISC Microprocessor User's Manual" (PDF). p. 88(3-33). Retrieved 2023-12-30.
- ^ a b April.
- ^ Volume.
- ^ Updegrove, Andrew (March 2006). "Standards Wars: Situations, Strategies and Outcomes" (PDF). ConsortiumInfo.org. p. 7. Archived from the original (PDF) on 2016-03-03. Retrieved 2009-06-16.
- ^ Cox, Steven (October 19, 2021). "CPU of the Day: Motorola XC88110 88000 RISC Processor". Retrieved 2023-08-25.
- ^ Zipper, Stuart (May 24, 1993). "Motorola PowerPC deal with Ford raises questions on 88K RISC fate". Electronic News. Retrieved 2009-06-16.[permanent dead link]
- ^ "Figure 1-2 and §1.2.7 Multiple External Buses". MC88100 RISC Microprocessor User's Manual, Second edition (PDF). 1990. Retrieved 25 August 2023.
- ^ Papadopoulos; et al. (July 28, 1993). "*T: Integrated Building Blocks for Parallel Computing" (PDF). Massachusetts Institute of Technology. Retrieved 2009-06-16.
- ^ Garfinkel, Simson (June 1992). "Motorola looks to 68060 chip". NeXTWORLD.
- ^ Marshall, Martin (April 24, 1989). "Tektronix Unveils Family Of Graphics Workstations". InfoWorld.
- ^ "AMPM: The Alpha Micro Pageant of Machines". The Alpha Micro Phun Machine.
- ^ Nobbs, Steven G. "PSC Implementation and Integration" (PDF). NASA. p. 63. Retrieved 2009-06-16.
- Motorola Computer Group. Archived from the originalon May 5, 2006. Retrieved 2009-06-16.
- ^ OpenBSD/mvme88k
- ^ OpenBSD/luna88k
- ^ OpenBSD/aviion
- ^ NetBSD/m88k Archived 2013-01-12 at archive.today Unofficial port of NetBSD 3.x
Bibliography
- Alsup, Mitch (June 1990). "Motorola's 88000 Family Architecture". IEEE Micro. 10 (3): 48–66. S2CID 30607775.
- "Lifting The Lid Off The Motorola 88000 – To Find Do-It-Yourself Co-Processors". TechMonitor. 14 September 1988.
- "Motorola's 88000 Risc In Full Volume Production". TechMonitor. 27 June 1989.[permanent dead link]
- "Motorola's Risc, Set To Go In April, Is Tailored For Unix". TechMonitor. 18 February 1988.
External links
- m88k website m68k/m88k reference website
- Dolphin m88k Dolphin Server Technology
- Badabada.org about m88k hardware and computers