IBM PS/2 Model 70

File:IBM PS2 MCA Model 70, drives internal side-view.jpg and features the same tool-less construction.]]

File:8570a61 observe.png processor complex from a Model 70 386-A21. This complex also has an 80387 floating point unit installed.]]

Both variants of the Model 70, along with the rest of the PS/2 line, were developed at IBM's facility in Boca Raton, Florida. The original Model 70 386 was released on June 2, 1988.{{cite news | last=Lunan | first=Charles | date=June 3, 1988 | url=https://www.proquest.com/docview/389377920/ | title=IBM Adds Seven Units to PC Line | work=Sun Sentinel | page=1D | via=ProQuest}}{{cite magazine | last=Lunan | first=Charles | date=December 20, 1989 | url=https://www.proquest.com/docview/389312794/ | title=IBM Model Latest Entry in PC Race | magazine=Sun Sentinel | page=1D | via=ProQuest}} The chief engineer behind the Model 70 386 was Mark Dean, who previously headed development of the PS/2 Model 80, the PC AT and the ISA bus.{{cite web | last=Crothers | first=Brooke | date=August 10, 2011 | url=https://www.cnet.com/science/ibm-executive-says-pc-era-is-in-its-twilight/ | title=IBM executive says PC era is in its twilight | work=CNET | publisher=CBS Interactive | archiveurl=https://web.archive.org/web/20230601102124/https://www.cnet.com/science/ibm-executive-says-pc-era-is-in-its-twilight/ | archivedate=June 1, 2023}} The original Personal System/2 Model 70 386 was in development at IBM since 1986, along with the rest of the initial line-up of the PS/2.{{cite magazine | last=Forbes | first=Jim | author2=Stephen Kanzler | date=April 28, 1987 | url=https://link.gale.com/apps/doc/A4790118/GPS?sid=wikipedia | title=IBM to fill gap in PS/2 family with '386-based Model 70 | magazine=PC Week | volume=4 | issue=17 | pages=1 et seq | via=Gale}} The existence of prototypes of the Model 70 386 were known to select members of the press and industry insiders since April 1987, but it took until May 1988 for IBM to formally announce it.{{cite magazine | last=Forbes | first=Jim | author2=Linda Bridges | date=May 24, 1988 | url=https://link.gale.com/apps/doc/A6697693/GPS?sid=wikipedia | title=IBM will enter desktop derby with triple-crown PS/2 line | magazine=PC Week | volume=5 | issue=21 | pages=1 et seq | via=Gale}} In the interim, IBM released the PS/2 Model 80—the company's first Intel-based PC with the 32-bit 386 microprocessor. With its tower construction allowing for a greater number of Micro Channel expansion slots and drive bays IBM initially positioned the PS/2 Model 80 as a multiuser workstation. However, the company pivoted the machine toward server use the next year, with the Model 70 386 slotting into the role of a 32-bit workstation.

Both the Model 70 386 and the Model 70 486 feature the same case and tool-less construction as the Model 50 released earlier in April 1987.{{cite book | last=Byers | first=T. J. | date=1989 | url=https://books.google.com/books?id=ie-5ffW7ws8C | title=IBM PS/2: A Reference Guide | publisher=Intertext Publications | page=4 | via=Google Books | isbn=9780070095250}} The Model 70 386 was initially manufactured at IBM's facility in Boca Raton, Florida, along with the Model 50, the Model 30, the Model 60, and the Model 80. In early 1989, IBM moved manufacturing of PS/2s from Boca Raton to Raleigh, North Carolina, after having shut down their production lines reserved for computer systems in Florida to make way for other products.{{cite magazine | last=LaPlante | first=Alice | date=April 24, 1989 | url=https://books.google.com/books?id=XToEAAAAMBAJ&pg=PP1 | title=Dealers Report Model 80 Shortage | magazine=InfoWorld | volume=11 | issue=17 | pages=1, 93 | via=Google Books}}{{rp|1}} The hard drives used in the Model 70s were manufactured at IBM Japan's plant in Fujisawa, Kanagawa.

The Model 70 386 was plagued with several design defects from the time of its release. The Model 70 386-A21 in particular was problematic, with initial production runs possessing a defective processor complex slot that prevented the systems from functioning. These issues and more prompted suspension of production as well as numerous motherboard redesigns lasting two months in early 1989.{{cite magazine | last=LaPlante | first=Alice | date=March 13, 1989 | url=https://books.google.com/books?id=BjoEAAAAMBAJ&pg=PA194 | title=Design Flaws Plague Model 70-A21 | magazine=InfoWorld | volume=11 | issue=11 | pages=1, 89 | via=Google Books}}{{rp|1}} In June 1989, IBM issued a recall of certain submodels of the Model 70 386 possessing 120-MB hard drives, after users reported drive failures and a "10483" error code shortly after purchase. These failures were traced back to a manufacturing error at IBM Fujisawa; the fault was discovered to be oil lubricant breaching containment and leaking outside of the drives.{{cite news | author= | date=June 13, 1989 | url=https://www.proquest.com/docview/398097742/ | title=IBM to Replace Model 70 Drives Due to Oil Leaks | newspaper=The Wall Street Journal | page=1 | via=ProQuest}} While this leak was easily fixed and did not result in any data loss, it resulted in the recall of 25,000 units of the Model 70 386 that month.{{cite magazine | last=LaPlante | first=Alice | date=June 12, 1989 | url=https://books.google.com/books?id=jzAEAAAAMBAJ&pg=PP1 | title=IBM Reports Model 70 Disk Drive Problems | magazine=InfoWorld | volume=11 | issue=24 | pages=1, 105 | via=Google Books}}{{rp|1}}

In June 1989, IBM announced the 486/25 Power Platform. This was an upgrade package for the Model 70 386-A21 (see § Specifications for more details on the submodel) comprising a 25-MHz Intel 486 microprocessor on a CPU daughtercard (called a complex, in IBM parlance). This card plugs into a dedicated slot on the motherboard (a planar, in IBM parlance), replacing the 25-MHz 386 processor complex that the Model 70 386-A21 originally shipped with.{{cite magazine | last=Kvitka | first=Andre | author2=Daniel Sommer | date=November 13, 1989 | url=https://books.google.com/books?id=sTAEAAAAMBAJ&pg=PT168 | title=IBM's 486 Offers Sparkling Performance | magazine=InfoWorld| volume=11 | issue=46 | page=141 | via=Google Books}} This allows the Model 70 386 to run twice as fast as 386 machines clocked at 33 MHz, on top of giving the Model 70 386 the built-in floating point unit inherent to the i486. The 486/25 Power Platform was the first commercially available product to use the 486 processor, announced just two months after Intel publicly released the 486 processor and first shipping in early October 1989.{{cite magazine | last=LaPlante | first=Alice | date=June 26, 1989 | url=https://books.google.com/books?id=lTAEAAAAMBAJ&pg=PT7 | title=IBM Shows Its First 486, Claims Speed Records | magazine=InfoWorld | volume=11 | issue=26 | pages=1, 8 | via=Google Books}}{{rp|1}}{{cite magazine | last=Keefe | first=Patricia | date=October 9, 1989 | url=https://books.google.com/books?id=RCRN09BFuYUC&pg=PA39 | title=IBM 80486 upgrade leads the pack | magazine=Computerworld | volume=XXIII | issue=41 | pages=39, 50 | via=Google Books}}{{rp|39}} Less than a month later, however, a calculation bug was discovered in early batches of the 486 processor.{{cite magazine | last=Yoder | first=Stephen Kreider | date=October 27, 1989 | url=https://www.proquest.com/docview/398099426/ | title=Chip by Intel Contains Flaw in Calculating | newspaper=The Wall Street Journal | page=1 | via=ProQuest}} While the bug was relatively minor and rarely encountered in real-world applications, IBM halted further shipments of the 486/25 Power Platform until December 1989, after Intel had corrected the bug in further batches of 486 processors.{{cite magazine | last=March | first=Richard | date=October 30, 1989 | url=https://link.gale.com/apps/doc/A7819694/GPS?sid=wikipedia | title=Bug could delay 486 PCs | magazine=PC Week | volume=6 | issue=43 | page=8 | via=Gale}}{{cite news | last=Rudd | first=David C. | date=December 20, 1989 | url=https://www.proquest.com/docview/282663831/ | title=IBM unveils PS/2 based on i486 chip | newspaper=Chicago Tribune | page=3 | via=ProQuest}} In the interim, Apricot Computers released the VX FT, the world's first pre-built 486 computer, in early December 1989.{{cite magazine | author= | date=December 5, 1989 | url=https://link.gale.com/apps/doc/A7937600/GPS?sid=wikipedia | title=Minigrams | magazine=Computergram International | page=CGI12050016 | via=Gale}}{{cite magazine | last=Lavin | first=Paul | date=April 28, 1994 | url=https://link.gale.com/apps/doc/A15355986/GPS?sid=wikipedia | title=Down, but not out | magazine=Computer Weekly | page=42 | via=Gale}}{{efn|The first units of the VX FX were shipped in the first week of December 1989.}} Like the Model 70 386, the VX FT featured the Micro Channel architecture.{{cite magazine | last=Lavin | first=Paul | date=April 25, 1990 | url=https://link.gale.com/apps/doc/A8486840/GPS?sid=wikipedia | title=Racing to the top | magazine=PC User | page=131 | via=Gale}}

On December 19, 1989, IBM introduced the PS/2 Model 70 486, their first prebuilt computer system with the 486 processor. In essence, the Model 70 486 is identical to the Model 70 386, only with the 486/25 Power Platform preinstalled and with a different badge on the front of the case.{{cite news | last=Markoff | first=John | date=December 20, 1989 | url=https://www.proquest.com/docview/427472298/ | title=I.B.M. to Base a Computer On Powerful i486 Intel Chip | work=The New York Times | page=D8 | via=ProQuest}} Select units of the Model 70 486 were shipped to enterprises in the third week of December 1989, while volume shipment was slated for mid-January 1990.

All submodels of Model 70 have three Micro Channel expansion slots: two 32-bit slots and one 16-bit slot. The 16-bit slot features an extension for specific MCA graphics adapters such as the 8514/A.{{cite magazine | last=Poor | first=Alfred | date=February 14, 1989 | url=https://books.google.com/books?id=kggOZ4-YEKUC&pg=PA124 | title=25-MHz 386s: Fast, Expensive, and Worth It | magazine=PC Magazine | volume=8 | issue=3 | pages=94–153 | via=Google Books}}{{rp|139}}

The initial two entries in the Model 70 386 line were released in June 1988 and comprise the Model 70 386-E61, with a 386 processor clocked at 16 MHz, and the Model 70-121, with the same processor clocked at 20 MHz. The Model 70 386-E61 features 1 MB of RAM stock and a 60-MB ESDI hard disk drive. The Model 70-121 doubles the capacity of both the stock amount of RAM and the hard drive capacity. Both units may have their RAM expanded up to 16 MB total; they additionally sport a socket for a 387 floating point unit. The top-of-the-line Model 70 386-A21 was released later, in December 1988 (delayed a month due to FCC Class B emissions testing). IBM designed this submodel with a significantly different motherboard, with the 25-MHz Intel 386 processor residing on a daughtercard that plugs into a dedicated slot on the motherboard. This opposed to having the 386 processor plug into a QFP, as is the case with the initial two entries in the Model 70 386 line. Besides housing the 386 processor, the daughtercard also has a socket for 387 math coprocessor and 64 KB worth of 30-ns SRAM acting as cache, driven by an Intel 82385 cache controller. The Model 70-A21 featured the same 120-MB ESDI hard drive as the Model 70-121.{{cite magazine | last=Miller | first=Catherine D. | date=November 15, 1988 | url=https://books.google.com/books?id=yFs-_3jT-5kC&pg=PA112 | title=IBM PS/2 Model 70-E61 (16 MHz); IBM PS/2 Model 70-121 (20 MHz); IBM PS/2 Model 70-A21 (25 MHz) | magazine=PC Magazine | volume=7 | issue=19 | pages=110–117 | via=Google Books}}{{rp|112}}

In September 1989,{{cite magazine | author= | date=September 27, 1989 | url=https://link.gale.com/apps/doc/A7700600/GPS?sid=wikipedia | title=IBM touts Micro Channel features, tweaks PS/2s | magazine=Computergram International | page=CGI09270003 | via=Gale}} IBM introduced two new models of the Model 70 386. The first was the Model 70-061, a 20-MHz 386 unit with a 60-MB hard drive intended as a low-cost version of the Model 70-121; and the second was the Model 70-A61, a cost-reduced version of the Model 70 386-A21 (featuring the same 25-MHz 386 on a complex) with the same 60-MB hard drive.{{cite magazine | last=Sexton | first=Tara | date=October 9, 1989 | url=https://link.gale.com/apps/doc/A7742980/GPS?sid=wikipedia | title=IBM shaves PS/2 prices, adds disk, RAM options | magazine=PC Week | volume=6 | issue=40 | page=17 | via=Gale}} After a two-year gap with no new introductions, IBM announced the final four models in the Model 70 386 range in December 1991. These included the Model 70 386-A81, a 25-MHz unit with an 80-MB hard drive; the Model 70 386-A16, another 25-MHz unit with a 160-MB hard drive; the Model 70 386–081, a 20-MHz unit with an 80-MB hard drive; and the Model 70 386–161, another 20-MHz unit with a 160 MB hard drive. All four models came with 4 MB of RAM stock.{{cite magazine | author= | date=June 17, 1991 | url=https://link.gale.com/apps/doc/A10928320/GPS?sid=wikipedia | title=New PS/2 386SX models: feature faster performance, greater flexibility at lower prices | magazine=Edge | volume=2 | issue=56 | page=6 | via=Gale}} The PS/2 Model 70 386 was officially withdrawn by IBM in October 1992.{{cite magazine| author= | date=October 1992 | url=https://link.gale.com/apps/doc/A12862085/GPS?sid=wikipedia | title=Minigrams | magazine=Computergram International | page=CGI10290024 | via=Gale}}

The Model 70 486 was introduced in December 1989 in two variants: the Model 70 486-B21, with a 120-MB ESDI hard drive, and the Model 70 486-B61, with a 60-MB ESDI hard drive. Both ran the Intel 486 processor at 25 MHz and were essentially rebadged variants of the Model 70-121 and Model 70–061 with the 486/25 Power Platform preinstalled. IBM withdrew the Model 70 486 after less than two years on the market, in June 1991.{{cite magazine | author= | date=June 17, 1991 | url=https://link.gale.com/apps/doc/A10928316/GPS?sid=wikipedia | title=IBM Personal System/2: major announcement highlights | magazine=Edge | volume=2 | issue=56 | page=4 | via=Gale}}

{{Main|IBM PS/2 Model P70}}

File:IBM PS2 P70 8573-121 (0).jpg was a portable version of the PS/2 Model 70 386.]]

In May 1989, IBM released the PS/2 Model P70, a portable version of the PS/2 Model 70 386 that weighed {{convert|21|lb|kg}} (the same as the Model 70 386 desktop) and had a carrying handle. It featured a 20-MHz Intel 386 processor, 4 MB of RAM stock, and a flat-panel, amber-tined, monochrome gas plasma display. It was IBM's third attempt at a portable PC in the United States, after the market failures that were the Portable PC and the PC Convertible.{{cite magazine | last=Scannell | first=Ed | date=May 15, 1989 | url=https://books.google.com/books?id=UDoEAAAAMBAJ&pg=PA692 | title=IBM Takes Wraps Off Its Model 70 'To Go' | magazine=InfoWorld | volume=11 | issue=20 | pages=1, 101 | via=Google Books}}{{cite magazine | last=Kvitka | first=Andre | date=July 24, 1989 | url=https://books.google.com/books?id=hzAEAAAAMBAJ&pg=PT87 | title=IBM's Third Try at Portable Puts Handle on the Model 70 | magazine=InfoWorld | volume=11 | issue=30 | pages=76–77 | via=Google Books}}

The PS/2 Model 70 386 received positive reviews in the press. InfoWorld{{'s}} Stephen Satchell rated the Model 70 386-121 a "very good value" and assessed it as being faster than a PS/2 Model 80 with the same 20-MHz chip, despite the latter having a more complex construction and a considerably higher cost.{{cite magazine | last=Satchell | first=Stephen | date=August 1, 1988 | url=https://books.google.com/books?id=dDoEAAAAMBAJ&pg=PA56 | title=IBM PS/2 Model 70-121: Powerful Small-Footprint System Outpaces Model 80 | magazine=InfoWorld | volume=10 | issue=31 | pages=56–57 | via=Google Books}} Personal Computing{{'s}} Christopher O'Malley found the Model 70 386-A21 the fastest 25-MHz 386 machine compared to competitors from Compaq and Advanced Logic Research but criticized the limited avenues for upgrading the hard drive, on account of the more-proprietary ESDI interface that the PS/2 used.{{cite magazine | last=O'Malley | first=Christopher | author-link=Christopher O'Malley | date=September 1988 | url=https://www.proquest.com/docview/199453649/ | title=IBM's Model 70-A21: The Desktop Rocket | magazine=Personal Computing | volume=12 | issue=9 | pages=103–109 | via=ProQuest}}{{rp|107}} Multiple reviewers for InfoWorld rated the Model 70 386-A21 a good value for technical applications (particularly CAD/CAM) but poorly as a file server.{{cite magazine | last=Capen | first=Tracey | date=November 14, 1988 | url=https://books.google.com/books?id=wTsEAAAAMBAJ&pg=PT82 | title=Hot Rods | magazine=InfoWorld | volume= | issue= | pages=71–88 | via=Google Books}}{{cite magazine | last=Furger | first=Roberta | date=August 8, 1988 | url=https://books.google.com/books?id=cDoEAAAAMBAJ&pg=PA69 | title=PS/2 Model 70-A21: IBM 386 Burns Rubber at 25 MHz | magazine=InfoWorld | volume=10 | issue=32 | pages=69–70 | via=Google Books}}{{rp|69}} Bruce Brown in PC Magazine concluded: "IBM's PS/2 Model 70s combine small size, impressive modular design, and gobs of power in three pricey computers. You can't expand these computers much, but they come fully equipped anyway."{{cite magazine | last=Brown | first=Bruce | date=May 30, 1989 | url=https://books.google.com/books?id=HpsOD9ZeqScC&pg=PA212 | title=IBM Corp.: IBM PS/2 Model 70-E61; IBM PS/2 Model 70-121; IBM PS/2 Model 70-A21 | magazine=PC Magazine | volume=8 | issue=10 | pages=212–220 | via=Google Books}}

{{See also|List of IBM PS/2 models}}

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{{IBM personal computers}}

70

Category:Computer-related introductions in 1988