corpus.blog
56,966 blogs · 4,417,066 posts Claim your blog
Record · corpus.blog/posts/01a0be04-6473-709b-b284-18ffbba2073d

Intel's $475 million error: the silicon behind the Pentium division bug

Ken Shirriff Blog · published 28 December 2024

A record is what was published and who pointed at it. The text of the post is not held here: read it at the source, or at its Wayback capture.

Read the post at righto.com Wayback capture
2blogs citing
First cited
19 Dec 2025
Most recent
2 Mar 2026
Rank this month
not ranked
Links from this post
81
Words captured
11,370

Cited by

Blog
In the post
Date
Keet blog – research and modelling, with some relevance for society
Should you tell the client about software errors? Some notes on professionalism Read at the source ↗
2 Mar 2026
Andy Sloane's site
Pure Silicon Demo Coding: No CPU, No Memory, Just 4k Gates Read at the source ↗
19 Dec 2025

Links from this post

Link
Host
https://static.righto.com/images/pentium-fdiv/fdiv-bug-here.jpg
static.righto.com
https://davefaq.com/Opinions/Stupid/Pentium.html
davefaq.com
https://groups.google.com/g/comp.sys.intel/c/L1KDE1d_ZLA/m/7rydJksrVTcJ
groups.google.com
https://static.righto.com/images/pentium-fdiv/srt-diagram1.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/srt-diagram2.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/table-labeled.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pla-zoom.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pla-structure.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pla-labeled.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pla-silicon-right.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pla-lhs.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pla-top-labeled.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pla-entry-diagram.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pla-entry-diagram2.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/intervals.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/pd-table.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/adder-silicon.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/bounds2.jpg
static.righto.com
https://www.nytimes.com/1994/11/24/business/company-news-flaw-undermines-accuracy-of-pentium-chips.html
nytimes.com
https://static.righto.com/images/pentium-fdiv/new-pla.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/old-vs-new.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/comparison.jpg
static.righto.com
https://www.ardent-tool.com/CPU/Intel/fdiv/white11.pdf
ardent-tool.com
https://www.latimes.com/archives/la-xpm-1994-12-17-fi-9948-story.html
latimes.com
https://archive.org/details/bub_gb_mDsEAAAAMBAJ/page/n5/mode/1up?view=theater
archive.org
https://static.righto.com/images/pentium-fdiv/steppings.jpg
static.righto.com
https://commons.wikimedia.org/wiki/File:Intel_A80386-16_16_bit_SW_Only.jpg
commons.wikimedia.org
https://commons.wikimedia.org/wiki/File:Intel_A80386-16_%CE%A3%CE%A3.jpg
commons.wikimedia.org
https://creativecommons.org/licenses/by-sa/4.0/deed.en
creativecommons.org
https://support.microsoft.com/en-us/topic/kb4090007-intel-microcode-updates-3bdf784b-d4ad-d881-cfc1-658095b59638
support.microsoft.com
https://community.intel.com/t5/Processors/Microcode-0x129-Update-for-Intel-Core-13th-and-14th-Gen-Desktop/m-p/1622129
community.intel.com
https://static.righto.com/images/pentium-fdiv/pla-m2.jpg
static.righto.com
https://bsky.app/profile/trevorkevorson.bsky.social/post/3lcnv6h65hc26
bsky.app
https://websrv.cecs.uci.edu/~papers/mpr/MPR/EDITOR/0903ed.pdf
websrv.cecs.uci.edu
The Pentium as a Navajo weaving Read at the source ↗
righto.com
https://amzn.to/4gcXzVS
amzn.to
https://faculty.lynchburg.edu/~nicely/
faculty.lynchburg.edu
https://amzn.to/4gAD1pM
amzn.to
https://amzn.to/4gl8mx9
amzn.to
https://books.google.com/books?id=LbKf4ilmW8EC&pg=PA1
books.google.com
https://www.nytimes.com/1994/12/13/us/ibm-deals-blow-to-a-rival-as-it-suspends-pentium-sales.html
nytimes.com
http://lists.sigcis.org/pipermail/members-sigcis.org/2020-August/007088.html
lists.sigcis.org
https://groups.google.com/g/comp.sys.intel/c/xivOgqcUrS8/m/sODzYaJZzWMJ
groups.google.com
https://groups.google.com/g/aus.jokes/c/72sZitg-bTY/m/LCMN-LRD6egJ
groups.google.com
https://historyofcomputers.eu/hardware/the-pentium-fdiv-bug-when-math-became-a-stand-up-comedy-act/
historyofcomputers.eu
https://ardent-tool.com/CPU/docs/Intel/Pentium/spec_update/242480-022.pdf
ardent-tool.com
https://websrv.cecs.uci.edu/~papers/mpr/MPR/ARTICLES/090303.pdf
websrv.cecs.uci.edu
https://static.righto.com/images/pentium-fdiv/apology.jpg
static.righto.com
https://archive.org/details/FinancialTimes1994UKEnglish/Dec%2022%201994%2C%20Financial%20Times%2C%20%2322%2C%20UK%20%28en%29/page/n4/mode/1up
archive.org
https://daviddeley.com/pentbug/tim_coe.txt
daviddeley.com
https://people.cs.vt.edu/~naren/Courses/CS3414/assignments/pentium.pdf
people.cs.vt.edu
https://doi.org/10.1109/ARITH.1995.465365
doi.org
https://www.jstor.org/stable/2133004
jstor.org
https://web.archive.org/web/20060209005434/http://www.byte.com/art/9503/sec13/art1.htm
web.archive.org
http://link.springer.com/10.1007/3-540-59293-8_189
link.springer.com
http://boole.stanford.edu/pentium.html
boole.stanford.edu
https://righto.com/files/IBM_study.txt
righto.com
https://www.osti.gov/biblio/4157138
osti.gov
https://www.doi.org/10.1109/ARITH.1981.6159293
doi.org
http://www.bitsavers.org/components/weitek/dataSheets/4167_Floating-Point_Coprocessor_Jul89.pdf
bitsavers.org
https://www.ece.ucdavis.edu/~vojin/CLASSES/EPFL/Papers/4-Fandrianto_division_ARITH8.pdf
ece.ucdavis.edu
https://doi.org/10.1109/40.540
doi.org
https://patents.google.com/patent/US3702985A
patents.google.com
https://www.researchgate.net/publication/268005718_Coping_with_the_Complexity_of_Microprocessor_Design_at_Intel_-_A_CAD_History
researchgate.net
https://doi.org/10.1109/DAC.1982.1585495
doi.org
https://www.youtube.com/watch?v=LQcLhBZY12g&t=1700s
youtube.com
https://en.wikipedia.org/wiki/Espresso_heuristic_logic_minimizer
en.wikipedia.org
https://mathscinet.ams.org/mathscinet/relay-station?mr=1010233
mathscinet.ams.org
https://static.righto.com/images/pentium-fdiv/fractal.jpg
static.righto.com
https://doi.org/10.1109/MDT.1987.295165
doi.org
https://www.righto.com/2017/08/inside-fake-ram-chip-i-found-something.html
righto.com
https://static.righto.com/images/pentium-fdiv/bipolar.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/statsn-c-b-18.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/statsn-p-18.jpg
static.righto.com
https://static.righto.com/images/pentium-fdiv/statsn-c-p-merge.jpg
static.righto.com
https://link.springer.com/chapter/10.1007/3-540-59293-8_189
link.springer.com
https://youtu.be/E2MIpi8pIvY?t=1511
youtu.be
https://archive.org/details/1995-01-01_W5YI_Report/page/n8/mode/1up
archive.org
Undocumented 8086 instructions, explained by the microcode Read at the source ↗
righto.com
https://www.ele.uva.es/~jesman/BigSeti/ftp/Cajon_Desastre/MPR/111204.pdf
ele.uva.es
https://www.righto.com/2019/11/tros-how-ibm-mainframes-stored.html
righto.com