Talk:Therac-25

message: The (summary) reference lists 3 radiation-induced deaths (out of 6 accidents), while the article says 5 (of 6).
I won't change it myself because the reference may be dated but in that case this should perhaps be remarked upon@?
Now the article says 2 out of 6 in the introductory section and 3 in the end of the "Problem Description" section. Which one's correct? --CloudShaker (talk) 15:12, 7 December 2009 (UTC)
thread_title:  3 or 5 deaths? 

message: How does Assembly Language have anything to do with this? It's just a language, debugging isn't the point. The point is that it didn't have any hardware implementations as a fail-safe.
 - Klasanov  —Preceding unsigned comment added by 12.110.74.133 (talk) 17:48, 14 October 2007 (UTC)
thread_title:  Assembly Language? 

message: "The failure only occurred when a particular nonstandard sequence of keystrokes was entered on the VT-100 terminal which controlled the PDP-11 computer: an "X" to (erroneously) select 25,000 EV mode followed by "cursor up", "E" to (correctly) select 200 EV mode, then "Enter". This sequence of keystrokes was improbable, and so the problem did not occur very often and went unnoticed for a long time.[1]"
Shouldn't those energies be 25,000,000 eV and 5,000,000 eV, as opposed 25,000 EV and 200 EV, respectively?  —Preceding unsigned comment added by 141.154.36.251 (talk) 15:50, 1 July 2008 (UTC)
thread_title:  possible incorrectly stated energies for the 2 modes of operation? 

message: Were there any lawsuits involved, and how have the survivors gone on to live – any major ailments from the radiation?
Also, does anyone know where there are photos of the patient injuries or the Therac-25 machine itself? I feel these would add greatly to the article.  —Preceding unsigned comment added by 131.170.90.3 (talk) 02:44, 16 October 2008 (UTC)
replies: text: According to Nancy Leveson's comprehensive analysis of the entire Therac-25 incident (see the External Links section), there were a number of lawsuits filed against AECL, all settled out of court. 
Nat Hillary 16:58, 24 March 2010 (UTC)
thread_title: Aftermath of the Incident 

message: What does scanning mean when talking about radiotherapy? I had an idea that scanning meant sending some pulses/particles/something onto/through an object and getting some knowledge about the shape/content/material/constitution by looking at what is reflected or what gets through.
But it must mean something else here. The wiki article only talks of "scanner magnets" but the article by Leveson and Turner for example says something about that the machine could turn on the beam without scanning. 
Velle (talk) 19:11, 24 May 2010 (UTC)
thread_title:  Scanning 

message: While it's true that a software issue was at the root of the problem, I read elsewhere that operators walked away from the machine in operation. This contributed to the disbelief of there being a problem. Dlamblin (talk) 21:43, 10 August 2012 (UTC)
thread_title:  Operators 

message: Can someone add a pronunciation guide? Is "Therac" spoken with French inflection?  — Preceding unsigned comment added by 122.56.19.161 (talk) 09:06, 6 March 2013 (UTC)
thread_title:  Pronunciation 

message: Such incidents would not have been an issue in a single-use machine and unlike previous models, the Therac-25 relied on software rather than hardware safety interlocks. What happened was the operator using a keypad would select a particular mode. The machine would then start a programmed cycle and move plates into position. This normally could take up to a minute. Meanwhile, the operator then realizing his mistake would re-enter the correct mode. The machine continued to run the old cycle and ignored inputs from the keypad, but the display showed the new settings. The operator, not realizing this then switched on the machine and gave the patent the wrong dose of radiation.
"lack of synchronization between Datent, Ptime, and Magnet subroutines caused a change in data entry to remain undetected to the device"http://www.read.seas.harvard.edu/~kohler/class/05s-osp/goodrep/therac-mojibi.pdf  — Preceding unsigned comment added by Codeusirae (talk • contribs) 23:30, 29 October 2013 (UTC)
thread_title:  The software interlock could fail due to a race condition 

message: The article is missing the date the machine actually went into operation50.5.90.226 (talk) 14:29, 1 June 2015 (UTC)
replies: text: According to the Nancy Levenson source, a prototype was made in 1976 and a commercial version was available in late 1982, so I am using the latter date. I have added the information. Opencooper (talk) 00:04, 3 January 2016 (UTC)
thread_title:  When was the machine Made? 

message: The lede says "thousands of times greater than normal", the body says "approximately 100 times the intended dose of radiation" - which is accurate?  195.50.95.82 (talk) 19:26, 2 January 2016 (UTC)
replies: text: According to page 23 of this source by Nancy Leveson, typical radiation doses are in the 200-rad range, while a patient at Kennestone (Katie Yarborough) received dosage in the range of 15,000 to 20,000 rad.  Additionally, this source says that Ray Cox was supposed to receive 180 rads, but got 15,000 to 16,000 rads. That is a factor of 100 so I am changing the lead to match the body. Opencooper (talk) 23:54, 2 January 2016 (UTC)
thread_title:  Thousands vs. 100 

message: There is plenty study in eg. Military air operations that pilots use stimulants when there's nothing happening.
The error here was that the operation consisted of selecting a mode and starting the machine then leaving the room. A cow would have been a better operator than human for such task, especially given the lack of requirement for any ancilliary functions such as measuring the device functions as intended before patient uses it. 
I've been to ultrasound three times now and each operator of the ultrasound used significant force in pressuring the probe such that I had discomfort for several days. And each time nothing was found while the issue was definitely real and in the area probed. After looking at some ultrasound images i have to conclude ultrasound should not be human operated but only use through 3d scanner tomography that is possible to be operated by the patient. The way this would function is like the ipad fingerprint scanner. The computer informs the patient-operator when there is no longer new information arriving and asking patient to move the probe. Since it is a tomography, the results can also be interpreted without doctor assistance by computerized correlation to healthy reference data.  — Preceding unsigned comment added by 91.155.19.195 (talk) 00:55, 9 December 2018 (UTC)
thread_title:  half the issue was need for operator in a boring simple task 

message: The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion:
* 
Participate in the deletion discussion at the . —Community Tech bot (talk) 06:04, 9 May 2021 (UTC)
thread_title:  A Commons file used on this page or its Wikidata item has been nominated for deletion 

message: There are two potential sites hosting the Levison paper Safeware.  IEEE MIT is significant, prominent, but the version of the paper there isn't searchable, at least not in current Chrome browser.  The other hosting site is not prominent, but the search works on the .pdf, and perhaps the formatting is better.   If there were an "Alternate source" part to the Cite then that could be used on the 'safeware' cite.  Or we plump for one and forget the other.  Or we have both.  Opinions? . Chumpih t 22:33, 21 January 2022 (UTC)
replies: text:  You are correct. I downloaded both PDF files, and the PDF from MIT was again not searchable in Adobe Reader. I also parsed both PDF files through Beyond Compare, and you could see significant differences at a binary level.   I think the best option is to change the "safeware" citation to use the URL for the searchable PDF file. KD5TVI (talk) 23:40, 21 January 2022 (UTC)
replies: text: A reasonable compromise. Cool. Chumpih t 06:48, 22 January 2022 (UTC)
thread_title:  Two potential sources for the Levison ''safeware'' paper 

message: Regarding my edit of a couple of days ago, I'm not entirely sure whether this article should be in the past or present tense, per WP:WAS and its PDP-10 example, although I think some care should be taken to maintain consistency about it. I doubt anyone has a functioning PDP-10 anymore, or at least that anyone would try to use it in order to get their daily work done. Even the Enigma machine article uses present tense, although it has not been used since 1945 for any purpose other than as a historical curiosity. On the other hand, ENIAC, UNIVAC and Z4 (computer) are in the past tense, and even if someone had an operational Therac-25, it would probably be criminal to attempt to use it for its original intended purpose. (Ping @Chumpih, who is taking an interest in copyediting here.) —⁠ ⁠BarrelProof (talk) 16:02, 22 January 2022 (UTC)
replies: text: *(weak) Past tense seems most appropriate, as the article is currently written.  As  suggests, it's no longer a viable product.  That said, per WP:WAS, present tense should be preferred, so if there is a strong desire from others to bring this into the present, and consensus, that too would be fine. Chumpih t 22:26, 23 January 2022 (UTC)
thread_title:  Verb tense 

message: The operators in both ETCC cases were supposedly the same person, but the pronouns don't match ('she' in the first one, 'he' in the second one). 2001:14BA:9C49:9C00:39D9:C53B:83FC:3AE4 (talk) 09:47, 16 December 2023 (UTC)
thread_title:  East Texas Cancer Center operator 

message: Why is there a picture of this terminal here. I see no reference to it or what it relates to? Perhaps it needs a paragraph somewhere to explain it's relevance? Volatileacid (talk) 23:54, 19 December 2023 (UTC)
replies: text: There's a reference to VT-100 under the Therac-25#Root causes section (controlling PDP), so the image is OK to be on the page.  As for positioning, well that's a matter of taste and relevance, and it could arguably be improved ... by all means go ahead if you like. Chumpih t 07:09, 20 December 2023 (UTC)
thread_title:  Terminal DEC VT-100.