Talk:ZX81

message: As a former ZX81 owner, I think this is a pretty good article overall, but a couple of things did come to mind:
* I'm wary of appearing insular with this one, but there does seem to be a bit of an American slant in places, which seems odd as the ZX81 was primarily a British machine. Firstly, I think it would be much better if the main photo was of an actual ZX81 rather than a TS1000 (though the latter could certainly be retained to illustrate this variant), since although the outward differences are small they are there (brand name, "DELETE" key instead of the ZX81's "RUBOUT"). Secondly several peripheral prices are given in USD only, also odd for an article about a British machine.
:* You're right! A real ZX81 image is quite better, and I just happened to find one on Commons for once. I think the Timex image is better fit in the actuall Timex Sinclair 1000 article, so Im going to fix that soon. --AndersL 19:32, 29 November 2005 (UTC)
replies: text: The ZX81 was marketed in the U.S. Why do you say it is a "British machine"? Mirror Vax 23:04, 26 October 2005 (UTC)
replies: text: For exactly the same reason I consider the VIC-20, which was widely marketed in the UK, to be an American machine. After all, you can buy Jaguars in America, and the company is owned by Ford, but that doesn't stop a Jaguar being a British car. Besides, I don't have a problem with US prices being quoted for peripherals - but since this is an international encyclopedia, not a US one, I do have a problem with only US prices being quoted, and I was hoping someone would know the sterling prices and include them in this article. Loganberry (Talk) 15:52, 27 October 2005 (UTC)

text:  The machine was designed in Britain by a British company started by a particularly famous British entrepreneur.  I think that makes it pretty British :-)  Richard W.M. Jones 19:21, 27 October 2005 (UTC)

text: Very true, but you need to understand Britain in those days to understand why. The ZX81 was able to bring computing to the masses because it was designed down to a price (and was in fact a very elegant design in those terms, not a "poor" design at all). Britain had been struggling under a disastrous socialist/keynesian economic experiment since the war, and the masses of the people, teh proleteriat, were genuinely poor and could not afford the kind of computers (and other goods) americans could afford at the time. The middle class- in Britain, this translates generally to people who get an income from the government, such as bureaucrats, teachers, BBC employees and so on- got a computer especially designed for them a little later- a high spec, high cost machine with the BBC name attached. The rest of us had what we could afford, the ZX81 and then the ZX Spectrum. Cheap, shoddy british goods existed in order to be affordable to the cheap, shoddy british working class.82.71.30.178 (talk) 13:05, 2 December 2009 (UTC)
replies: text: A the time of its introduction - 1981 - the ZX81 had no competition at it's price range, all the other microcomputers available in the UK were far more expensive than the £69.95 of the Sinclair machine, or required kit-building and soldering skills as well as prior computer knowledge, these included the Acorn Atom, Tangerine Microtan 65, Research Machines 380Z, TRS-80, Video Genie, NASCOM, Atari 400 & 800, the Commodore PET, and the Apple II, the latter two and the RML 380Z costing serious money such that they were only found in businesses and institutions.  — Preceding unsigned comment added by 80.7.147.13 (talk) 20:29, 5 March 2014 (UTC)
thread_title:  A few thoughts... 

message: Does anybody have a tape cover of the 3D Monster Maze game, preferrably the original (J.K.Greye Software as opposed to the New Generation Software republishing)? It would look great for the infobox there. You're welcome to improve the article in any other way you can think of, too. TIA, BACbKA 22:08, 17 December 2005 (UTC)
replies: text: P.S. Just got a helping hand from the c.s.sinclair group, will upload the scan myself now. BACbKA 22:37, 17 December 2005 (UTC)
thread_title:  A call to ZX81 tape owners 

message: I have followed the 16KB RAM expansion pack image link, and it looks like the file suffered as follows:
# somebody posted it as a public-domain work to the English wikipedia
# subsequently it was moved over to commons
# thereafter the original en: upload was removed (since it was not a GFDL image, noone cared about the history)
# then the PD tag became obsolete, and an explicit reference to whoever uploaded it originally and why it had been public domain back then (own photo? another PD source?) is needed by the commons
Bottom line: this fine image is being threatened by the local copyright police any moment now :-) will the original uploader please step forward ASAP? Thanks, --BACbKA 12:01, 25 February 2006 (UTC)
thread_title:  Images at Sinclair ZX81 

message: There are a number of factual errors in this article.
1. The ZX81/TS1000 clock speed is 3.25MHz, not 3.5MHz as stated in the article (It uses a nominal 6.5MHz ceramic resonator, divided by 2).
2. The article states that the ZX81 contained a single 4118 (1k*8bit) RAM Chip.  Actually, a large proportion of the ZX81s made used a pair of 2114 (1k*4bit)RAM chips instead.  The PCB was designed so either could be mounted.
3. Further into the article, it states that in SLOW mode, user programs are only executed during the time the electron beam moves from the bottom to the top of the screen (The vertical retrace).  This is incorrect.  On the ZX81, in SLOW mode, user programs execute in the white top and bottom borders, not the vertical retrace.
4. In the section titled "Integrated Circuits", it "A15 is used for display purposes (see below), and the upper 32K memory area is therefore unusable for code execution, it can still be used to store data (such as BASIC programs) however."  It does not state though, that in the default configuration (i.e. without a RAM Pack >16k), the upper 32k contains a shadow of the lower 32k.  Hence, the previous sentence refering to 16/8 shadows is not strictly correct.
--MikeWynne 23:44, 25 April 2006 (UTC)
replies: text: Then edit and fix them! Edrigu 20:26, 26 April 2006 (UTC)
thread_title:  A few factual errors 

message: Wondereing if this is worth mentioning - if you touched the metallised paper whilst the zx printer was operating - under certain conditions (no rubber boots) - you got electricuted - I remember - it happened to me...HappyVR 12:29, 7 May 2006 (UTC)
replies: text: Ha ha.... I've never heard that one before, but it's pretty interesting. Still, unless there's a reputable online source confirming it, it counts as original research and shouldn't go in. Sorry :-( Fourohfour 12:22, 3 November 2006 (UTC)
thread_title: ZX printer - well built and safe to use...

message: As this page is one of the last on Merge since March 2006, I'm making a command decision. Sinclair 1500 was merged into Sinclair 1000, but since Sinclair 1000 now has a good bit of material, I'm NOT merging it to ZX81. If someone disagrees they can re-post the merge. Alba 19:41, 4 October 2006 (UTC)
replies: text: It seems okay to me now. The only objection I would have would be if more material were added and it ended up duplicating the ZX81 article (in other words, unique non-overlapping material is what counts). Anyway, that's not the case at present. Fourohfour 12:19, 3 November 2006 (UTC)
thread_title: Merge resolution

message: In the fast and slow section, it says that a 1-1000 for loop takes 19 seconds to execute, but it is unclear whether this is measured in fast or slow mode. Given the speed of contemporary Basics I'd guess it is slow mode. Can someone who knows please clarify the main article? Drhex (talk) 12:05, 29 April 2008 (UTC)
thread_title:  How slow? 

message: There's a good ref for this here. Letdorf (talk) 14:41, 25 November 2008 (UTC)
replies: text: That reference suggests that it was a ROM issue which was corrected at some point. If that's the case, the issue probably belongs in the "reception" section, as does the cover-up. Chris Cunningham (not at work) - talk 14:49, 25 November 2008 (UTC)
thread_title:  Square root bug 

message: I've begun to rework this article into an accessible form which follows our guidelines for article content. For now, this has necessitated removing about 50% of the content, which was an excessively detailed overview of the hardware to the point of reading like a professional runbook. I don't disagree that this stuff might have value, but when it is the main focus of the article (to the detriment of general details about the machine's impact in the market, its influence on later products, what it was used for and how it affected Sinclair) the article isn't doing its job. The material is in the page history if someone wants to take it and make a sub-article dealing with low-level technical details. Chris Cunningham (not at work) - talk 14:49, 25 November 2008 (UTC)
thread_title:  Significant reworking 

message: I am proposing to merge ZX Printer into this article.  There doesn't seem to be enough material on it to warrant its own article and has a Wikipedia:Notability issue due lack of sources.  --Macrowiz (talk) 15:38, 25 November 2008 (UTC)
replies: text: I don't think a merge is appropriate here. The printer worked with the Spectrum as well. If it's going to be merged anywhere, a good target is back into spark printer, from whence it came. I think it might be able to stand alone if good references are found though. Chris Cunningham (not at work) - talk 15:39, 25 November 2008 (UTC)
replies: text: I agree that spark printer is a better target since it worked w/ other computers.  --Macrowiz (talk) 15:46, 25 November 2008 (UTC)

text: This is still a stub article! The ZX Printer wasn't exclusive to the ZX81 and was a very common peripheral for ZX81 and ZX Spectrum users. Other Sinclair peripherals, like the ZX Interface 1 and ZX Interface 2 have had their own articles for some time now. The Spark printer article is about a particular printing technology; the ZX Printer is a notable example of a printer using this technology. IMHO, these topics can stand alone. Letdorf (talk) 15:54, 25 November 2008 (UTC)
replies: text:  The sources recently added are definitely an improvement and establish at least some notability in my view. Proposal withdrawn.    --Macrowiz (talk) 17:52, 25 November 2008 (UTC)
thread_title:  ZX Printer Merger proposal 

message: I can remember several adverts for ZX81 ROM swaps that improved speed.  One that I was interested in (but never had the courage to swap the ROM at the time) was a ROM with a FORTH 'operating system' on it.  The advert promised much faster operation and of course the FORTH language which tends to suite computers with few resources.
Would such unofficial add-ons or upgrades be appropriate for the ZX81 page?  —Preceding unsigned comment added by 86.179.55.186 (talk) 18:25, 14 November 2009 (UTC)
replies: text: Might be related to the Jupiter Ace which should probably be mentioned in the article. 69.111.195.157 (talk) 03:11, 19 June 2011 (UTC)
thread_title:  FORTH ROM 

message: I have nominated this article for consideration as a possible featured article - I hope to have it on the Wikipedia home page on 5 March 2011, the 30th anniversary of the ZX81's launch. Please leave your comments at Wikipedia:Featured article candidates/ZX81/archive1. Thank you. Prioryman (talk) 21:00, 10 January 2011 (UTC)
thread_title: Featured article nomination

message: I'm somewhat conflicted over this section - I think it's a good idea, yet the list prices are all in dollars, which goes against the UK English article, and most of the other listed machines are primarily American as well.
Does anybody else have any thoughts?   a_man_alone (talk) 12:54, 23 February 2011 (UTC)
replies: text: I added that section for two reasons. First, even in the UK, the ZX81's principal competitors were imported American machines, and priced in dollars. Sinclair Research itself cited American competitors (notably the TRS-80) as the ZX81's closest rivals. Second, although the article is written in UK English, we mustn't forget the fact that the US played a very big role in the ZX81's story - from Timex producing it to the hundreds of thousands of ZX81s sold in the US. The comparison table helps to show the relative merits of the ZX81 against its nearest competitors in the US market, which helps to explain why it had as big an impact as it did. Prioryman (talk) 23:24, 26 February 2011 (UTC)
replies: text: This is an interesting point, the currency issue. But I also have a problem with this section; Firstly, why is a phone listed for comparison rather then a more common computing device like a laptop or desktop model eg. something like the Asus EEE, a modern 'budget' device more comparable to this system. And why is a price listed for the Iphone that only seems to be relevant when signing a long term repayment contract with a US phone provider? Wouldn't an outright price for a computing device be more relevant for comparison. Furthermore, why is there no column for release dates? Isn't this an important tool for people comparing the specifications / costs?--Senor Freebie (talk) 03:20, 5 March 2011 (UTC)
replies: text: And why is the BBC Micro omitted?  —Preceding unsigned comment added by 81.174.149.61 (talk) 07:41, 11 March 2011 (UTC)
replies: text: The BBC Micro came after the ZX81. All of the computers listed were competitors of the ZX81 at the time of its launch - they were already on the market, and they were what Sinclair was trying to compete with when the ZX81 was designed. Prioryman (talk) 08:09, 11 March 2011 (UTC)
thread_title:  Comparisons between ZX81 and other computing devices 

message: The infobox claims "More than 1.5 million", citing the Sinclair website. But this interview states "the ZX81 which replaced it cost £69.95 and sold 250,000". Any ideas, anyone? The ZX81 was certainly less popular than the Spectrum, which claims "many millions of units". Any ideas, anyone? --Trevj (talk) 11:23, 23 May 2011 (UTC)
replies: text: The Guardian article is certainly wrong. WHSmith sold over 350,000 ZX81s in the UK alone in a single year. I would definitely be inclined to trust the manufacturer's website more than a newspaper's! Prioryman (talk) 14:24, 23 May 2011 (UTC)
replies: text: Pants. I suppose that means the ZX80 figure could be wrong too. It's not good when newspapers don't check their facts. --Trevj (talk) 14:51, 23 May 2011 (UTC)
replies: text: I'm afraid it's definitely wrong. The 50,000 unit figure refers to only the first year's sales. The ZX80 sold about 100,000 units in total. I'll add a source to that effect to the ZX80 article. Prioryman (talk) 15:43, 23 May 2011 (UTC)
replies: text:  --Trevj (talk) 18:52, 23 May 2011 (UTC)
thread_title:  Number of units sold 

message: Question: Do any reliable sources suggest a comparison between the iphone 4 and whatever computer/phones are compared in the disputed table? If not, then the table is original research and must be removed. See WP:RS and WP:OR.Wikifan12345 (talk) 23:23, 18 June 2011 (UTC)
replies: text: There were tons of published comparisons between the ZX81 and other 1970's-1980's computers at the time when those computers were being made, so there's not any issue about the comparison between the ZX81 and other computers of its era.  Including the iphone 4 is more anachronistic.  FWIW, nobody is disputing the factual accuracy of the comparison (it's just observation, not "research").  IMO it's ok to interpret NOR a bit loosely in a situation like that, which leaves an editorial question of whether the comparison helps the article.  I myself think the table is better off without the iphone 4, but was asking what others think.  As stated above, I wouldn't have minded as much if the "modern" device was something closer to the ZX81 in function and spirit. 69.111.195.157 (talk) 01:41, 19 June 2011 (UTC)

text: The cost of the iPhone is, in real terms, comparable to that of the ZX81 when it was launched. Strictly speaking I suppose the closest modern comparator to a ZX81 would be a cheap netbook, but are there any netbooks that are sufficiently iconic to serve as a modern comparison? Prioryman (talk) 22:53, 30 November 2011 (UTC)
replies: text: (Actually, after adjusting for inflation, the iPhone is still two and a half times more expensive.) You're right, a cheap netbook would be a better comparison, but the point is there should be no comparison to modern hardware. It makes no sense, as this article is about the ZX81, not the advancement of electronics since the 1980s. Muad (talk) 10:20, 2 December 2011 (UTC)
thread_title: Third Opinion

message: Should we add that bit about how young Aphex Twin created a sound with the ZX81?
Conkern65 (talk) 16:33, 2 December 2011 (UTC)
thread_title:  [[Aphex Twin]] Sound 

message: I came here to leave a note about ZX81: Small black box of computing desire in the news in 2011. But I see it's already included in #News reports. I know these are all valid refs but shouldn't they be either
#Included as inline citations; or
#Moved out of Article space (e.g. here on the Talk page?
-- Trevj (talk) 10:12, 6 February 2012 (UTC)
thread_title:  News reports 

message: The article claims that the NTSC version of the ZX81/TS100 computers had a different RF modulator and a different ULA. The modulator is indeed different (VHF instead of UHF) but is there any source for the claimed ULA difference? As there's no chroma and no sound, the only difference in the video signal is the number of lines (525 vs. 625) and that is controlled by firmware as this is an extreme bare-bones machine that does some ugly, kludgy things like SLOW mode and executing video memory as programme code. Some ZX81 kits in Canada (distributed at the time by Gladstone Electronics in Toronto for $C150 or $C200 assembled, in 1981 dollars) were the UK version with jumpers on the board configured to indicate NTSC 525-lines to the ULA but use the UK-style UHF RF modulator (there were differences in modulator pinout as the VHF NTSC modulator was switchable between two channels). The UK modulator will work on NTSC UHF 35 or so as there is no colour or sound - so PAL vs. NTSC is reduced to 625 vs. 525 line video as the sole remaining difference. 66.102.83.61 (talk) 17:17, 6 September 2012 (UTC)
thread_title:  NTSC version 

message: In tribute to 30 years of ZX81 Dr Beep tried coding a game in 1K RAM with hires. This ended in 2012 in 10 games together.
Never in history was a game coded in hires in just 1K of memory. 
This alone makes it part of the history of the ZX81.
In the meantime the Dr has coded 10 new hires games in just 1K.  — Preceding unsigned comment added by 82.171.174.50 (talk) 21:36, 29 August 2013 (UTC)
thread_title:  Why removal of ZX81 1K hires link? 

message: There is a statement in the "Features" section of the article that states "Early versions of the external RAM cartridge contained 15 kB of memory using an assortment of memory chips, while later versions contained 16 kB of chips but the lowest addressed kilobyte was disabled."
I have no references to this other than personal memory and the ZX81 circuit diagram and the referenced articles, but my ZX81 RAM pack, ordered in June 1981 and in my hands in July that year had 16kB of memory, and matched the description in the Personal Computer World review written by David Tebbutt referenced as [95] in the article. This was the first review published as far as I know, so must have been an early system. Additionally, my experience showed that rather than the bottom 1KB of the RAM pack being disabled, when it was plugged in, the RAM pack disabled the internal 1KB of memory by connecting the NOT RAM CS pin (pin 8) of the 2114 internal memory chips (or pins 18 and 20 of the 4118), which was on track 2A of the edge connector to the 5V line in the RAM pack. This arrangement can be seen in the scan of ZX81 circuit diagram and the scan of ZX81 16kB RAM pack circuit diagram (sorry, probably neither of these are sufficiently authorititive as a Wikipedia link).
Rather than just editing the article, I wanted to see whether anybody else had any comments on the change.  — Preceding unsigned comment added by Gatherp (talk • contribs) 17:52, 16 January 2014 (UTC)
thread_title:  15kB/16kB RAM packs 

message: The USA version of the ZX81 has indeed a channel selector switch on the bottom.  You can easily verify this for yourself by grabbing your USA-release ZX81 and flipping it over.
See http://www.zdnet.com/pictures/sinclair-zx81-teardown/6/ for a photo of the bottom of the USA version.
Thanks.  Sukiari (talk) 02:44, 3 January 2015 (UTC)
thread_title:  Moving part! 

message: Edited from FaceBook, plot only to 22 lines.
What = about 1kb RAM not working? mine OK.
3¼ or 3½ MHz?
USA 1s'd 2kb RAM.
Also USA 1s'd +1 resistor, which goes to pin of chip to give less top border, so as to fit display to screen, I think the chips =. PAL & NTSC = colour encoding, the fact that 1's 25, & other 30 pictures/2nd & N° of lines = what matters here.
86.145.116.78 (talk) 11:54, 18 May 2015 (UTC)
thread_title:  only 15kb RAM? 

message: In fact the very 1st Atari 800 Computers were shipped with 8 or 16 KB memory, expandable to 48 KB. After initial release, the 800 came standard with 48 KB memory. That= normally 48 (the comparable 400'd less).
Some time ref' to pixels = block graphics as on PET & ZX81, & not the N° of pixels used by full line of letters.
Pixels for VIC20 =@ start-up, it can do little better.
86.145.116.78 (talk) 12:20, 18 May 2015 (UTC)
thread_title:  List of other computers 

message: This entire article was using "kB" to indicate memory sizes, which is factually wrong, since kB is defined as 1000 bytes. Computers of this era used 1024-byte kilobytes, so all storage references have been corrected to "KB". Clayhalliwell (talk) 18:25, 21 July 2015 (UTC)
thread_title:  kB/KB 

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thread_title:  External links modified 

message: Why is this article introduced in the past-tense? Do none exist any longer? I was under the impression that so long as a product still exists in any form, we are to use the present-tense, like for the NES. — Supuhstar * — 05:09, 4 February 2018 (UTC)
replies: text: You're right; MOS:TENSE dictates present tense for everything except historical action. I've adjusted the lead. — Hugh (talk) 01:10, 5 March 2018 (UTC)
thread_title:  Past tense? 

message: Peripherals and software talks about a 5 MB HDD being on sale for the ZX81.
As per The Museum Of Hoaxes, this was a hoax article published in Byte on April Fool's Day 1982. The article clipping is shown, which reads:
"Responding to an obvious need of ZX81 owners for more data storage space, Hindsight Engineering has developed a 5-megabyte hard-disk system for the Sinclair ZX81. The system is available in either assembled or kit forms. The kit includes instructions for building your own clean room for kit assembly. A DOS will soon be available. For pricing information and a catalog of other products, write to Hindsight Engineering, POB 107.5, Peanutbutter, NH 03458."
I've never heard or seen of a HDD for the ZX81 in my long years knowing the machine. As this is a hoax, with no mention on the internet of a product ever having been seen, I'll remove this text. I don't think it's worth changing the text to talk about a hoax otherwise we could write about all sorts of things that also didn't happen. Better gone and the article slimmed down. ToaneeM (talk) 20:13, 10 August 2023 (UTC)
thread_title:  5 MB HDD peripheral was a hoax