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Re: interlace [was: NTSC TV demodulator ]

by CAREY SCHUG

This may have been covered before, VERY early in this tread. I think I tried a game on a flatscreen, and had issues. I don't know if it applies to the radio shack Color Computer, the interest of the original poster. many games and entry pcs with old style tv analog format, don't interlace, and tube TVs nearly all (except maybe a few late model high end ones?) are fine with that, but I seem to recall that most or all digital/flat screen can't deal with non-interlace. <pre>--Carey</pre>

1 month, 3 weeks

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Punchcards

by lukaskron＠posteo.de

Hello! This is my first message to this mailing list but I think this question is well suited for here. My name is Lukas and I am currently living in Germany and I am searching for punch cards preferable with logos/universities around the world. If someone still has some of such cards laying around I would love a message of your offer (off-list). Highly appreciated as I am collecting them. Kindly Lukas

1 month, 3 weeks

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Video/keyboard mono cable for Sun 386i

by Stefano Sanna

Hi. I recently bought a Sun Microsystems 386i and I discovered (too late...) that monitor and keyboard are connected to the same D15 connector on the back using a "Y" cable (I had experience with other Sun workstations, this was first contact with Intel-based hardware). Unfortunately, I have not such a cable neither I was able to find any info on the web about the pinout/wiring; probably it would be possible to create the cable from scratch (assuming that no other circuitry was inside the original Y cable). Moreover, I discovered that there is more than one option for video boards (mono and color): therefore, there is more than a single Y cable to connect monitor and keyboard. Looking at the official Sun's hardware list, I found this item: 630-1621 386i video/keyboard cable but it does not specify whether it is the mono or the color cable. In any case, it seems impossible to buy it on eBay or similar. Does anybody have some information on how to rebuild it? Thank you. -s

1 month, 3 weeks

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Re: Video/keyboard mono cable for Sun 386i

by Stefano Sanna

[sending message again, with attachment replaced by a link: https://www.mmcc.it/resources/misc/IMG_7975_video.JPG ] Thank you Richard! To use this cable, I need to replace my video card with a color one. Please, see attached picture of the connector I have on my 386i. I suppose that finding the video card is harder then the cable itself! :-) However, this cable could be a good start for trying to do some reverse engineering of the pinouts. Since the code I found is different, I supposed that we can assume 630-1621 is the code of monochrome screen/cable. BR. -s On 30/05/24 11:47, Richard wrote: > Oh and there is this > > > > s-l400.jpg > SUN Microsystems 530-1366-01 Monitor + Keyboard Cable 13W3 Mini Din8 > /A4 8 Pin > <https://www.ebay.com.au/itm/295331844851?mkcid=16&mkevt=1&mkrid=705-154756-…> > ebay.com.au > <https://www.ebay.com.au/itm/295331844851?mkcid=16&mkevt=1&mkrid=705-154756-…> > > <https://www.ebay.com.au/itm/295331844851?mkcid=16&mkevt=1&mkrid=705-154756-…> > Which looks right > Sent from my iPhone > >> On 30 May 2024, at 19:07, Stefano Sanna via cctalk >> <cctalk(a)classiccmp.org> wrote: >> >> Hi. >> >> I recently bought a Sun Microsystems 386i and I discovered (too >> late...) that monitor and keyboard are connected to the same D15 >> connector on the back using a "Y" cable (I had experience with other >> Sun workstations, this was first contact with Intel-based hardware). >> >> Unfortunately, I have not such a cable neither I was able to find any >> info on the web about the pinout/wiring; probably it would be >> possible to create the cable from scratch (assuming that no other >> circuitry was inside the original Y cable). Moreover, I discovered >> that there is more than one option for video boards (mono and color): >> therefore, there is more than a single Y cable to connect monitor and >> keyboard. >> >> Looking at the official Sun's hardware list, I found this item: >> >> 630-1621 386i video/keyboard cable >> >> but it does not specify whether it is the mono or the color cable. In >> any case, it seems impossible to buy it on eBay or similar. >> >> Does anybody have some information on how to rebuild it? >> >> Thank you. >> -s

1 month, 3 weeks

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Re: Pragmatically [was: Experience using an Altair 8800 ("Personal computer" from 70s)]

by CAREY SCHUG

> On 05/28/2024 1:05 PM CDT Sellam Abraham <sellam.ismail(a)gmail.com> wrote: > > What if a corporation in 1970 purchased an IBM 360 for each of their employees for their individual personal use? Now what? > > Sellam > 1. I don't believe ANYBODY could purchase a 360. You had to lease them. 2. do you know of such a company? (with a significant number of employees, not a lone entrepreneur). I figure asking means that maybe you do. and since I believe no 360 but maybe the model 20 (not a real 360) or the model 22 would plug into household power it seems unlikely unless a tax dodge. 3. if it was one purchase order, it sounds like ONE for the personal computer tally, vs thousands for the not-personal tally. Remember we still need to have enough computers to be 10% (or negotiated percentage) of the total produced. One exception does not change everything. ----------------------- I should have repeated my other suggestion. Only computers NOT depreciated/expensed count as personal. If depreciated, it is a business computer for business purposes. to summarize any or all of the following: -- if depreciated or expensed (reducing income) it is business, otherwise personal. ** --10% of purchases (a lot counts as ONE purchase, including "100-200 per month for 3 years") must be out of household funds (per income tax filings) for and used for household education, not for earning claimed income. --by some criteria, be able to plug into private home power for a reasonable subset of the population. ** There could be tax reasons/dodges (not saying they are legal): (1) a small business could expense them immediately (vs depreciate over years) by titling them in employees' or families' names, (2) a private individual could depreciate even though not actually doing any significant amount of income earning work on them (3) would have been expensed/depreciated but not enough income to be of any advantage, (4) probably many others, ask a shady tax lawyer. --Carey

1 month, 3 weeks

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Re: terminology [was: First Personal Computer]

by John

From: ben <bfranchuk(a)jetnet.ab.ca> To: cctalk(a)classiccmp.org Subject: [cctalk] Re: terminology [was: First Personal Computer] > The third thing is a real OS. Nobody has one, as a personal computer. > CP/M and MSDOS does not handle IRQ's. Unix for the PDP-11 is real > operating system but not personal as it requires a admin,and a > swapping media. This an auld refrain among *nix partisans of the ESR type, but I've yet to hear someone offer up a real defense of it. Even putting aside what "handles IRQs" means here (yes, strictly speaking the IRQs on the IBM PC are handled by the BIOS and/or add-on drivers/utilties, but DOS most certainly makes use of the facilities provided,) why does that make it "not a real OS?" What does PDP-11 Unix provide which MS-DOS doesn't to make one "real" and the other not? Certainly, nothing about a single-tasking single-user text-based environment *requires* interrupt-based I/O, even if it may smooth out performance in some aspects. And there's little if any call for a security system that'd require an administrator account in such a model; if one user "owns" the machine, whatever they decide to do to it can be Considered Legitimate. Virtual-memory capability may certainly enable the user to do more than they'd otherwise be able to, but it's hard to make an argument for it as a *requirement;* even *nix can run without swap, and in point of fact DOS can be support virtual memory with a protected-mode extender. Or is it multi-tasking capability itself that makes the difference? Can't see why that should be the case; it's definitely convenient, but as one person can only be doing so much at any given time, it's also hard to see that as a *requirement.* So what, then, consitutes a Real Operating System, and why?

1 month, 3 weeks

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Re: First Personal Computer

by Smith, Wayne

I did a bit of searching on Google Books and there is an article from the June 28, 1972 issue of ComputerWorld that states "Ever since Hitachi introduce the Hitac 10 as a 'personal computer' in 1969, not only the regular computer manufacturers but electric appliance, calculator, watchmakers, communications and software companies, and even textile manufacturers, have plunged into the minigame." While they are talking about minis, what this does show is that the term "personal computer" was used prior to the advent of the Altair.

1 month, 3 weeks

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Help? Programming SCM90448 EPROMs

by emanuel stiebler

Hi all, anybody in the US could program some SCM90448 EPROMs for me? None of my programmers I have here, can do it. Some old, trusty DATA I/O ??? Thanks!

1 month, 4 weeks

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Re: First Personal Computer

by Christian Corti

[Forwarded from Martin Bishop as some anti spam mechanism rejects his posts] -----Original Message----- From: Martin Bishop Sent: 27 May 2024 23:57 To: 'General Discussion: On-Topic and Off-Topic Posts' <cctalk(a)classiccmp.org> Subject: RE: [cctalk] Re: First Personal Computer In the UK the domestic wiring norm is 13A plugs on a 32A ring at 230V : ~3 kW. https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#BS_1363_(Type_G) My domestic computer supplies are wired out on BS4343 (Euro / Industrial) plugs and sockets 16A on a 32A ring at 230V : 3k68 VA. https://www.edwardes.co.uk/categories/industrial-euro-plugs---sockets-bs4343 IMHO, based on measurement, the BS4343 outlets have much better earth conductivity than the BS1361 Gs I want the protective devices to trip, not an electrical experience - other folk's installations provided that Tshirt Martin -----Original Message----- From: Christian Corti via cctalk [mailto:cctalk@classiccmp.org] Sent: 27 May 2024 16:53 To: Don R. <cctalk(a)classiccmp.org> Cc: Christian Corti <cc(a)informatik.uni-stuttgart.de> Subject: [cctalk] Re: First Personal Computer > 16amps where? In Europe? At least in Germany 16 amps is standard. The Schuko outlets and plugs are rated for this current. As an example, the fuse box in my appartment is splitting up the three input phases (63A each) from the main distribution panel to 3x 3 circuits/16A each. Christian

1 month, 4 weeks

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Re: ANITA ((was: Experience using an Altair 8800 ("Personal computer" from 70s)

by Rick Bensene

Christian Corti wrote: > The Anita electronic desktop calculators are a perfect example for the usage of > selenium rectifiers in logic gates. ..and anyone who has restored one knows that the vast majority of the back-to-back selenium diode packages have to be replaced with something else as they no longer function properly. Ambient moisture kills Selenium as a semiconductor, and even though these devices were packaged to avoid that to some degree, after 60 years, stuff happens. Many restorers resort to de-soldering the dual-diode packages from the circuit boards, hollowing out the package (removing the Selenium rectifiers and the potting material used) and installing back-to-back conventional Silicon diodes that are rated for the appropriate voltages involved in these machines, potting the diodes in place with some kind of material (epoxy?), and re-soldering the package to the circuit board. These calculators used gas-discharge active logic elements (e.g., thyratrons and dekatrons) and used (relatively speaking) high voltages for their logic levels. Fortunately, these gas-discharge devices seem to fare quite well with time, and though some do fail due to atomic-level outgassing or simple breakage, the majority of them work just as well the day the machine came off the assembly line. Such practice with the Selenium rectifier modules makes the calculator look original if done carefully, and allows it to function when operation was impossible with the original devices. It is an extremely tedious and time-consuming process, as there are a great many of these devices used in the first-generation Sumlock/ANITA calculators. I applaud anyone with the courage and patience to perform such surgery on these unusual artifacts. Fortunately, the circuit boards are quite robustly made, and the traces are large and well adhered to the base material of the circuit board (unlike many later calculators), making such an operation feasible. I am not brave enough to try this with the museum's ANITA Mk8. After 25+ years of owning this artifact, I have not even tried to apply power to it in any fashion, and probably never will. It is one of the very few calculators in the museum that is probably not in operational condition, as I strive for all of the exhibited machines to be operable and available for visitors to the physical museum to play with if they desire. I'm content to leave it as it is for a display machine, as it is in very nice original condition. Interesting to note that many ANITA Mk8 machines have a single transistor in them. It's in the power supply. The designers were comfortable enough using these relatively fussy gas-discharge logic devices as digital devices(they had developed machines like Colossus using this technology considerably before transistors were a thing, so there was certainly historical precedent), but the transistor was just fine for an analog purpose in the power supply. Boy, did they ever get it backwards (in terms of the longevity of gas-discharge logic elements in electronic calculators and what became the ubiquitous use to transistors)! Not intended at all to slight the accomplishment of Sumlock Comptometer in the development of these calculators. They set the stage for the explosion of what was to become a many hundreds of million dollar market by the end of the decade, not to mention setting the electronic calculator up to be the driving force behind integrated circuit development for a consumer-oriented device. ICs before their development for use in calculators were only for big mainframe computers, military weapons systems, the spooks at places like the NSA, and the space program. For that matter, the ANITA Mk7/8 could be said to be the progenitors for the development of the CPU on a chip, and by extension, the personal computer. Notice I didn't specify any machine, or say "first". Slippery slope there. Rick Bensene The Old Calculator Museum https://oldcalculatormuseum.com

1 month, 4 weeks

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