August 2019 - vcf-midatlantic

Repair Workshops Jul, Aug, Sep?
by Jeffrey Brace 21 Aug '19

21 Aug '19

The next workshop is July 20 & 21. July 20 & 21 workshop signup: link: https://docs.google.com/spreadsheets/d/1WC20hnriY5alKGteeWoWq5jXT3ZOjzA6h-u… August 24 & 25 workshop signup: https://docs.google.com/spreadsheets/d/13Gmvr2ZEtEXouN0oB7Y_UtCRabbwhLTi4E_… We were thinking about doing another workshop in September. What do you think about September 28? -- ========================================= Jeff Brace Vice President Vintage Computer Federation

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[Off Topic] - Vintage computers and UPSes
by John Heritage 20 Aug '19

20 Aug '19

Hey folks, just curious For longevity of vintage computers that are hooked up and powered on semi-frequently; I assume any kind of UPS is better than none to try to reduce power spikes, or reduce PSU fatigue from brownouts. I was curious what folks recommendations or thoughts are here? I have a couple of old (~ 15+ year) UPSes that i'm debating replacing the batteries on, and one of them would be for plugging in some vintage hardware. Is there anything I should watch out for? Should I assume these are too old to effectively monitor/protect - or doesnt' that really matter? etc. Thanks! John

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[Off Topic] - Vintage computers and UPSes
by Herb Johnson 20 Aug '19

20 Aug '19

I think this subject is on-topic, because vintage computers suffer damage over time due to line-voltage and over-voltage. UPSs can't solve all those problems. But paying attention to the AC power line is important to collectors and users. Shorted tantalum capacitors on DC circuits are a known failure due to both time and over voltage. For example, Heath/Zenith H-89s and H-19s (computer and terminal) expect to operate at 110V AC.T he unregulated side of their 5V DC regulators have capacitors rated at a voltage just below the DC voltage produced - at 110V. When run at 120V or higher, the rated voltage is exceeded and the tantalums "blow". The fix is to replace the caps with higher-voltage devices, and/or reduce AC voltage. That solution won't be found with most UPS. A short-term solution is to use a Variac to reduce AC voltage. Long term, there's step-up/down transformers one can buy for the purpose. Technically-experienced people can make such devices. also: Thank you to Jason Perkins, for his post-link to an article on adjusting a UPS charging voltage. I was aware of this problem but not informed in detail. The article is informative, so thanks! http://www.jjoseph.org/notes/apc_smartups_battery_float_voltage Regards, Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net

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Re: [vcf-midatlantic] Pet with 9" screen
by mwillega 20 Aug '19

20 Aug '19

Other people's experience may be different, but in my experience, it is rare for a 1970’s era micro-computer schematic to completely match a board, as it was actually manufactured. Component differences and wiring differences are often found, even when comparing schematics that were drawn for a specific version board, to that same version board. You may want to determine how it came from the factory, in order to determine the best course of action for you. Regards, Mike W.

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Re: [vcf-midatlantic] AT&T Dataphone - Modem or "Service"?
by Jeffrey Jonas 20 Aug '19

20 Aug '19

Jeff (aka Bags): > ... There was a monitoring service offered as well > (wonders just how much you can monitor a line at 2400 baud) > under the same brand name. My guess: pre-divestiture phone lines were "voice grade": not guaranteed for FAX or data, thus requiring conditioning upon install and monitoring afterwards lest you get crosstalk, static and other interference. Neil Cherry: > I used to use Paradyne 740 muxes to break those out. Ah yes, modem sharing units. A strange kludge: some were "statistically multiplexed" to allow for different speeds, others were round-robin multiplexed, and others merely or-ed all the signals (I used those with software collision detection with per-packet ack-protocol!) > I also recall the Baby Bells delivering a special current loop line > for AP News service (I think it was dry). Those were fun, 28.8 baud. My local library had one of those teletypes clattering out the news. AT&T used to be "American Telephone and TELEGRAPH", thus the data lines! I'm unsure how they competed with Postal Telegraph and Western Union (my grandpa was a telegrapher). It was a sad day when AT&T decommissioned the last telegraph line. I remember the AT&T president saying that they'd remain "American Telephone and Telegraph" in honor of their heritage, but the following president undid that, making the name just "AT&T". Related to that: telegraph lines used to follow the railroad tracks, mostly for the railroad's internal use. Customer telegrams were sent when the lines were otherwise idle. Years later, right of way was a key part for competing phone companies: citing https://www.npr.org/2012/10/15/162963607/sprint-born-from-railroad-telephon… Sprint Born From Railroad, Telephone Businesses Melissa Block explores the long family history of the companies that comprise what became Sprint. It all began in Kansas in the late 19th century and came to include a long distance system created by the Southern Pacific Railroad Internal Network Telecommunications, or SPRINT. -- jeff jonas

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Re: [vcf-midatlantic] Welcome newbs!
by Jeffrey Brace 20 Aug '19

20 Aug '19

On Mon, Aug 19, 2019 at 4:18 PM Tony Bogan via vcf-midatlantic < vcf-midatlantic(a)lists.vcfed.org> wrote: > Best advice I can give you is to be more proactive and seek out > involvement instead of waiting to be asked. That, and perhaps reach out to > those that organize the various events (workshops, warehouse work, etc) > directly as opposed to a generic airing of perceived grievances on the main > list. In my experience Evan, Jeff, Corey and Dean are always ready to talk. > Laura, I'm sorry that you feel that you don't belong here. That is a terrible feeling. I hope that you can talk to Evan, Corey or myself privately and clarify what you are feeling. We do what we can to accommodate volunteers, but sometimes schedules don't line up. You are always welcome to come to a workshop, even if it is only to watch. There are many people that are new or not as savvy technically that will come and watch at the workshops before they try something themselves. There are always other members at the repair workshops that are helpful friendly and willing to teach someone else. You are also invited to Festivus which is December 7. I feel that our group is open to anyone and very tolerable of different quirks. Heck I've put up with Evan for 11 years and *everyone* knows what he's like ;) And by the way he's a dog person, but he's starting to see the light and know that cats are better than dogs. -- ========================================= Jeff Brace Vice President Vintage Computer Federation

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Re: [vcf-midatlantic] Welcome newbs!
by Evan Koblentz 19 Aug '19

19 Aug '19

> thinking i really really don’t belong here. i liked volunteering and learning but seems since there is another girl coming to things, I have been sorta cast aside. I have been told it’s scheduling conflicts, but my schedule issues are the same as always so.... I don't think this should be a list discussion, but since you brought it up, I will reply. Everyone knows that weekends (usually Saturdays), sometimes on Wednesdays, and very rarely other times are when I'm at the museum. For the last year-ish you made it clear that Saturdays/Wednesdays generally do not work for you. My schedule is less flexible as of last week due to my new job (conventional M-F/9-5 although I may sometimes get Wed. for working remotely). You also asked about working in the museum/warehouse solo. Access to the keys and the trust/responsibility of working there solo is reserved senior members who've proven themselves. Also most of the jobs require a lot of knowledge about computer history. There is absolutely no personal reason behind any of this, and all are welcome in our group ... even Corey (back at ya, dude)...

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Re: [vcf-midatlantic] Welcome newbs!
by laurakid 19 Aug '19

19 Aug '19

I would like to openly apologize for my previous comment to this thread. It was a knee-jerk reaction and innapropriate. It did however help me address some concerns I had with members of the group so I appreciate that. But going forward I will be more conscientious of the discussion. Sent from Yahoo Mail for iPhone On Monday, August 19, 2019, 3:35 PM, laurakid via vcf-midatlantic <vcf-midatlantic(a)lists.vcfed.org> wrote: That’s what I was told, but the reality is that I don’t get called on to volunteer at all anymore and used to be called on every other week or so. I don’t feel comfortable going to workshops when I haven’t even been involved. And my knowledge of vintage tech is not as great as my interest, so I rarely can participate in forums Sent from Yahoo Mail for iPhone On Monday, August 19, 2019, 3:31 PM, corey cohen via vcf-midatlantic <vcf-midatlantic(a)lists.vcfed.org> wrote: Laura, I think you might have misunderstood, sometimes when we ask for volunteers we are very specific on timing and that just may not have worked out for you in the past. VCF is very open to anyone, regardless of gender, orientation or choice of pet being a part of our community, this includes workshops, shows, volunteer work or participating in our online communities. Heck, we even let Evan be a part of the group and he's a cat person, so that shows you we accept anyone. LOL Cheers, Corey On Mon, Aug 19, 2019 at 12:30 PM Peter Fletcher via vcf-midatlantic < vcf-midatlantic(a)lists.vcfed.org> wrote: > Ouch. > > I’m only a dude that shows up for VCF East, but I hope the club isn’t > making anyone that would like to participate not feel welcome. > > > > On Aug 19, 2019, at 11:59 AM, laurakid via vcf-midatlantic < > vcf-midatlantic(a)lists.vcfed.org> wrote: > > > > > > From: laurakid <laurakid7(a)yahoo.com> > > Subject: Re: [vcf-midatlantic] Welcome newbs! > > Date: August 19, 2019 at 11:59:22 AM EDT > > To: vcf-midatlantic <vcf-midatlantic(a)lists.vcfed.org> > > > > > > thinking i really really don’t belong here. i liked volunteering and > learning but seems since there is another girl coming to things, I have > been sorta cast aside. I have been told it’s scheduling conflicts, but my > schedule issues are the same as always so.... > > > > > > Sent from Yahoo Mail for iPhone > > > > > > On Sunday, August 18, 2019, 9:47 PM, Jeffrey Brace via vcf-midatlantic < > vcf-midatlantic(a)lists.vcfed.org> wrote: > > > > Welcome new members! > > > > On Sun, Aug 18, 2019 at 9:11 PM Evan Koblentz via vcf-midatlantic < > > vcf-midatlantic(a)lists.vcfed.org> wrote: > > > >> There will be several new faces at the workshop next weekend, including > >> Nevell, Marc, Floyd, Doug P., Fred T., Maki, and Crawford G. (not to be > >> confused with Doug Crawford). > >> > >> -- > >> Evan Koblentz, executive director > >> Vintage Computer Federation > >> > >> www.vcfed.org > >> evan(a)vcfed.org > >> (646) 546-9999 > >> > >> VCF is a 501(c)(3) non-profit organization > >> > >> -- > > ========================================= > > Jeff Brace > > Vice President > > Vintage Computer Federation > > > > > > > > > > > >

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Re: [vcf-midatlantic] Pet with 9" screen
by Dave McGuire 19 Aug '19

19 Aug '19

If the OP does end up removing the CRT, I'd be interested in picking it up. My 9" pet has a failed flyback transformer, and I'd love to get it running again. -Dave -- Dave McGuire, AK4HZ New Kensington, PA

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Re: [vcf-midatlantic] Welcome newbs!
by Tony Bogan 19 Aug '19

19 Aug '19

“That’s what I was told, but the reality is that I don’t get called on to volunteer at all anymore and used to be called on every other week or so. “ Not everyone is appropriate for every job that needs doing. I also don’t always wait to be called but will reach out when I have available time and see if any help is needed. Sometimes it’s things I’m not “qualified” to help with!! (Not my area of expertise) “ I don’t feel comfortable going to workshops when I haven’t even been involved. And my knowledge of vintage tech is not as great as my interest, so I rarely can participate in forums.” That one I understand, but that’s also on you too. Involvement and amount of other participation has nothing to do with workshops. People come to workshops when they can and when they want to. Sometimes to fix stuff, sometimes to learn, sometimes (more often than not) to do both!! My knowledge of vintage tech was very limited when I started with VCF, especially because it relied on my memory from stuff I did 30-40 years earlier! (Not the most reliable for sure!) As time has passed I’ve learned tons, but my focus is still very limited compared to many others. My background is a user and I have no experience in electrical, programming, engineering, etc. What I know now (still extremely limited) has been from getting involved in workshops and learning on my own as well. Best advice I can give you is to be more proactive and seek out involvement instead of waiting to be asked. That, and perhaps reach out to those that organize the various events (workshops, warehouse work, etc) directly as opposed to a generic airing of perceived grievances on the main list. In my experience Evan, Jeff, Corey and Dean are always ready to talk. Just my .02 Tony Sent from my iPhone > On Aug 19, 2019, at 3:35 PM, laurakid via vcf-midatlantic <vcf-midatlantic(a)lists.vcfed.org> wrote: > > <mime-attachment>

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