September 2018 - vcf-midatlantic

Re: [vcf-midatlantic] Reminder - Museum closed this weekend
by Jeffrey Brace 21 Sep '18

21 Sep '18

Yeah, I noticed the dead moths in there ;) On Fri, Sep 21, 2018 at 6:14 PM Tony Bogan via vcf-midatlantic < vcf-midatlantic(a)lists.vcfed.org> wrote: > > > > On Sep 21, 2018, at 6:12 PM, Evan Koblentz <evan(a)vcfed.org> wrote: > > > > > >>> VCF museum is closed this weekend so me, Jeff B., Corey, etc. can go > to Maker Faire. > >> I might be able to be docent Sunday afternoon. If I can I will go from > around 2 till 5 so we have a presence there. > >> > >> Tony > > > > Cool. If you go, then be sure to tell whomever's at the front desk. > > Roger that. I still need to close the door on the MOBIDIC so those > freeloaders stop coming in and dying in the case!! > Tony -- ======================================================= Jeff Brace =======================================================

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Reminder - Museum closed this weekend
by Evan Koblentz 21 Sep '18

21 Sep '18

VCF museum is closed this weekend so me, Jeff B., Corey, etc. can go to Maker Faire.

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Converting C64 from NTSC to PAL was: PAL C-64 on 1084-S?
by Herb Johnson 20 Sep '18

20 Sep '18

> I had asked many times how to convert a NSTC C64 to PAL and got many > different answers. I feel like I was sent down the wrong path. Jeff, I'm not continuing this discussion to annoy you, but to make a more general point in public. Also, maybe you'll be less frustrated if you see larger purpose in your process of resolving this conversion - you suggested one yourself, you learned the details of NTSC vs PAL and analog video. As I posted previously, solving problems isn't always about "a path" to a single solution. Not all problems are solved by doing one thing, but by doing many things. It's part of problem-solving to attempt many things. Each thing, either solves part of the problem, or aids your understanding toward a solution. And in the end, you don't just solve "a problem", you expand your knowledge and experiences. So Jeff, I think the path you followed, was mostly normal, not an effort to mislead you. In the larger discussion: some people work with vintage computers, because they enjoy "fixing things" or "getting things back into use". Sometimes repairs are a matter of necessity. And repair can be a learning opportunity. And it's fun to share repair experiences, which is what happened in this email discussion. When I start talking about "building character", that's when I've said too much. ;) Jeff, glad you've got PAL operation of your C64. Herb -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net

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Wanted: Mac IIci, IIcx
by Herb Johnson 20 Sep '18

20 Sep '18

I got an offer after my request for a IIci. Thanks. - Herb -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net

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PAL C-64 on 1084-S?
by Herb Johnson 19 Sep '18

19 Sep '18

Some of the discussion on this topic, suggests a lack of understanding of the differences between PAL and NTSC. A fundamental difference is: PAL uses 50Hz frame rates (vertical) and NTSC uses 60Hz. Why? It's AC power line frequency: the US uses 60Hz and the UK uses 50Hz. That has consequences. "Old" TV's in each country have analog circuits which produce vertical scan rates based on AC line frequency. The CRT video display, may see crawling horizontal "hum bars" from magnetically picking up AC line signals at one frequency while displaying another frequency. VCR's run motors and pull tapes, assuming one vertical frequency and not another. And some devices which claim PAL/NTSC compatibility, may more simply run PAL on 50Hz power and NTSC on 60Hz power. A video device that actually turns PAL signals and PAL frequencies, into NTSC signals and frequencies, would be a somewhat busy design. On the other hand, an LCD TV or monitor - which has no "hum bars" as it doesn't "scan" with a yoke coil, has little analog circuity, doesn't need to depend on the AC line for a frequency reference - can be set for PAL or NTSC and it's done. Also: if an old PAL computer is run from 60Hz AC power, it may use the AC line as a frequency source (to avoid those hum bars). It's then possible the "PAL" computer will try to produce 60Hz vertical video; but not necessarily PAL horizontal rates - depends on the design. I don't track these PAL/NTSC issues, or C-64's, but I'm aware of these consequences. That sets my expectations about fixing the problem - I don't expect "a cable" (wires only, not a dongle with a buried processor in it) to solve it. It will be interesting to read about the results on specific equipment. - Herb -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net

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Converting C64 from NTSC to PAL was: PAL C-64 on 1084-S?
by Herb Johnson 19 Sep '18

19 Sep '18

Jeffrey Brace wrote: >>From looking at the discussion it was apparent that it follows the old > story of the 6 blind men and the elephant. I was going to argue about this conclusion, but Bill Degnan posted first, and it's enough that he made the point. Jeff, if you had stated the problem clearly - and stated the work you did - someone might have suggested you recheck your work. Eventually that occurred to you, and you resolved the C-64 side of your problem. And, now that you identified your "monitor" - the Googles tells me it's a modern LED monitor, and therefore digital, and (as discussed) will likely display PAL or NTSC. So it wasn't the problem. Sometimes, Jeff, in solving a problem, one has to wander around it. Solutions don't always fall out from the obvious. And don't grouse if your friends can't read your mind or see what's on your workbench - by email. Meanwhile - today I was chatting "here" about AC power and frequency. Oddly enough, at the same time, I fried a couple of SCSI hard drives in testing and copying. Oddly relevant, because the apparent problem was **an intermittent connection on my AC power cord's neutral!!!** I don't know that - yet - but replacing the AC power cord will hopefully end these woes. I may have to replace my Mac computer, I'm not sure, I have to verify it wasn't the problem. And even more strange: while repairing a Mac Plus, the AC safety capacitor (that paper thingy) started to smoke! That's normal failure for them. Same thing happens in Apple II power supplies. Replaced it, and the supply is good again. Now I'm gonna kiss my AC power meter and apologize for talking behind its back. Herb "sparks" Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net

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Converting C64 from NTSC to PAL was: PAL C-64 on 1084-S?
by Jeffrey Brace 19 Sep '18

19 Sep '18

Changing the subject line to more accurately reflect the discussion. I solved my problem. It was a lot simpler than what the discussion indicated. I reason my C64 didn't work after my changes was that I had put the VIC-II chip in wrong. Two pins were sticking out. >From looking at the discussion it was apparent that it follows the old story of the 6 blind men and the elephant. Every was looking at a different part and was right, but didn't see the big picture and never really had any specific experience doing what I wanted to do (i.e. no one had actually done it!). For the last few years I asked different people questions, and didn't get anywhere. I realized that none of them had actually converted a C64 and were guessing. So I decided to look up the information myself and just do it. I thought that the simplest way was to just buy a PAL C64 and ship it here, but I ended up getting NTSC C64 because the guy had no idea what he was selling. I shipped it back and found an easier way by ordering the parts. I knew that there was an article from years ago that described what to do, but I had lost it. So I looked up a YouTube video: https://www.youtube.com/watch?v=aq2tlEr6_Ns&t=609s And looked at this article: http://biosrhythm.com/?p=1420 So I bought the proper PAL VIC-II chip, the proper crystal, and a piece of wire. I replaced the VIC-II chip: 6567 (NTSC) with 6569 (PAL), then the crystal 14 Mhz Crystal (NTSC) with the 17 Mhz (PAL), then found the part on the motherboard where I put a piece of wire to create a short. DONE! There was no need for step down converters, different power supplies or special monitors. The Samsung SyncMaster XL2370HD worked fine. I just had made a mistake when I inserted the VIC-II chip. Noticed it today, fixed it, and ran the demo. Now it seems that the demos want to run from a 1541 and not a 1571 or uIEC SD card unfortunately, so I have to go vintage. Also I used this video to VGA converter to send the signal from the C64 to the monitor: https://www.real.de/product/314543066/ If anyone wants help to convert it, I can help you. You need to match the proper VIC-II equivalent, there are three major versions of VIC-II chips, so that has to match because of the motherboard configuration. Now I have to find a particular type of audio cable RCA to headphone jack to get the audio working. Still have some other stuff to get ready for Maker Faire. -- ========================================= Jeff Brace Vice President Vintage Computer Federation

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Wanted: Mac IIci, IIcx
by Herb Johnson 19 Sep '18

19 Sep '18

Need immediately, Apple Macintosh IIci motherboard. Must be known working solid, well-tested. Available right now, to be shipped to me now in New Jersey. I'll consider a IIcx. Don't care or need other IIci/cx stuff like case RAM drives, might consider buying a system but why not just ship the mobo? Contact me directly if you have a IIci or IIcx. Thank you. hjohnson(a)retrotechnology.com Herb Johnson -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT retrotechnology DOT info

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Re: [vcf-midatlantic] PAL C-64 on 1084-S?
by Neil Cherry 19 Sep '18

19 Sep '18

On 09/19/2018 03:30 PM, Bill Dromgoole via vcf-midatlantic wrote: > A step down transformer only changes the voltage. > It does not affect the frequency. > You are still running at 60 Hz. To add to this, the computer hardware expects the TV to match the standard it's outputting. PAL - 625 scan lines, 25 Frames/s (50Hz) NTSC - 525 scan lines, 30 Frames/s (60Hz) Many computers send data to the TV while the scan line it written, while it goes to the next line, it's doing something else. The custom video chips are hard coded to these setings. While modern TVs may be able to handle this (some flatscreen TVs can handle PAL or NTSC) as it's just software. Older TVs were tuned for for the spec. If the PAL TV/Monitor were to get 60Hz it's 25 frames would be out of spec with the 60Hz. Grr, I'm afraid my explanation is a bit weak. But the 25 Frames/s and the 30 Frames/s rate would be out of sync with the change in frequency. The complexity of this has to do with the genius of goning from Black and White and handling color, in addition to the 50 and 60 Hz differences. A trip to the Sarnoff museum might be in order. At the moment I can't recall where I learned this but I'm pretty sure was related to my Atari 8 bit and Don Lancaster and his books. -- Linux Home Automation Neil Cherry ncherry(a)linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies

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Commodore 802 printer
by Herb Johnson 19 Sep '18

19 Sep '18

Someone contacted me with the following Commodore problem: > I have a 802 printer that stopped working. I use my C64 system a lot and wondered if you repair these, sell printers for the C64 or know of someone who repairs printers. The printer just stopped working ( the print head doesn’t move when you turn it on and the paper feed button is lit but does not advance the paper) I hope you can help. [I'm in] Pensacola, Fl. If someone wants to tackle this, I'll refer this person to you. I could suggest he join the VCFed-Mid list, but Florida is another physical locality, a local connection may be more practical if someone can suggest a Florida venue. Herb -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT retrotechnology DOT info

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