What retro computer activity did you get up to today?

Discussion in 'Retro & Arcade' started by adz, Jan 28, 2014.

  1. breech

    breech Member

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    Nice repairs Rugger - start up a YT channel! :thumbup:
    Whats the reason for halving the capacitance for the replacement polymers?
     
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  2. rugger

    rugger Member

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    Haha, long way away from being able to do that

    The low voltage side of the VRMs uses those huge capacitors not for shear bulk capacity, but to get a ESR low enough to move enough current at the high frequencies of the VRM switchers. ESR on polymer capacitors is much lower than the original electrolytics, so you can satisfy that filtering need though much less actual capacitance when using polymers.
     
    Last edited: Jun 14, 2021
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  3. gdjacobs

    gdjacobs Member

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    Indeed, capacitance is actually irrelevant for these. SMPS transistors tend to switch at 100khz or so which is right around the resonance point where capacitive and inductive reactance for standard electrolytic and polymer parts cancel out. Higher ESR translates into ripple voltage, so too large a value is obviously problematic. Some feedback configurations need a certain range of ESR in the loop to avoid instability, so ESR which is too low is generally to be avoided as well.
     
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  4. rugger

    rugger Member

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    Yep, motherboard VRM power phases from the the times where this matters seem to handle the switch to polymer just fine.

    Older motherboards you can typically find capacitors close to the original ESR specs with modern very low ESR caps (eg Panasonic FR, FS series), hence why it was not necessary to use polymers on the other 2 boards. You can often get away with polymer caps on these boards, but it is much more expensive and won't really improve things much if at all.

    Additionally, if you are recapping an AT or ATX power supply, you want to avoid the idea of polymodding completely. This is where you see feedback induced instability. Given that the capacitors for these power supplies are still being made, there is no reason not to replace for equivalent standard low esr electrolytic caps.
     
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  5. Pierre32

    Pierre32 Member

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    Just browsing the things, and ran across this flight sim setup - already sold pending pickup for $200. I can't quite get a read on the setup, as it looks to be a mix of new and old bits. What's powering it, and did it come with the sale? Either way someone's done well here. I'm really just curious about the owner and the backstory.

    upload_2021-6-15_15-37-16.png
     
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  6. Daft_Munt

    Daft_Munt Member

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    Just recovered my Steam account that I havent checked in for over 6 years (ok not the 10 year retro definition, but most of the games are). My pile of shame has grown once again. My PC is retro (Dell T3500).

    Edit: wtf a yahoo acccount
     
    Last edited: Jun 15, 2021
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  7. Pierre32

    Pierre32 Member

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    Checking in from the undisclosed post-apocalyptic location where dirty old treasures lie. (Yes I know the location was disclosed a moon or two ago, but let's leave that in the past where it won't hurt my job security :thumbup:)

    I can't touch this stuff (yet? ever?) but it was fun to get a closer look today. All the HP keyboards seem to be hybrid domes, but very weighty units, and if memory serves many had both PS/2 and RJ12 connections. I really hope I can rescue and rehome these, and I don't think there'd be much competition for them.

    No way of knowing what state the CRTs are in, but cosmetically they're surprisingly good. I've heard I'm not the only one eyeing them - there are folk elsewhere in the business who would like to put them back in service on site!

    Particularly enamoured with the ABB pizza boxes, which are some kind of Unix operator stations. They still hold value, and are probably none of my business. I also like that shelf full of delightful HP SCSI enclosures. They're marked as all being dead, which might bode well for a keen trash collector.
     

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  8. gdjacobs

    gdjacobs Member

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    Those ABB boxes appear to be some form of tweaked HP-UX machine. They have some extra real time control hardware for the discerning nuclear power plant operator.
     
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  9. Vanne

    Vanne Member

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    those multisync monitors look the goods, would love to have me one of them. (the clean looking white ones ) :D when do we find out when you can raid all this ...stuff.... ;)
     
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  10. Pierre32

    Pierre32 Member

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    At a guess, they'll want to start cleaning out that room some time in 2022.

    Remember that industrial PC I was talking about last year? It's from a different site. It was decommissioned a few months back, and is still waiting to be removed and brought to a workshop where I can have at it. The wheels turn slowly in these joints, but that gives you all the more time to express your interest, over and over, until people can't wait to hand it over so you'll shut up.
     
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  11. Vanne

    Vanne Member

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    Lol i love the way you think! :D
     
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  12. dirkmirk

    dirkmirk Member

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    [​IMG]

    Trying to get this old beast working, Tyan S2469 Thunder KX7 PRO (AMD 760MPX).

    Im getting 4 beeps on startup like counting to 4, "bip... bip... bip... bip", short beeps but spaced like counting to 4.

    I dont think its ram or video, maybe power supply? I can turn the machine off by holding the button down, im not sure what bios this thing uses as to troubleshoot the beep codes....

    Any advice would be appreciated.
     
  13. MUTMAN

    MUTMAN Member

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    isn't that board prone to USB issues ?
    I guess you can just try the usual checks;
    pull any USB keyboard or mouse out
    pull all the ram and just use one stick
    try a PCI vid card
    try a diff PSU
    pull the power and clear CMOS for 5 minutes
     
  14. dirkmirk

    dirkmirk Member

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    Maybe the ram is no good for this board:confused:?

    PC3200 rated memory (400mhz), the manual says it supports 200/266mhz memory, could be an issue?

    BUT If I remove the memory completely I get different error codes so not 100% its the memory?

    Got nothing plugged except a pci video card and ps2 keyboard.

    I cant work out if its a power supply issue either, some old ATX power supplies and according to the manual you just plug in the ATX 20 pin connector and another 4 pin plug on the 8 pin plug side....

    These weren't that hungry in terms of power (Athlon MP2800+).

    Just got me stumped whether it could be memory or power supply related, pretty this corsair memory is the right stuff (CMX512RE-3200LLPT) TWINX, I think its server memory but maybe the rated speed mucks up the compatibility with the board, I dont know.

    But the board also natively supports Barton CPUS which run at a higher fsb (333mhz) so the above quoted snippet should be incorrect( OR maybe the chipset doesn't allow faster memory).

    Gah, I never mucked around with server boards.
     
  15. Vanne

    Vanne Member

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    I've got this board myself, it's a phoenix bios...

    Check here for the beep codes under phoenix

    https://www.computerhope.com/beep.htm#phoenix


    Def ram related.

    Edit, this isn't a server board, it's a work station board.. huge diff..
     
    Last edited: Jun 20, 2021
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  16. Pierre32

    Pierre32 Member

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    Wonder if the first error code is incompatible memory, and the second one is no memory? You would hope that the 400mhz RAM just ran slower, but who knows. Definitely worth ruling that out with some correct spec RAM I reckon.
     
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  17. hutts24

    hutts24 Member

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    I haven't seen any laptop/desktop ever complain about having faster DDR in it, but I suppose there's a first time for everything. Wrong capacity can definitely be a problem, but in your case that is unlikely. Does the board need REGISTERED memory?

    Have you tried cleaning the RAM slots with a toothbrush and cleaning the RAM pins with a pencil eraser? The first suggestion may not do much, but the second suggestion has helped me many a time with RAM.
     
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  18. dirkmirk

    dirkmirk Member

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    These are the ram sticks I've tried all give the same 4 beeps so maybe not memory related....

    I was initially trying the platinum Corsair memory, I thought maybe I didn't have the right bios as their were releases to support the later MP cpus so found an old 1400 Thunderbird chip, no difference.

    I checked the cpu heatsink it had the original gunk from 2002 or so which look ineffective/crusty... Replaced that with fresh thermal paste again no difference.

    I suspected that if any memory was going to work, it would be the 256meg tall, crucial stick as that definitely looks the part for this board.

    So maybe I need a new power supply is all I can come up with:confused:?

    Not sure if any old desktop ATX power supply is up for the job or do I actually need to learn the power requirements for this thing....

    According to the manual IF I use a an ATX12V supply, you use 20 of the 24 pins on the main power connector and 4 on the 8 pin plug....
     
    Last edited: Jun 20, 2021
  19. mwd

    mwd Member

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    This one took a while to edit but it is finally live! Voodoo 5 vs Geforce 2


     
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  20. MUTMAN

    MUTMAN Member

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    :thumbup: for the sausage dog and the birdseye


    edit oh yer the content, that's good too :)
     
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