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    IBM 5170 led/key front panel

    When the AT was first released it was slightly cool to have one of those barrel keys on your keychain, at least at my workplace in San Diego for those lucky enough to be issued with an AT. Perhaps as a result they seem to very hard to find now. I used to work in the UK/EU auto industry, at...
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    XT 130W PSU 120V tp 240V conversion, is it possible?

    Yes, the same mid-rail is employed in the 63.5W 120VAC 5150 PS. When I converted mine to 230VAC I did not know that this point in the circuit would remain stable so used the 325V rail with a suitable voltage divider to supply the driver IC, at the expense of slightly-increased losses. The center...
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    5153 convergence and sharpness

    I've seen some sharp CGA images on these forums now and again while my 5153 doesn't look so good. I've tried adjusting the convergence and screen focus as best as I can, but I can see they need more work. Are there any other issues that might affect sharpness that should be corrected first...
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    Defective Seagate ST-4038 and ST-4051

    Just to update this old but still-relevant thread, I've had this same issue on an intermittent basis for a few years now, only on a cold start. Once it's been running it will restart normally even after sitting for a day or two. Since the inductor appeared fine I replaced the two nearby caps...
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    Mac Plus, error after installing 6.05 on HD, "System file may be damaged"

    The Mac Plus in my collection has 4MB ram and a recently-added external SCSI drive, a 170 MB Connor I think, non-"Apple" in any case. It had System 7 on it which had some issues booting with extensions applied, but otherwise didn't exhibit any other problems. The Apple HD SC Setup Utility...
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    Minibikes, anyone?

    I had a similar looking minibike in 1971 called "Cat 400" or some such but it didn't have the gas tank. The rear sprocket (which doubled as the disk brake) was almost as large as the rear tire so the chain would break frequently from hitting rocks, and I learned to bash the links back together...
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    Archiving QIC tapes

    I also used automotive high-pressure fuel hose to refurbish the roller on an Archive 2150S I acquired recently. Fortunately the belt was still good. To cut the rubber tube to length I pushed a portion over a drill bit, lubed it with dish soap and slit it with a box cutter while spinning on a...
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    How do you setup and have room for all your Classic Computers?

    Bought some new tables recently. With a small collection almost everything I have can be on display in my living room where they can be appreciated. Keyboards, spares and 4:3 LCD monitors stored in a spare room for testing, or reminiscing as required.
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    Sometimes I love exploding capacitors

    The beauty of living in a 230VAC country is that the next vintage EMI capacitor drama is just around the next corner. When my 5170 blew an X2 cap a few years back I was surprised to find there was no mains fuse inside the PS, so I added a pair while it was apart.
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    So what are you doing with your Indy/Indigo 2 these days?

    With its matching 19" monitor my Indy is on display along the back wall of my living room along with an O2 and a few few other computers. On a gloss-white table the colour stands out nicely. I'm more likely to spend screen time with the O2 because it has Alias Designer on it. But, what I like...
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    How do you setup and have room for all your Classic Computers?

    Hmm, the first signs of panic, which is proportional to the number of machines you have ... squared. Best to get it under control before it overwhelms you :o I only kept around a dozen pristine machines and half are on display in my living room, the rest stored in cupboards. I test them...
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    HP Apollo 9000 owners: ever found a sticky residue on the HIL keyboard cable?

    Everytime I unearth my 9000/735 to see if it still works I find the coiled-type keyboard cable is wet with an oily residue, no doubt leaching plasticizer from the vinyl. It's 25 years old now and seems have an endless supply of the oily stuff as I clean it just about every year and it just gets...
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    Questions about IBM 5150

    A 1" high scsi drive does fit nicely under the right-side floppy drive and is hardly noticeable.
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    Whoa! The 5170 front badge can be reoriented!?

    Because the switch goes on top. Section 3-125 of the Installation and Setup Manual covers this option. http://www.minuszerodegrees.net/manuals/IBM_5170_Installation_and_Setup_1502491_MAR84.pdf
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    IBM 5153 (CGA monitor) line voltage range

    Mine arrived with one corner of the aluminium frame bent. As I mentioned, I thought the quality was adequate, but certainly not as good as common Chinese brands such as Meanwell. However, I've never seen another PS with this particular output voltage, 110VDC. It seems that LED lighting...
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    IBM 5153 monitor not working!!!

    First, the HOT is Q403. The SAMs schematic has the voltages at each terminal of that and Q401. The power supply should be stable at 115 +/- 1 VDC. You can adjust it with an insulated trimpot screwdriver, but it must be under load, which it probably isn't right now. It's hard to diagnose this...
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    IBM 5153 monitor not working!!!

    CRT broken? Perhaps check that the filament is on. Look where the LED is wired, the secondary of the flyback, and note that it requires the HOT to be running. Is the PS output stable despite the monitor not working? If yes, have you checked through the troubleshooting information provided so...
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    XT 130W PSU 120V tp 240V conversion, is it possible?

    Yes, mR_Slug's wiring diagram is slightly misleading schematically, functional but not ideal if it's really wired that way. I just opened up my 1KVA NZ worksite transformer and the 110 VAC output is completely floating. I've run my US-sourced laser printer off it for the last decade. Home...
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    Selling really old (1994-95) Autodesk stuff on ebay - suicide?

    In any case, it's easy to install and only requires the CD, serial number and authorisation floppy. No phone call required, at least for c3. Mechanical Desktop brings back some memories as I purchased the first version to try out but did not stick with it. Meanwhile, I used v13 for fairly...
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    suggestions for period fitment of heat sink to ceramic 8087 40pin DIL

    Thermal resistance of the bond is dependant linearly on the thickness of the bonding/thermal material as well as its heat-conductive properties and area covered, so in theory even a dab of superglue would likely be very effective. But, using a non-flexible material such as superglue would not...
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