Saturday, February 3, 2024

Thou shalt follow these Vintage Computing Commandments

Since vintage computing is supposed to be a spiritual experience, I point out that today, February 3, 2024, the Torah reading for this week is the Ten Commandments. Regardless of your religious tradition or lack thereof, I think we can all agree on these.

  1. Thou shalt check voltage and polarity on new-to-thee power supplies, or thy machines shall be smote and release smoke. This is sometimes very hard to judge without a load, but they should be somewhere in the ballpark, verily, and you should get in the habit of checking any new power supply before using it with your irreplaceable collection. I've been collecting some of the wallwart specifications for early consoles, including the listed values on the casing and the actual nominal values I got with my multimeter.

  2. Thou shalt remove batteries when placing items in storage, or thou will surely go to hell with them. For example, the person who improperly stored this particular Apple prototype is certainly going to hell for ruining an irreplaceable artifact. And not just lithium batteries: any battery. AAs leak too. On my pinball machines the battery holders to maintain the high scores have been relocated to the bottom of the board instead of the top so that gravity won't drag the batteries' corrosive contents all over it.

  3. Thou shalt support the lower half of laptop screens and other hinged computers when opening them, lest they break like an MD5 hash. This is becoming a bigger and bigger problem as plastics age, especially because on some designs the plastic display backs were either load-bearing and/or had metal screw races embedded in them which can tear out. The typical symptom is that the bottom of the bezel cracks when you open it and by then it's too late. Mid-1990s Apple PowerBooks are notorious for this (see our restorations of the PowerBook 1400 and PowerBook Duo 2300c) but it's also a significant problem for many PC laptops of around the same age. Depending on your skill and the location of the attachments it may be possible to reinforce the back of the top display, potentially using some sort of compatible high strength epoxy (JBWeld solves a lot of problems), but this will necessarily fuse some portions of the display together and may cause failures at other points which are now comparatively weaker. In the meantime, I've found the best way to open them is to put your palms on the bottom half of the display back near the hinges as you swing the laptop open, supporting where the attachment sites to the hinges are, so that you prevent the action of opening the hinges from putting further strain on those attachments.

    A similar phenomenon occurs with clamshell pocket computers such as the Casio FX-780P/790P and their American rebadges as the Tandy PC-5 and PC-6. These machines often put substantial strain on the plastic cover directly over the hinge pin, and when this cover breaks, the hinge pin will pop out and potentially damage the wide ribbon cable between the two halves. Once this hinge cover fractures, I haven't seen a good way to repair them because the hinge pin must be able to rotate freely — you can't just fuse the whole thing together. As a result, eBay is littered with used examples where the hinges are now totally shot. You may be able to prevent it from happening if you directly place pressure on both hinge covers with your fingers as you open the case, or put a strong strip of tape between the halves and over the hinges to reinforce the cover and shift the points of strain.

  4. Thou shalt use a head protector or dud 5.25" floppy disk when moving floppy drives, so that they might not clatter, crash or misalign. Yeah, remember those white cardboard head protectors you threw away thinking you'd never use them again? Good times, huh? While a piece of smooth paperboard or cardboard cut to size with a central hole can often suffice, you could potentially damage or warp the spindle if you cut it wrong and force the drive door closed over it, so the safest approach if you don't have a properly made head protector anymore is just to use a physically intact floppy disk that you know doesn't work. (Careful of labels, though.) You don't need to do this for 3.5" drives.

  5. Thou shalt not wrap the power cord around any plastic case, lest the stigmata they cause be grievous. I've mourned otherwise pristine machines with ugly gouges in their cases that neatly fit where the power cord had been. This is due to the plasticizers in the cord which will also plasticize the hard plastic shell of the computer itself — and you don't want that plasticized. Store the cord either completely separately from the main unit or, if it cannot be detached, let it dangle in the box or put a bag over it so it doesn't contact the computer's case.

  6. Thou shalt keep the box and paperwork if thou can, so that future generations may appreciate the context. Besides obviously making the collection more complete, we're all nerds here and computing is a cultural experience. Price tags are great comparison pieces, sales receipts and business cards are themselves historical artifacts, often referencing people and places long since departed, and who'll remember the warranty cards if nobody saves them? Sometimes unexpected letters and correspondence can be clues about what a particular computer or peripheral was used for, and those pack-in product circulars are often useful ways of finding out about what other bits you should have on your list. Plus, if nothing else, the device's original packaging is usually a safe place to store it.

  7. Thou shalt not say "recap!" every time someone else says their computer is broken. In general, this is lazy diagnosis. It's by no means limited to classic computers; classic pinball has the same kind of kneejerk repair response, but it's no less obnoxious. There are definitely systems that are infamously prone to bad capacitors — virtually every 68030 Macintosh and Macs of the same era, such as the Macintosh Portable, will require recapping if they're still on their original set — and some that are at higher risk, such as those from the capacitor plague in the early 2000s. On the other hand, many other machines are just as likely to have problems in other components instead, if not more so. Electrolytic capacitors don't have an infinite service lifetime, but virtually all of my 1970s and 1980s systems are still running fine on their original caps, and those that did crap out invariably experienced a failure in something else. Trying to fix what turns out not to be broke just runs the risk of you ruining something else. Test things first before unthinkingly replacing them.

  8. Thou shalt figure out what thou willst do with thine collection upon thy passing, or all thy hard work will be lost in an estate sale or something. It is possible, and for some folks even probable, that a well-maintained collection will outlive you. Don't let your hard work be lost. We've all had pipe dreams at some time in our collector lives about opening up our own computer museums. For most of us, this dream will never come true, and even the people foolish or bloodyminded enough to qualify for a 501(c)(3) will discover the hard way that museums don't run themselves. Instead, consider donating particularly notable items to those reputable museums that do exist, and making arrangements in either your estate or when you downsize for the next generation of collectors to let your legacy live on with them. Instead of charging money to sell your pieces, have interested parties write you an essay or something about why they'll be a good home — and then make sure they keep a printout with it (as it is written in the Sixth Commandment). Consignment tables at vintage festivals are also good options, or just post a "come and get it" somewhere like the VCF Forums: you're guaranteed to get interest from somebody, because the glory days of finding Atari 800s at swap meets have long gone the way of the Canaanites.

  9. Thou shalt keep thy wife, or thy husband, or thy partner, or anyone else thou cohabits with, we judgeth not, happy and limit the number of rooms thou occupyest. I made a rule I would keep my systems to two rooms and I've (mostly) followed it. The overflow goes in storage units, not into other rooms (mostly). Additionally, it was helpful that my wife knew beforehand what she was getting into (mostly).

  10. Thou shalt not make vintage computing your G-d.


  1. I've read you making similar comments about recapping before, but I often have issues troubleshooting caps in circuit to make sure they aren't the problem. Any tips on testing them first/ruling them out?

    1. Usually I just do it with a multimeter; any good one will have a decent capacitance mode. This doesn't necessarily mean the cap is good if I get the right value, but it does mean I should be checking other stuff.

    2. Capacitance mode on a multimeter won't work reliably to measure capacitors while they are in circuit. A better method is to use an ESR meter, whose measurements are more accurate on an in-circuit component. Googling "DIY ESR meter" shows several methods to make one's own device if you don't want to spend the $$$.


Comments are subject to moderation. Be nice.

See more of my general vintage computing projects,
mostly microcomputers, 6502, PalmOS, 68K/Power Mac
and Unix workstations, but that's not all. Be kind, REWIND and PLAY.

Buy Me a Coffee at

Old VCR is advertisement- and donation-funded, and what I get
goes to maintaining the hardware here at Floodgap.
I don't drink coffee, but the Mr Pibb doesn't buy itself. :-)
Thanks for reading. -- Cameron Kaiser