Daily Apple

This morning I dug out my other two power bricks.  I was going to test them with my simple test.

One was still wrapped up in bubble wrap, from when I got it.  I plugged in the other one and checked the initial temperature by touching it and it was fine.  After booting the Apple //c, I started my program running.  After a little more than an hour it finished, with no noticeable difference in temperature.

I unwrapped the last power brick, went to plug it into the Apple //c and had some trouble with it.  The cord plugs into the back of the Apple //c and without turning it around I was kind of working blind.  The top of the cord is marked, strangely enough, TOP.

It didn’t seem to go in, so I looked at the cord and the outer covering was not quite straight.  Apparently it had been off at some point.  This cord came with an Apple //c that was crushed in shipping.  I twisted the covering to straighten it out a little.

It plugged in this time and I powered up the Apple //c.  This one I kept an eye on as I tested it.  I checked the brick and the cord several times while running the program.  This brick turned out to be noticeably warmer than the other two.  I broke out the trusty Dymo LetraTag, printed out a label that said WARM, and stuck it on the brick.  This one I could not sell.  I could use it as a backup, if necessary.

I came to a decision about the testing.   I would do it in steps.

I touched the power supply to get a feel for its temperature.  It felt a little warmer than body temperature, my guess would be 99 to 100 degrees F.

I planned to make the first run about ten minutes.  With my first test of ten loops it took roughly 2:17 to complete.  I multiplied this by five, ran it and got distracted and forgot to check on it for about an hour.  It should have taken a little less than 11 1/2 minutes.

I touched the brick again and didn’t notice a difference.

The next test would be longer, instead of doing the ten loops five times, I did them thirty times for an estimated 68 1/2 minutes.  This time I set an alarm and checked the temperature by touching the brick every twenty minutes or so.

When the run was done, I could not notice a temperature difference by touching the brick.  I also touched the diskette drive cases and the Apple //c case to see if there was any noticeable heat.  They were cooler than the brick.

It was not very scientific, but after this test I would be comfortable with buying or selling this brick power supply.  I suspect this is more action than most Apple //c’s get in general.  I know mine hasn’t had a workout like this in a while.

So now that I have a program to access the diskettes and draw a little power, what next?

How do I measure the results?  Do I run it for a period of time and if the power supply survives, it’s good?  If I do it that what way, what is a good amount of time?  An hour?  Two hours?  Eight hours?

Another option would be to check the temperature of the power supply.  Checking the Apple //c Technical Reference Manual, reveals only the input and output power of the power supply.  It doesn’t say anything about operating temperatures for the power supply.

The one I have connected to my Apple //c has been up and running for a couple of days now and is cool to the touch.  I ran the exerciser program twice in that time, once to see if it worked and once to time it.

I wrote a very short AppleSoft program, which just repeatedly does a catalog of each of the diskette drives.  The initial test I did was ten loops, cataloging each of my four diskette drives.  It took about two minutes seventeen seconds with the four diskettes I used.  I used The diskettes from Sneeze, ZLink, ADTPro and an 800K diskette with one file on it.

Over the years I have acquired two extra power supplies for my Apple //c, so I thought I would sell one on eBay.

The thing is, I wanted some way to test them first.  I can’t in good conscience sell one that isn’t going to hold up.  The problem for me is, on a technological level, I don’t know anything about electricity.  I expect there is some way to test them with a meter or something but, that is beyond me.

I figured the simplest way for me to test them was to use them on the Apple //c for a period of time.  Thinking about it though, just turning it on is not going to stress the power supply very much.  What would happen if I accessed the diskette drive or drives?  The Apple //c supplies the power for each of its diskette drives.

I thought it shouldn’t take much of a program to just keep periodically accessing the diskette drives.  I could whip up something in AppleSoft in no time.  Okay, so with my Apple //c I have 4 diskette drives; the internal 5 1/4″ and an external 5 1/4″, plus two external 3 1/2″ .  My first thought was I could ask the user to put ProDOS diskettes into each drive and then ask ProDOS what was online.  I could then cycle through each diskette drive and access it over and over for a given period of time.

I knew you could ask ProDOS what was online, but forgot you had to go though machine language calls to do it.  At this point it became simpler to just plan on there being a diskette in each drive and cycle through the four diskette drives using slot and drive designations.