12. Hank Joins The Fan Club
Any full-size desktop PC without a fan feels like an anomaly in the modern day, and adding some airflow to your computer's case can reduce internal temperature and prolong the life of its internal components.
While some European variants of the Commodore 128 come with a fan pre-installed, the North American C128D-CR version I own did not include one. Luckily, it does include a pre-routed grille and mounting holes to accommodate an after-market fan.
The C128D supports a standard 60mm case fan with a maximum depth of about 35mm (1.5"). Both 5V and 12V fans are supported. Fans with a higher CFM (airflow) rating will move more air and provide better cooling, though this benefit will often come at the expense of increased fan noise and power consumption. I aimed for the midpoint of these extremes and selected a 20mm thick fan running on 12V and drawing 1.6W (~135mA), while delivering 26.2CFM worth of airflow at a 34.3 dB noise level. The fan I used can be found here.
The physical install is an easy 15-minute project that can be completed by an electronics novice with only a Phillips-head screwdriver (though a pair of needle-nose pliers and a wire stripper will likely come in handy). 2 case screws are removed from the computer's back, and the top chassis is slid back and lifted off to expose the motherboard and power supply.
The mounting holes on the computer's fan assembly aren't threaded and are obstructed from the back of the case, which means that the entire assembly (including the computer's power supply) will need to be lifted slightly to install the fan. This initially appears to be a daunting task but is also very simple to manage. Two screws are removed from the computer's back, and another two are removed from the computer's left side. Finally, one screw near the larger of the power supply's two transformers can be loosened but left intact, allowing the assembly to be tilted slightly.
The screws included with the fan were a little long for our purposes, but I was able to use an extra hex nut included with the fan as a stand-off, allowing a second nut to fit properly and secure the fan to the assembly. I was only able to mount two of the included four screws, but the fan was secured regardless, and it didn't seem necessary to use any additional adhesives or mounting.
There are two approaches to consider when orienting the fan. The most common approach (and the one for which the C128D was originally designed) sets the fan to suck air through the horizontal vents on the front of the computer's case and blows the heated air out of the back. However, some C128D owners discourage this configuration as it also pulls air (and dust) through the computer's floppy drive, resulting in dust buildup. Instead, a second approach pulls air into the back of the computer and blows it directly over the power supply. This results in less dust in the disk drive, but more over the power supply. I opted for the standard approach, as I feel it's more likely to encourage better overall airflow, with cooler component temperature as a result. I regret not taking case temperature before and after the fan install and feel that testing these approaches would make for a fun follow-up episode.
With physical mounting completed, the second half of installation involves finding a power source for the fan. An easy opportunity for tapping 12V lies in the large 5-pin motherboard power connector, which provides both 5V and 12V connections, as well as multiple ground connections. I didn't even need to remove the connector in this case - it was only necessary to twist the wires on each lead slightly (to ensure stability) and push them into the metal-and-plastic sleeve of the individual connector pins. For reference, the 12V connection on the C128DCR uses a yellow wire, while ground is indicated by the two black wires.
A quick power-up confirmed the fan was running properly, and the screws and case lid were replaced to finish the job. The fan noise is certainly audible, but is quite bearable (perhaps comparable to a quieter desktop PC of the early 2000s), and I feel a little more confident that longer coding or gaming sessions will be less detrimental to the computer's health. I'm very satisfied with this addition to my C128D and would recommend it as a simple and inexpensive project to prolong the lifespan of your own Commodore, with a suitable fan to be had for as low as $5-10.
This site is copyright 2023 Hank Wesley Chorkin. If you don't like it, you can get out!
Back