Retro computing with a touch of modern and the home for all things, retroCombs (aka Steven Combs).

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28 June 2021

Replacing my Original Commodore 128 and using a Keelog Power Supply

by Steven B. Combs, Ph.D.

As readers and watchers know, I’m slowly adding to my collection of retro and modern retro-inspired collection of computers. With a focus on Commodore, my collection now has one working and three “for parts” VIC-20s, a Commodore Plus/4, The VIC20, The C64 mini, and a MEGA65 DevKit. In this blog post, and companion video, I share my recent eBay purchase addition; a Commodore 128.

Table of Contents

Before you read the rest of this post, view the companion video below.

YouTube Video: FAST LOAD: Commodore 128 and Keelog Power Supply | New additions to my retro-computing collection

In the Fast Load video below, I share my Commodore 128 eBay purchase.

Video Errata

2021-06-28: I inadvertently call the Datasette connector, the user port when describing the connectors.

Below are the links I mention in the video. All Amazon links are affiliate links. My thanks to everyone who supports the blog and the YouTube channel!

  1. Keelog Power Supply
  2. Hyperkin Ranger Controller
  3. Kung Fu Flash
  4. Crazy Blaster
  5. Video Cable
  6. Portable HD Monitor

My Commodore 128 history

The Commodore 128 was my second computer and was my daily driver during most of my college career. Combined with GEOS, a 1351 mouse, and a Star Micronics NX-1000 Printer, I created lab reports and papers that rivaled, and I would say exceeded, the quality of many of my Mac loving friends.

Star Micronics NX-10 Printer Source: eBay

One of my favorite courses in college was Technical Writing and not just because of the content, but because the instructor was an early adopter of the use of computers and encouraged students to step beyond the typewriter to learn more about the possible with newer affordable computers. His daily driver was a college purchased Mac. I’m unsure of the model; however, I know it a premium model with many upgrades.

I vividly remember turning in an early written instructions assignment assignment. While most students turned in typed copy with pasted (I mean actual pasted, with glue) images, I painstakingly drew every image with geoDraw and inserted them in line with the copy. When I turned in the printed copy of the assignment to my instructor, he said, “You must have a Mac.” When I explained to him, I couldn’t afford a Mac and was using a Commodore 128 and GEOS. He said, “Well, it’s all about the final product!” This statement made a lasting impact. A+ and that was a course that still informs me in the 2020s as I continue my journey to write in active voice and create educational content that integrates multiple types of media.

In the late 1980s, I sold my beloved Commodore 128 so I could purchase an Amiga 500, which would be my daily driver throughout my later college years and during my time at the United States Army Armor School. Looking back, as we all do, I wish I’d kept my original. When I sold it, it was in excellent shape and included a Commodore 1902 monitor so I could use both 40 and 80 column modes. When I sold both the computer and monitor, it was just enough to purchase the Amiga 500 alone. More on this story, if I ever decide to add an Amiga 500 to my collection.

The Commodore 128 eBay Purchase

While working my way through my Commodore Plus/4 User’s Manual and trying out BASIC 3.5, I became nostalgic about my old Commodore 128. I’ve conducted searches on eBay for a replacement since January 2021 and had lost bids, or been leery about the operational integrity of the systems available.

In June of 2021, I thought I would win a bid on a C128D. While not the model I owned previously, it was a C128 with a cool form factor. I lost that bid; however, I was following another C128.

Commodore 128D Source: Rama, CC BY-SA 2.0 fr

The price was just over my threshold for the Buy It Now asking price and the seller did not offer the Make and Offer option. This was a beautiful C128. The listing included excellent images, information about the seller’s restoration process, and a 30-day money-back guarantee. The computer looked brand new!

About twenty-four hours later I, and every other person watching this item, received a 15% decrease in price offer. I quickly engaged the seller and began some negotiations. Turns out, he was one of my YouTube channel watchers! We settled on a price, he resent me the offer, I made sent PayPal funds immediately, and four days later, a box arrived on my doorstep. Even when a seller has excellent ratings on eBay, you always wonder, “Is what arrived, what they promised, and did it arrive safely?” Let’s find out later in this post.

Purchasing a Commodore 128 Power Supply

The C128 did not include a power supply. The seller offered to sell me an original power supply for $50. I politely declined and let the seller know that I’m a fan of mixing modern with retro, my theme as readers and watchers know, and old power supplies have a history of “borking” their original computer counterparts. Instead, I turned to the Keelog C128 Power Supply with OLED Screen. That’s Keelog and not the cereal maker, Kellogg!

Keelog C128 Powers Supply with OLED Screen Source: Keelog

With decent reviews and the specifications below, I am confident this power supply will provide more protection and add years of life to this 1980s computer.

Keelog C128 Power Supply Features

*  Stabilized 5V/3.0A DC output with anti-ripple filter
*  OLED display with digital voltage and time readout
*  Touch sensor for toggling OLED display screens
*  Transformer-generated 9V/1.1A AC output
*  Over-voltage and over-current protection
*  Fused on AC and DC side and fully isolated
*  High quality chassis with digital OLED display
*  Durable and thick cables on both sides
*  Runs cold
*  Weight only 0.6 kg (1.3 lb)
*  Compact enclosure with modern shape 125 mm x 59 mm x 42 mm (5.0" x 2.3" x 1.6")
*  Square DIN5 plug with 5V DC and 9V AC
*  US-standard 120V AC power plug (U.S., Canada, Mexico, Japan, and others)

The power supply arrived a few days prior to the Commodore 128, adding to my anticipation. I left the power supply in the box knowing that I would open both item’s box at the same time and document this in the companion video.

Unboxing the Commodore 128

With both the C128 and power supply in hand, it was time to see if what I purchased was what I received. I set up my table, turned on the lights, grabbed my dull Swiss Army Knife, cut into the outer packaging with excitement. While the seller did not include the original box, this did not diminish my excitement. In a few minutes, I would once again hold in my hands a computer I had not touched since the late 1980s. I was giddy with excitement as I made my first cut into the area the seller had conveniently marked, “Open Here.”

With the box open, I noticed the seller had done an excellent job packing the computer. Inside was bubble wrap, air pillows, and a computer surrounded by foam padding. The C128 safely made the trip over three states to get to my location thanks to the care the seller took to package the computer correctly.

After removing the packaging, I could immediately tell the seller delivered what he promised. The C128 was immaculate. It was clean with nary a scratch. I felt as though I held in my hands a mint condition, C128. I placed the C128 on my desk and tapped a few keys. When I hit the space bar, it “jiggled” loosely. “Oh, no,” I thought to myself. “They damaged the keyboard during shipment.” I then remembered my experience with a past Commodore spacebar. I placed the spacebar directly over the connectors, pressed down until I heard a faint click. All was right with the world. It was now time to hook up that fancy new power supply and turn on a C128 for the first time since the 1980s.

Powering Up the Commodore C128

I connected the Keelog power supply to the C128 and then into the wall, hoping smoke would not follow; and it did not. I connected the video to my Cloner Alliance Box Pro’s composite video port using a 5 pin DIN to four RCA port adapter. The cable sends the output to a LePow portable HDMI display. I use a Vassink HDMI switcher to plug in several HDMI sources to the monitor at one time such as my MEGA65 and TheVIC20.

I turned on the computer and low and behold, the familiar C128 green and gray screen complete with … NOTHING! “Oh, no!” Again, my mind assumed something was wrong. And wrong it was. While tapping the keyboard earlier, I hit the 40/80 column button on the keyboard. The computer was in 80 column mode. I turned the computer off, tapped the 40/80 column key, turned the computer back on, and TADA!; on the display was the familiar screen announcing:

         (C)1977 MICROSOFT CORP.


With everything functional, I ran some quick and rudimentary tests.

Testing the Commodore C128

The first thing to do was run the all important retroCombs version of the “Hello World” program as shown below.

20 GOTO 10

RETROCOMBS scrolled continuously across the screen. First test complete. Next it was time to test Commodore 64 mode using the same program. At the C128 prompt, I entered GO64. The display presented the familiar C64 blue colors. I typed in the code and entered RUN. Yep! C64 mode works. With both modes verified and no CP/M disk in sight, I moved on to other non operating system tests.

I pulled out TFW8B’s Crazy Blaster C64 game cartridge and a Hyperkin Ranger controller. With the C128 power off, I plugged both devices into the computer and turned it on. The screen displayed the Crazy Blaster title screen; however, the sound was indistinct. I couldn’t change the volume on either the capture device or the LCD monitor. I don’t fault the C128. This is probably something I need to research. Everything else worked. I moved on to my next test.

Along with my purchase of Crazy Blaster, I added a Kung Fu Flash cartridge to my cart. My original intent was to use this cartridge with my MEGA65 DevKit; however, cartridge support on that computer is still hit or miss. I was eager to see how it would work on the C128 in C64 mode. I believe it will work in C128 mode, but I have some reading to do.

I plugged the Kung Fu Flash cartridge into the powered off C128, flipped the power switch, and the Kung Fu Flash menu was on the display. The computer booted directly into C64 mode. This is no review of the Kung Fu Flash; however, this thing seems amazing! I can’t wait to spend more time with it.

There was only one odd thing I noticed about the C128. Sometimes a joystick installed in port 1 will make the keyboard inoperable. Again, I’m not sure I fault the C128 until I perform some tests and read some troubleshooting documentation. Despite the volume and joystick issue, everything works as expected.

I have many other tests to run including a Wi-Fi modem, Pi1541, and several additional software titles. Those will occur as I familiarize myself again with the Commodore 128. I look forward to every session.

The Only Remnants of my Original C128 Collection

When I made this purchase on eBay, I remembered I had one item leftover from my original C128 days; a book entitled Commodore 128 Troubleshooting and Repair by John Heilborn. Grabbing the book from my bookshelf, I thumbed through the pages. I purchased this book in 1989 at the Readmore bookstore in my college town and it sat on my shelves in case I needed to make repairs to the C128. I never did, and the book remains in excellent condition, save for a corner on the back cover. These many years later, I now plan to read through this book, “for fun.” I will learn much about the newest addition to my retro-computing collection and now feel more comfortable performing repairs than I did 30+ years ago.

Commodore 128 Troubleshooting and Repair Source: Lemon 64

While flipping through the book’s pages, I found a wonderful surprise; a geoDraw computer drawing I made that compares the size of the original 1701 starship Enterprise with the newer Next Generation variant, the 1701-D. While I don’t have the original electronic file, and I wish I did, it was wonderful to find this printed version. It brought back all those splendid memories of other documents I created with GEOS on my Commodore 128.

Final Thoughts

I am thoroughly satisfied with my Commodore 128 purchase and look forward to using it and documenting my experiences. This device will pop up in future blog posts and videos as I reacquaint myself once again with the computer I always considered, the king of the Commodore 8-Bits!

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🕹️ retroCombs, OUT!