Some time ago I finally got my hands on a vintage Commodore SX64. This is one of the first ‘portable’ computers ever made and weighted a whopping 10.5Kg!! I had fond memories of this machine and always wanted one since I was a kid. The SX64 is basicly of a regular Commodore 64, VIC 1541 diskdrive and a 5.5″ colour CRT monitor. It was passed to me when the dad of a good friend passed away.
The unit I got was in reasonable shape and it only needed a good cleaning and some TLC to shine again. The unit seems to be touched in the past as the kernel was replaced by a regular C64 one. Also the serial number on the motherboard didn’t match the one on the back (however by studying pictures on the interwebs this seems to be common?) . I tried to order an original kernal second hand on ebay or marktplaats (our national eBay), but didn’t found one. Not a big deal as I planning to replace the kernal with JiffyDos. I used my 27C512 to 23C64 adapter for this and store the original chip somewhere safe. Opening the beast revealed that it was not easy to service as any parts were obscured by other parts, had not easy to remove parts, different screwheads, weird board interconnects. Nowadays more detail is put into that, but for the 80s this is a feature!
To test the machine I asked an old friend of me to come over and we played megademo’s. He brought an old box of floppies with him for the feel of the old days. I did replace the C64 kernal and diskdrive kernal with the JiffyDos variant so loading times weren’t that long. However it still takes ages compares to our modern-day computers. My original plan was to first use a diagnostics card to check the machine working, but it passed the megademo’s test with flying colours, so I skipped that part. Even the diskdrive read the ancient floppies without a problem. Not bad for 40 year technology.
I also redesigned the cartridge slot to accommodate an ‘internal’ cartridge. It has additional circuitry to shut off when a regular cart is detected. It fits perfectly into the machine almost unnoticed (besides the extra functionalities). There will be another post covering that.
One of the other things I did was to clean the keyboard. This one scared me the most as this one is custom made for the SX64, and its construction is very delicate. Spare parts are very rare and costly on Ebay. As a backup plan I did find someone who makes replacement membrane keyboards. Luckily with some help from internet and some patience it went well to just clean the old one. The replacement wasn’t necessary, but handy to have one spare.
Since I like to keep thing as original as possible I didn’t throw the old original parts but kept them in case I or someone else wanted it restore in original condition. However I like to obtain an original kernal for this so if anyone has one..
In memoriam of Huub Kelly,