During the process of searching for interesting type-in games and programs from a few select volumes of old Commodore magazines (in PDF), I happened across a very interesting 1541 fast loader, called TurboDisk, by Don Lewis. It was originally published in issue #59 of Compute! Magazine, back in 1985. However, I first discovered it in the special compilation book Compute!'s Commodore Sixty Four & 128 Collection, published that same year.

According to the article, TurboDisk increased the 1541's LOAD speed by a factor of three times or more. What makes this fast loader stand out (at least for me) is that it's the only one I've seen that loads part of itself into the 1541's CPU, which works in tandem with the other portion running on the C64. I thought that was pretty cool! So, I just had to give it a try.

I spent the next couple of hours typing in the BASIC code, printed in the magazine, into VICE. Later I discovered that there was a copy of the magazine article, over on AtariMagazine.com, here, which I could have used to save me some typing. But, overall, I enjoyed reliving the experience of having to take the time and do my own work.

The program that you type in isn't the fast loader, itself. It's actually “preparation” program which creates a machine language program on your floppy disk, which is the fast loader that gets saved to disk. Then, when you want to use it, you LOAD the program and run it by issuing a SYS49152 command. The TurboDisk then loads a portion of itself to the 1541 and is then ready for use.

All of the details about how the program works can be found on the AtrariMagazine's page. But, the big question is, does it work? You bet it does, and it works pretty darn good, too! From what I can tell, the larger the program, the faster it seems to go.

Here is a video I've recorded of a side-by-side comparison of loading a game with and without TurboDisk. The game I'm loading is LazerTech and is 108 blocks in size. On the left is VICE running normally, with no TurboDisk and no “warp mode”. On the right is VICE with TurboDisk loaded and ready to go. You'll see there's quite a variation in LOAD times. I was quite impressed.

If you want to give TurboDisk a try for yourself, I've also provided a link to a disk image containing the programs I typed in from the magazine article (if you don't want to type it in for yourself).

Composed using ArcheType on my C128.

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