Here's a little treasure buried away in the vast archives of Shareware Plus. I uncovered it when I dug through the history of posts on the Shareware Plus blog. It caught my attention, but I really had no idea what it was.

It's listed as a "KERNAL ROM Adapter" in the latest pricing guide, and it's mentioned in the blog as a "Multi-KERNAL ROM Adapter". That certain sounds interesting. But, how do you use it and what exactly does it do?

I tried searching for this on the web, and came up with very little. picclick.com captured this description from when someone was selling it on Ebay. But, it's not available there anymore.

A simple switchable Kernal ROM adaptor which accepts programmed 2532 and 27xxx Eproms. The larger the Eprom the more Kernals you can have. Using the 10 position DIL switch you can select the Eprom type and which bank to use, allowing you to have a multitude of different Kernals all on the same ROM. For Example Standard Commodore Kernal, Jiffy DOS, Dolphin DOS, Quick DOS and many more. Instructions from Dela included (in German) freeweb — ebay.com, 2017

I sent Tim Harris at Shareware Plus an email asking if he had the documentation. He very kindly mailed me a copy, in exchange for my offer to make him a digital copy. But, I should have noticed from that Ebay listing above, the documentation is in German! Fortunately, it's only 2 pages, and Google Translate exists. So I typed it up, ran it through, cleaned up the inevitably crufty machine translation, and present it to you as a beautifully formatted PDF file, linked in the documentation section above.

If you happen to speak German, perhaps you'll get something out of the originals that I didn't get out of it. So, here's the original:

The documentation never actually refers to its use as a KERNAL (or Multi-KERNAL) ROM adapter. Rather, it is designed to be seated into an EPROM burner, and allows you to burn 27256 type EPROMs (32 kilobytes), in a programmer that only supports 27128 type EPROMs (16 kilobytes).

It does this by using a bank of DIP switches that can set the upper addressing lines allowing the burner (or the computer) to see a larger EPROM as multiple smaller banks. There is also a switch that can be used to vary the voltage supplied to the chip.

The instructions are centered on how to use the adapter with various types of EPROMs in the DELA Eprommer I, and how to use the software to divide a larger rom image into smaller chunks and burn them individually. As far as I can tell, this Eprommer itself is no longer commercially available.

If however, via a different EPROM programmer, you are able to write multiple 8K C64 ROM images into the four 8K banks of, say, a 32K EPROM, then this adapter can be plopped into the KERNAL ROM socket of your C64. By adjusting the DIP switches, the computer will have access to the different ROM images. Handy.