The HDR1 memory adapter is primarily designed to download the existing code from a stock Memcal.
It can be used for other things as well. For instance, if you want to use a UV eraser on your stock Memcal and then reprogram it without tearing stuff up, the HDR1 allows this to be done very easily.

Step 1: Take the stock Memcal (or whatever) and identify where the pins come out for the existing EPROM.

Step 2: Insert the HDR1 into the Memcal and note the orientation of the existing chip.

Step 3: Place the assembly into your favorite chip reader / programmer (AutoProm shown, chip notch facing ZIF handle, empty spaces nearest to handle).

Step 4: Go ahead and read or re-program the chip.

That’s it! No mess, no fuss. Pretty straightforward.