HDS Gen 1 Map Chip Question

I have a Lowrance Lake Master Chip I’d like to use, but when looking at chart options it gives me Lowrance or Navionics. How do I choose the Lake Master Chip?

I’ll go out on a limb and take a guess. I suspect the unit is only programmed to give you two choices. Choice “A” or choice”B”, choice “A” being the internal maps built into the unit. Choice “B” being the external map inserted into the SD slot.

In this case instead of being labeled “A” (internal) or “B”(external) the labels are “Lowrance” or”Navionics”. I suspect if you want to read the external chip you should choose the “Navionics” menu option.

You choose Lowrance.

I tried the things that you have mentioned. It still won’t read the map chip. This chip works in my LCX 111 and my handheld GPS.