Hang in there - it's not that bad. It's just that the ISD1700 has a TON of features and options so it's overwhelming to sort out the datasheets and find what you need.

As soon as I am able, I will post some more code examples (PicBasic Pro and Liberty BASIC). I have all the record and playback functions working fine using SetPlay and SetRecord. The PIC firmware (PBPro) translates serial commands from the PC (Liberty BASIC Windows app) and controls the ISD1700 for record, play, erase, etc.

Note: I use DEBUGIN so no UART or level shifter is required for the PC to PIC serial connection.

As far as addressing, for SetRecord and SetPlay you must know the Start and End address of each sound. To make addressing easier, I just divided the ISD memory into predefined "blocks" of 1,2 or 4 seconds. This way I always know the Start address of each sound, and I use the EOM function so I don't need to know the exact length of the sound during playback (it stops automatically when it hits the EOM marker even in SetPlay). So I can replace (re-record) any sound as long as the new sound fits within the block.

Tip: When you are using SetRecord, you must specify the Start and End address. But you can send a STOP command before the End address is reached and the ISD will place an EOM marker at that spot. If you enable the EOM function, playback will stop at the EOM regardless of the End address - even when you use SetPlay!! This is very cool, and it's what allowed me to use the pre-defined memory map without knowing the exact length of the sounds.

It's not the most efficient use of available memory, but it's simple and the software/firmware does not have to calculate length of each wav file and write locations to a table. The table is pre-defined. It works well for my application (Laser Tag) as I just need to trigger a few short sound effects, and my customers want to be able to replace the stock sound effects with their own custom sounds.

Jim