Couple of days ago I've started looking for some infos about official PCE SDK. I haven't found too much but meanwhile I read on Dave Shadoff's page about Develo books. Most interesting part was related to "patch files". So... a few downloads and hex views later I crafted tiny script for QuickBMS. It extracts mentioned files from data track of Develo Starter Kit , both Assembler and Basic. There's couple of interesting files here and if you start digging more you'll find some extra files hidden in DUMMY.$$$ from Basic disc. Just to make it clear, data track needs to be extracted from CD image using TurboRip or anything that will save 2048 sectors ISO file. Edit: just for the sake of completeness, added another one for Develo Magazine Volume I.