2023-08-31 - Add "features to add" section (copied from apple notes)

2023-08-31--dev-notes.md

@@ -147,4 +147,17 @@ but mayber the second is easier to quickly read off of an LED display?
 “Typically, a microprocessor will, after a reset or power-on condition, perform a start-up process that usually takes the form of "begin execution of the code that is found starting at a specific address" or "look for a multibyte code at a specific address and jump to the indicated location to begin execution". A system built using that microprocessor will have the permanent ROM occupying these special locations so that the system always begins operating without operator assistance. For example, Intel x86 processors always start by running the instructions beginning at F000:FFF0,[46][47] while for the MOS 6502 processor, initialization begins by reading a two-byte vector address at $FFFD (MS byte) and $FFFC (LS byte) and jumping to that location to run the bootstrap code.[48]”
 
 → so i could just have a ROM
-→ or maybe two possible configurations? because sth more Cosmac-like or Big Iron-like would be fun too
+→ or maybe two possible configurations? because sth more Cosmac-like or Big Iron-like would be fun too
+
+## From apple notes -- "features to add / extended system"
+
+- convenience instructions
+  - mul
+  - div
+  - ? rol ror
+- ? return stack
+- interrupt
+- bank switching
+- peripherals
+  - keypad with DMA for entering programs
+  - ?? printer