It looks inspiring! Does Bla have any kind of indexing or aggregate data structures? IIRC Tiny Basic had one array that was the leftover part of memory, which is enough to do a lot.
You have to manually carve up the heap into arrays if you want to have more than one. If variable F points to the start of an array then F,I@ will read F[I] while 42!(F,I) is an assignment F[I] := 42. The comma operator is just to convert a word index to a byte index, so F+(2*I)@ and 42!(F+(2*I)) also work but are uglier.
