bkahn@archive.rtp.dg.com (Bruce Kahn) (07/31/90)
I am new to programming the 68K and have a quick question for you Mac C gurus out there. What is the byte ordering of the values generated by both Think C 4.x and MPW C 3.x? I own both but cant seem to find the information in any of the manuals. Also, can someone pls tell me the sizes and values for variables declared as Ctype * under Think C? Under MPW its 4 bytes, 0 to 4294967295. Thanks. Bruce (bkahn@archive.rtp.dg.com)
minow@mountn.dec.com (Martin Minow) (07/31/90)
In article <684@dg.dg.com> bkahn@archive.rtp.dg.com (Bruce Kahn) writes: > > I am new to programming the 68K and have a quick question for you Mac C >gurus out there. What is the byte ordering of the values generated by >both Think C 4.x and MPW C 3.x? I own both but cant seem to find the >information in any of the manuals. They probably wanted you to ignore the byte ordering (doing so makes your code portable to a "real" computer, such as a Vax). If you must know, try writing a program like union { short foo; char bar[sizeof (short)]; } stuff; int i; for (i = 0; i < sizeof (short); i++) stuff.bar[i] = i; printf("%x\n", stuff.foo); to see what the order is. > Also, can someone pls tell me the sizes and values for variables >declared as Ctype * under Think C? Under MPW its 4 bytes, 0 to >4294967295. Thanks. Pointer types are 4 bytes in both implementations. MPW int's are 4 bytes, I am told, while int's in Think C are 2 bytes. Either is "correct" given the Motorola 68000 architecture. Here, too, printf("%d\n", sizeof (Ctype *)) would give you the answer. Martin Minow minow@bolt.enet.dec.com