On Fri, 9 Apr 2010 17:57:04 -0400 (EDT), John Hasler wrote: > Stephen Powell writes: >> Yes, Hercules is an IBM mainframe emulator. But the problem is >> licensing. There are some *very old* releases of IBM operating >> systems that have passed into the public domain that you can run on >> the Hercules emulator. >> These are circa 1975 or so, which is about 35 years ago. An example >> is VM/SP Release 6.
Oops! I meant to say VM/370 Release 6, not VM/SP Release 6. VM/SP Release 6 is still proprietary. ----- These are some of the issues that someone writing portable code for ASCII vs. EBCDIC implementations needs to worry about. (1) Collating sequence. In ASCII, the collating sequence is numbers (0-9), followed by uppercase letters (A-Z), followed by lowercase letters (a-z). Special characters are mixed throughout. In EBCDIC, the collating sequence is lowercase letters (a-z), followed by uppercase letters (A-Z), followed by numbers (0-9). So records sorted alphabetically sort in a different order. (2) Assumptions of continuity. In ASCII, the codes a-z and A-Z are contiguous, with no codes in between. In EBCDIC, there are six non-contiguous ranges, a-i, j-r, s-z, A-I, J-R, S-Z. Most of the codes in between are non-printable characters, but not all. For example, ~ sorts above r and below s, } sorts above I and below J, and \ sorts above R and below S. (3) Hidden assumptions about control codes. A program may, for example, assume that X'0A' is a line feed and hard code it somewhere. In ASCII, that is true. But in EBCDIC, a line feed is X'25'. (4) 7-bit assumptions. In U.S. standard ASCII, all the printable characters are between the hex values of X'00'-X'7F'. Codes above X'7F' are not standard codes. Historically, these indicate the combination of the "Meta" key with a regular code. In EBCDIC, the codes are sprinkled throughout the entire range of X'00' through X'FF', with the numeric symbol 9 having the highest code of any normal printable character (X'F9'). This is not an exhaustive list, but it gives you an idea of what to watch for. Although the following table has a few mistakes, this link will give you an idea of ASCII vs. EBCDIC codes. http://www.natural-innovations.com/computing/asciiebcdic.html -- .''`. Stephen Powell <zlinux...@wowway.com> : :' : `. `'` `- -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/8691664.2246941270858506206.javamail.r...@md01.wow.synacor.com
