(IBM Mainframe Discussion List) wrote:
Back in the days before paging systems, back when there was no virtual or real storage, back when storage was just called "storage", EXCP would execute
You had storage? All of our programmers had "core", and persisted in that usage even into the late seventies.
remember for sure, but it was probably possible for a caller to have a read command executed with a storage address that would cause data being read to overlay storage that was outside his region, partition, or whatever the big chunk of
Potential storage overlays were controlled by protect keys, providing the hardware supported them and the operating system set them correctly. In PCP all of storage was fair game, in MFT and MVT it was harder (there were a couple of loopholes in SVC parameter validity checking that IBM fixed eventually). I do remember clobbering storage in MVT reading a 2314 sized track buffer from a 3330, and lucking out with an add-on memory whose protection capability had not been configured correctly.
Gerhard Postpischil Bradford, VT ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
