>No, the max size of *central* storage is 2 GiB, but neither real storage nor auxillary storage is so limited.
>A little suprising for me.With 31-bit addressing,if you have 10G real storage,only 2G can be addressable as central storage.Then,how about the use of >other 8G real storage?Used as a substitiution for paging data sets? All sizes are limited by architectural or design considerations. Virtual storage is limited by register size (ie: 31-bit or 64-bit). Similarly real storage is limited in a similar fashion, as is auxiliary storage. However, real storage is limited by the same basic criteria as virtual storage ... Namely the size of the registers and the maximum address value they can hold. However, more real storage could be exploited indirectly by the fact that the operating system supported a way to move pages to and from this area (expanded storage) using special instructions (ie: MVPG), etc. This was not directly usable by the address space, but it could act as a high speed location for storing pages and I/O buffers for synchronous retrieval rather than using auxiliary storage. This form of support (expanded storage) was eliminated with z/architecture and the introduction of 64-bit registers and addresses. >Not quite. A 5MiB region is allocated, but that doesn't mean that there is 5 MiB allocated within that region. >Here I have another question.When saying 'a 5M region is allocated', does it include shared system area? No, the allocation is for user address space storage. Adam ---------------------------------------------------------------------- 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
