Re: Why I've Dropped In

On Fri, 13 Jun 2025 6:03:02 +0000, Thomas Koenig wrote:

Also, just discussed: Throw out the base registers and put in
memory operations with 16-bit offset.

Upon further reflection, base registers did not simply exist in the
System/360 architecture in order to allow programs to be placed in
memory in different places, which meant they were obsolete when virtual
memory came along.
They also existed simply in order to allow a program to use a larger
amount of memory than would be economical to specify fully in every
instruction. So if they threw out the base registers, the memory
operations would have had to have a 24-bit offset, not a 16-bit one.
And that would grow to 32 bits and 64 bits in time.
John Savard