Editing Addressing mode (section)

===Memory indirect and autoincrement===
The DEC [[PDP-8]] minicomputer had eight special locations (at addresses 8 through 15). When accessed via memory indirect addressing, these locations would automatically increment prior to use.<ref>{{
Citation
 | last1 = Jones | first1 = Douglas
 | title = Reference Instructions on the PDP-8
 | url  = http://homepage.cs.uiowa.edu/~jones/pdp8/man/mri.html#autoindex
 | access-date = 1 July 2013
}}</ref> This made it easy to step through memory in a loop without needing to use the accumulator to increment the address.

The [[Data General Nova]] minicomputer had 16 special memory locations at addresses 16 through 31.<ref>{{
Citation
 | last1 = Friend | first1 = Carl
 | title = Data General NOVA Instruction Set Summary
 | url  = http://users.rcn.com/crfriend/museum/doco/DG/Nova/
 | access-date = 1 July 2013
}}</ref> When accessed via memory indirect addressing, 16 through 23 would automatically increment before use, and 24 through 31 would automatically decrement before use.