View source for Pentagon 1024 paging

{{Port
|Number=$EFF7
|NumberDec=61431
|PortMask=1110111111110111
|ShortDesc=Paging in Pentagon 1024K mode
|Readable=no
|Writable=yes
}}
bit 3 = 1 to overlay the bottom 16K with ram from 16k bank 0
bit 2 = 0 to enable Pentagon 1024 mapping and disable bit 5 port 0x7ffd locking, 1 to select standard zx128 mapping **
* ** Applies only when pentagon 1024 mapping mode is enabled via nextreg 0x8f.