From: nowhere@nevernet.at   
      
   On 10/10/2022 11:17, muta...@gmail.com wrote:   
   ...   
   > This is a once-off instruction to be executed.   
   >   
   > There is nothing magical about 4 bit   
   > shifts that are totally memory efficient, zero   
   > fragmentation, but 5 bits would be   
   > totally horrendous, unacceptable to the   
   > whole world without exception.   
   >   
   > Personally I want 2 mb of memory   
   > rather than 1 MB, and I'll wear the   
   > slightly inferior fragmentation.   
      
   I once upgraded my Z80 based mini-PC boards   
   with a memory add-on to have 1MB static RAM   
   in mapped into the Z80's 64KB address range.   
   it needed one 8 bit I/O to add +4 address-lines   
   and 4 bits for variable gating 16 memory banks.   
      
   it turned out that one 64 KB block from the 1MB   
   wasn't accessible, but WTF: 1MB on Z80 worked.   
   __   
   wolfgang   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)