From: joemonk64@gmail.com   
      
   > Memory models are something that mathematically arise from    
   > the concept of segmentation.    
   >    
   > The 8086 is segmented, ergo a full suite of memory models.    
   >    
      
   Nope.   
      
   The 8086 is a flat 1MB physical memory. Segmentation in the 8086/8088 arises   
   from the fact that the prior processor (8080A) was limited to 64K as it only   
   had 16 address pins. Segmentation is a VIRTUAL view of a PHYSICAL memory.   
      
   You can throw away segmentation, and still write an 8086/8088 program.   
      
   "The 8086 memory address space consists of a sequence of up to one million   
   individual bytes in which any two consecutive bytes can be accessed as a   
   16-bit data word. As shown in figure 4-17, the memory address space is   
   physically divided into two banks    
   of up to 512k bytes each.   
      
   "One bank is associated with the lower half of the CPU's 16-bit data bus (data   
   bits D7-DO), and the other bank is associated with the upper half of the data   
   bus (data bits DI5-D8). Address bits A19 through Al are used to simultaneously   
   address a specific    
   byte location in both the upper and lower banks, and the AO address bit is not   
   used in memory addressing. Instead, AO is used in memory bank selection. The   
   lower bank, which contains even-address bytes, is selected when AO=O. The   
   upper bank, containing    
   odd address bytes (AO=l), is selected by a separate signal, Bus High Enable   
   (BHE)."   
      
   Joe   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)