[plug] Free CD linux - any good ?

[Kevin Shackleton]

David Griffiths wrote:
> 
> Well spotted! silly me - the size of the data bus has nothing to do with
> the size of the address bus which is 24 bits in the SX and 32 bits in the
> DX.
> 
> >       How does that work then?
> >
> >       16 bits is 64k addressable in my book....  or was there an 8 bit
> >extention of some sort, which would give you your 24 bit addressable
> >(16M)???
> >
You were right the first time (more or less) - you get 20 bits of
address space in a 16 bit 8088/8086/V20 (note - no difference between
the 16-bit 8086 and the 8-bit 8088) because you actually address 4-bit
space (16 byte) paragraphs.  A very silly idea when it comes to
assembler.  I think the 386SX has the same 32 bit address space as the
DX, only it has to pump out the address in two clock cycles having a
very limited number of pins, half of which are multiplexed to different
uses.  The fact that 386SX mobos were usually issued with 4 * 30-pin
DRAM slots does tend to restrict you to 16 MB though.

While I'm dribbling on, has anyone seen the AMD chip used in the
wireless LAN access points that Microgram are selling.  They're AMD 333
(?) chips but not even 1 cm square.

K