ZX Club - about the ill-fated #FF port.

         
                                
       
           
                                
  Owners various models
SPECTRUM'and will probably collide
dealt with the fact that on their computer
Some programs don't work,
working on other models.   
 There are many reasons for this:
 and incorrect hackers
 some "processing" and some
 installed correctly -
 signal duration
 nala INt, incorrect de-
 encryption of port addresses
tov, etc.                      
  Among the ports SPECtRUM'a su-
There is oneknown as
called "port #FF".  In various
In other sources, it is recognized that
existence, then is recognized with
with some reservations, then completely
is not recognized (with no less important -
with notes).               
  We are discussing this
like this: there actually is one
port (or its "imitation"), or
it shouldn't exist at all, for
the ordinary user bears this
significant.                      
 It is important for him (the user) that-
if his computer worked well,
and this is the main thing.                  
  Despite the fact that St. Petersburg
The Russian company "SCORPIO" has already
second time releases the model
"ZS 256 tURBO+", there are quite a few
owners of earlier models:
"ZS 256" and "ZS 256 tURBO". Para-
meters of bothearly boards are possible
improve by making it more rigid
decryption of port #FF. Rework
extremely simple and even accessible
for an inexperienced user (EU-
Are you still not sure of your
in their power, then ask them to do
someone more knowledgeable).      
  Participating in the alteration: m/s D57
(555LAZ), D58 (5SSЛН1), and also
processor Z80 (37th leg, or
bit A7 of the address bus, for those
who understands).               
 Designations are given according to
circuit diagram "ZS 256".
If you don’t have a diagram, but the names
chips are erased (in early
boards this took place), then, according to
Since Z80 everything is clear, two other
some m/s are located like this: look-
those on board in such a way that
two main connectors (one for
connecting the drive, the second -
for connecting power, TV and
etc.) were on the right.  Find a group
pc of color output transistors and
video (usually this should
be 4 orange transistors ti-
pa Kt315), standing in a row near
from the top edge of the board. A little bit
veethere should be 2 more of the same
transistor, immediately below them -
m/s D57. And even lower - D58.      
  Look at the conclusions D57 with ob-
rear side of the board.           
 Its pins 1...6 should not be
connected somewhere, i.e.  we
we have 2 free elements AND-NOT
of the 4 that are in 555LAZ.
We will use one of them
(legs 4...6).  For connections
take a suitable thin pro-
water in GOOD insulation.  Scheme
connections is as follows:              
                                
     
        
        
        
        
        
        
        
    
                                
  Check - 3rd and 4th legs
D58 also not connected anywhere. 
 If you have a board "ZS 256 tUR-
VO", then most likely the elements
the indicated microcircuits are occupied by
other goals. In this case, you can
but install the necessary m/s on
layout site.              
                                
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