ZX Pilot #35 27 ноября 1999

Железо

Hard & soft - bug-free music scheme of connection coprocessor AY-8910.

          H A R D A N D S O F T



(C) MISHEL



   As I'm tired of listening to the replica Friends
type: "Ha, hang!", and here's another: "M-Yeah!"
More or less: "Yes you sell your buggy
comp, we'll buy you normal! ". Nothing like this - if your 
computer hangs, it does not means that it is bad. He simply 
indigestible some programs and therefore have He indigestion 
memory. 

   Continue as more could not. All
These assaults have pushed (pushed) to ensure
to understand what was going on.

   Pozagruzhav visnuschie bend revealed
that if you turn off the music, then they work
normal. Conclusion: throw muzykalku and
work without glitches.

   Knowing that the truth is somewhere nearby, and making
PC hara-kiri, after pokapavshis in
fallen inwards, amounted to a scheme
podlyucheniya muzykalki along the paths, for lack thereof. So I 
connected: 


          DD1.4

        11
 A14 le1 13

                                DD1.1

                              2

        12 le1 a BC1
____ August 3
IORQ le1 10

         9 __
A1 WR 5

                                le1 BDIR

           DD1.3 6

          DD2.3 DD2.4 DD2.1 4

       9 12 1
A15 la3 8 la3 la3 DD1.2

      10 2 3
A13

              November 13



   To understand how the scheme
had poraskidyvat ports treatment for
bitikam:


    A15-A0
# FFFD = 1111111111111101
# BFFD = 1011111111111101

sistemnik for savneniya
# 7FFD = 0111111111111101


   15-th bit is only responsible for recording data in the 
selected case. 

   How does the scheme will not raspinovatsya - painful 
difficult but interesting draw plate as is reading and writing

AY:

  write read REC data transfer D0-D7

  REGISTER in Reg. y AY in the Z-comp.

BC1 1 1 0 0

BDIR 1 0 1 0

Dear coder, use in your program for the complete decoding port!


   Poraskinuv brains (scatter accounted for about three days) 
before I realized that program Weasley from the fact that when 
you access another port with incomplete dishifratsii some 
reason did not fire protection overlap with other ports on the 
element DD2.1 eventually scored music processor data bus for 
its data, there were (unwanted moments for digital technique, 
where two out together in one with it with different logical 
states) are small, but very scary shorts, because of which 
occurred almost hard reset the computer!


   Poizvraschavshis enough, I finally found the missing signal 
in this scheme. This M1, what kind of signal - I do not know, 
but finally get a little refinement, is to add signal M1 
decoder port. 

   For this we need (no, hammer
We do not need, but if the thought never leaves you, you can 
use it :-) two pieces of wire and payalo:


   1) break the track, which combines the inputs of the element 
DD2.4 so that the left connection of one input to output DD2.3 
(8). 

   2) inputs DD2.2 combine and serve on
an output of M1.

   3) sends a signal from the output DD2.2 (6)
free entry DD2.4.

   If you have a different scheme and there is no free item you 
will have to take mikroshemku li1, la3, LN1, 2, 3, in short, 
that you have is to collect and unpretentious shemki:



       1 instead of A15
A15 li1
M1 3

       2

       April 1
A15 la3 3 la3 six round-well

       2
M1

                 5


   Revised I finished watching the same demo
"CONDOMMED", which is terribly hung and honored nelko 
newspapers that Weasley, if their view on the lines.


   I would be glad if this revision to somebody
so help.

   Scattered brains Mishka, throw to friend Sashka.



   P.S. Many people probably noticed that the
board computer chip to the printer
available, and tests show that it is not
(Sometimes the same). Well, the fact that
developers of the scheme decided the case (will not be on the
They get angry): If you do not have the printer, then
Why do you need port. Port to work, we
need tinned porovolochka length
approximately 1 cm Seal it as shown in the diagram:


              connector on the motherboard


          ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■

         ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■

                D7 D0

__
WR 1 IR 23



A2

       1

               The whole thing in one resistance + FE lenii, 
which we closable, 

            thus setting at the entrance
            De chip logic "0" and

      1 allows a work port (as

            IR 23 is controlled to "0"). In this

            You can easily see if
__ Look slightly to the left on
IORQ decoding circuit port. TM 2

       1, this Triger from DOS, and the perk
            lyuchenie pages in ROM if the DOS

            the port is not working.



    TM2

       Q ■