drop of solder - On completion computer Scorpion ZS256 (Revised Scheme AY).

<b>drop of solder</b> - On completion computer Scorpion ZS256 (Revised Scheme AY).

(C) 1997 DANIIL
 On completion the computer Scorpion ZS 256.
__________________________________________


                  *

 In this article I will tell you about
small improvements computer "Scorpion
ZS 256 ".
 Everyone has long known that the firm "Scorpion"
released a new fee turbo +, N / O even so,
There are many people who have "old" board on this machine.
 Discussed in this article will be discussed is the "old" 
Scorpio (because the owner of those is me!).  The newspaper 
"ON-LINE" # 11, as well as the "ZX-REVIEW" number 04/05 for 
1996 was published wiring diagram AY. After this revision 
should play Digitization Mouzon, and also work correctly editors

"DIGITAL STUDIO" and "INSTRUMENT". All as
say, OK, here is interpretation of the above
publications at the end of the following is written (quote 
verbatim):  "In" buggy "computer work with our

scheme (which has a very small percentage of probability) 
should change the signal IORQGE on IORQ. "unquote.

 Now I will openly declare
that this scheme will fail with 100% probability, in 
particular, will not work F.I.R.E., ALICE demo, etc.

 The thing is that this scheme is flawed because it does not 
take into account the cycle interrupt confirmation Z80. During

this cycle processor nimenuemo will "contaminate" the data bus 
(ie, at the time of interruption on it will not # FF!).  And I 
would like to mention the fact that This bug will only occur

If the interrupt vector I will be in the range # C0-# FF.
 And now, not to be unfounded, I
give an outline of refinement, in which this
bug does not exist:

(C) 1996 DANIIL / PLAYGEAR.
 Revised scheme for AY Scorpion ZS 256:
 Unused item D3.1 chips
LL1 can be used in refining "disconnector port # 1FFD" 
published in ZX-Format # 1 (legs 1,2,3).

 This revision is installed on my
Scorpio, no glitches not identified! Chips are mounted on the 
free space on the board (if you still have ...), all 
connections are wire. Probably not worth mentioning that the 
shorter wire is better!  Owners pay Turbo + worries do not have 
such a scheme implemented by the company. 

 Now a few words about the disconnector # 1FFD. Like I said, 
the scheme of his published in the ZX-Format # 1, again all

OK, only the marking circuits shown
for older motherboards. I would like to give the corresponding 
notation for the new cards turbo +:



             turbo-turbo +


              D49 D47

              D53 D52

              D52 D45


 Finally, another useful information
concerning the old boards. If you have erased
the marking of chips on the motherboard, then I'll show you how 
to find them: 



             D52



              AY-8910 D53



                           D49



          about


  It's all about what I wanted to tell in this section of the 
first issue DEJA VU, naturally in subsequent issues, we will 
continue the theme of hardware and try to give attention not 
only Scorpion'am.  In addition, we would be happy to receive 
information from you, uzhazhaemye readers. Send us your stuff 
and we will gladly publish them. 

END ...