Oberon #03: Hardware: Connecting AY-3-8910

-----------------------------------------         (C) DR.DEATH/SPEED Co.'97        
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About connecting AY-3-8910(8912).     
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Recently, there has been a large number of SPECTRUM compatible machines, which either do not have a music coprocessor, like PENTAGON 128K, or have such a defective connection that a large part of Russian SOFTA is simply silent, for example SCORPION ZS 256, on which it is impossible to listen to or write DIGITAL SOUND. On most machines, it is impossible to listen to digitized music written in brotherly Poland, as the 'smart' Poles do something like this before "throwing" data to the port:                         
                                          
OR   #80                       
OUT  (#FD),A ,                 
                                          
while most of our machines require doing:                                   
OR   #A0                       
OUT  (#FD),A                   
                                          
These glitches made me reconsider the connection scheme of AY-3-8910(8912).   
                                          
In the scheme I present, all known shortcomings have been eliminated. The coprocessor does not "pollute" the bus during the command fetching by the processor, as the M1 signal is introduced: the sampling of the music coprocessor is now independent of the state of A13, and thanks to this, there is DIGITAL SOUND in all Polish demos...                
Now, let's go directly to the scheme:

If you understand the principle of operation of this scheme and understand where all the signals for the functioning of the scheme come from, then go ahead for the soldering iron, and for those who are new to our ranks, I will explain how to launch this very scheme.                                     
All signals like M1, not WR, A14, A15, A1, not IORQ, RESET can be taken from the system connector of your computer, if available. But if you still do not have a system connector, then take these signals from the corresponding pins of the Z80.               
Signals D0-D7 go to the corresponding pins of the Z80 processor.                          
The signal with a frequency of 1.75 MHz can be taken from:
                                          
Moscow 48k    2D3                  
Leningrad 1   2D35                 
Leningrad 2   2D3                  
Pentagon 48k  2D10                 
Pentagon 128k 2D3                  
Moscow 128k   2D3                  
If your machine is not on this list and you do not know where to get its (frequency), then look for 1.75 MHz in the area of the clock generator on the scheme. A signal with such a frequency may exist either on the chip 5SSUES or 5SSUE7, there are options. If you are too lazy to search for anything on some scheme, just repeat what I drew in the lower left corner.            
                      
╔════════════════════╗
║     WARNING!!!     ║
║                    ║
║ Power to the micro-  ║
║ scheme 5SSUES is supplied ║
║ to pins 5 and 10     ║
║ legs: +5V and ground  ║
║   respectively   ║
║                    ║
╚════════════════════╝
                                          
                                          
Signals from the outputs
of the coprocessor can
be combined, as
you please.        
 For example, connect
all outputs into one,
as was done on the branded 128k
SPECTRUM.         
 And if you have a poor imagination, then
I suggest my option (see the drawing).   
                    
 I indicated on the scheme
the main option
ABC  STEREO, like
mine, although now
more and more people
write under ACB STEREO.                     
Well, at the end of the article, I will give a couple of small tips:                                  
1. If your machine does not play digitized sound in Polish demos, just disconnect the A13 signal from the coprocessor sampling scheme and instead apply the A15 signal.                                      
2. If the M1 signal is not fed to your coprocessor sampling scheme, then for reliability, it is better to introduce instead of the A14 signal simply a mixture of signals A14 and M1 through any 'AND' element, for example 5SSЛИ1.
                                          
Now, if there are no questions, let's get to work!
                                          
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Contents of the publication: Oberon #03

• From the Authors
  The editorial of the third issue of Oberon reflects on its wide distribution across Russia and nearby countries, overcoming production challenges, and its aim to cater to various readers, including gamers, programmers, and hackers.
• How to Write in Oberon - M.M.A
  Guide on submitting articles to Oberon using ZX-WINWORD. Detailed format and process explanations for text, graphics, and music. Insight into editorial practices and preferences.
• Scroll - M.M.A
  A historical overview of the game THE EIDOLON on ZX Spectrum, covering its restoration process and gameplay mechanics, including level challenges and story background.
• Scroll
  Dark Star is a space shooter game where players pilot a ship against a tyrannical alien race. Players customize settings, navigate space, and combat enemy forces on various difficulty levels. Strategic planning and skill are vital for successful gameplay.
• Scroll - M.M.A
  Detailed gameplay mechanics for the game with Mechnotech klp2. Strategy involves disarming reactors and managing droid transformations. Insight into different droid types and weapons available.
• About Everything - M.M.A
  Discussion of reader interactions with the 'Oberon' editorial team, including feedback on previous issues and commentary on game compatibility and magazine content improvements.
• About Everything - M.M.A
  The autobiographical article explores the author's role in Samara's ZX Spectrum scene, detailing his contributions and aspirations. M.M.A positions himself as a leader and innovator in the community. It highlights the importance of local distribution and cultural impact.
• Amiga rulez? - M.M.A
  Critical essay on contemporary computer culture, contrasting IBM and Amiga platforms. Discusses societal impact of IBM standardization and advocates Amiga as a symbol of creativity and individuality. Reflects on the evolution of computer usage and preferences since the ZX Spectrum era.
• What Should 'Boot' Be - Unbeliever
  The article explores the evolution of boot programs for ZX Spectrum, discussing early developments and key innovations over time. It highlights significant breakthroughs in automation and design, including fully assembler-written boots and the introduction of modern features. The text concludes with reflections on ideal boot characteristics from a contemporary user's perspective.
• Letter from Queen Software
  An open letter from Queen Software criticizes ZX-WINWORD's design and Russian keyboard layout, denounces 'Mortal Compot' and the degradation of games, and shares views on demoscene events and computer emulation.
• Review - Unbeliever
  The review provides insights into various 128K exclusive games for the ZX Spectrum, highlighting titles like 'Space Gun', 'World Championship Soccer', and 'Night Breed'. Special attention is given to their graphical prowess and gameplay mechanics. Furthermore, the article addresses the acquisition of Spectrum software via the Internet.
• Review of Assemblers - Maxsoft
  Review of various assemblers for ZX Spectrum, highlighting their strengths and weaknesses. Focus on EDAS 3.3, AFS, XAS, ZX-ASM, ALASM, MASM, and TASM 4.1. Each assembler is evaluated on performance, features, and usability.
• Our Answer - M.M.A
  Critical analysis of the electronic journal FAULTLESS, highlighting plagiarism issues and content quality. Discussion on the comparison with OBERON and other journals. Suggestions for improving FAULTLESS are provided.
• Our Response - Alex Noman
  Debate over the compatibility and capabilities of Scorpion and Profi computers with the ZX Spectrum. Critique of programming claims by Chung Software regarding outdated languages and methods. Discussion on operating systems like CP/M and iS-DOS in the context of their utility in modern computing.
• Our Response
  Exploring the varied interpretations of the term 'hacker' in Russian, highlighting distinctions and misconceptions.
• Hardware - Dr.Death
  Connection instructions for AY-3-8910 on Spectrum-compatible machines. Solutions for common audio issues in Russian computers. Advice for improving digital sound compatibility.
• Hardware - Dr.Death
  Discussion on modifying SCORPION ZS 256 for better performance, focusing on timing issues and TURBO mode. Explanation of improvements and potential problems with multicolors. Suggestions for further upgrades.
• Hardware - Poltergeist Corp.
  Analysis of hardware issues with Profi, a ZX Spectrum clone, focusing on INT signal problems causing graphic flickering. A solution is proposed involving a simple hardware modification. The author shares their success and the widespread adoption in Samara.
• Let's Gurm
  A microdrama illustrating the chaotic interaction between computer components during a printing task.
• Let's Feast
  Satirical story depicting an alternate reality where American culture and symbols are humorously twisted by Soviet influences.
• Let's Feast
  The story humorously describes Popov's efforts to help Papuans progress, amid desert struggles, political intrigue, and personal challenges.
• Let's Discuss
  Overview of military jargon known as 'Army Absurdities' collected by students, highlighting unique language and instructions used in military training and communications.
• Let's Feast
  Satirical article describing military humor and fictional military equipment.
• Literacy Campaign - Paul Atrides
  Analysis of hacker misconceptions and societal attitudes, exploring hacker culture's roots and ethical dilemmas.
• Primer - Paul Atrides
  Article discusses the role and activities of Russian hackers in the late 1990s, highlighting notable cases and categorizing different types of hackers. It covers the operations, risks, and impacts of hacking on international and local levels. The text also examines the societal perception of hackers and their portrayal in media.
• Contest - M.M.A
  A contest involving identifying songs from poorly translated lyrics, inspired by a radio segment. Participants guess the song and artist. No specific prize yet, but a free journal issue is promised.
• Contest
  A poetic reflection on personal struggle, misunderstood communication, and the burden of saving the world.
• Contest
  A poetic reflection on isolation and inner dreams, contrasting with harsh reality.
• Contest
  The article presents a poetic tribute to the community, emphasizing themes of unity, immortality, and strength through metal music.
• Advertisement
  Advertisement in Oberon magazine offers free publication and discusses available software, hardware, and stores related to ZX Spectrum.
• Advertisement
  Advertisement of computer repair and upgrades with pricing for various services. Options include drive connection, signal normalization, and memory upgrades. Specific services for different computer models like Pentagon and ATM.