About the History of Cell Phones in Brazil The First Model Motorola Microtac Lite 2/DPC-650 and Factory Mode with Secret Listening

Learn about the History of Cell Phones in Brazil. Documentary Video with the DPC-650 and MicroTac Lite II models

    The year 1990 brought great changes to Brazilian cellular telephony. It was the beginning of everything, large-scale retail sales to the Brazilian population, since cellular telephones had existed since the 1970s and in the 1980s they were already used in many countries, even being seen in period films. Here, everything was still futuristic technology until the beginning of the 1990s, when Motorola finally brought its first models to Brazil.

    The first model launched in Brazil was the PT-550 (Microtac 9800X), but other models became popular in Brazil until gradually the price became more and more affordable. In the early 1990s, cell phone lines were very expensive, some were even worth more than the dollar or another dollar. Many people sold and resold lines as they do today with mobile devices. It was a completely different time from today, when the cell phone line itself is worth nothing!

    Then there were waiting lines, from months to years, it was really very difficult to have a telephone enabled in Brazil, and even more so, both the line and the model of cell phone were very expensive.

    In our telephony museum, we keep two cell phones from that time. The DPC-650 which was a simpler model, and the MicroTac Lite II which was much more TOP, "filled" with options such as a personalized MENU to choose the music tone and many other functions!

    The DPC-650 Has a Dot Matrix Display that show some little messages in Menu. But DPC-650 can´t receive or send SMS or other text messages! The Display is Only for Messages configuration!

Watch our Documentary Video about the First Cell Phones in Brazil! (Including the secret function test of wiretapping) Only Portuguese Audio version!

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Old 5 1/4 pol IDE HD Dock used in Old Servers and Computers. Museum ESIJMJG

IDE HD Drawer Dock used in old servers and computers. Product demonstration video. ESIJMJG Museum.

    Few old (vintage) products still survive the passage of time in conditions of at least being filmed/photographed, and even rarer are those that have their functional characteristics preserved. In the world of vintage computing, there have been countless parts/accessories created over the years, and since everything quickly becomes outdated (obsolete), it doesn't take long for them to become parts of electronic waste.

    Therefore, it is very rare to see this part that we show in the video below, it is a "Dock" Drawer for HD-IDE used in servers/computers from the 90s/2000s. 

Watch the video below and see what this rare but very practical and functional accessory was like for the world of vintage servers. (Portuguese Audio Only)

    This rack dock is very rare because today there are practically no more hard drives in the IDE standard, as well as motherboards that currently support the IDE bus are even rarer. 

    We believe that the IDE dock shown was used in many old servers, since it allows for quick hard drive replacement without opening the equipment (computer). Since servers are usually built into racks, having to remove them from their place, open them and replace a part would be a very costly and time-consuming task, which completely compromises a server's function (being operational to serve 24 hours a day)!

    A stopped server is an incalculable loss for certain companies, which is why the urgency of performing corrective maintenance is very important. We don't have time to open the computer, unscrew the entire structure to replace a hard drive! A 10-minute task that should be completed in 1 or 2 minutes at most!

    With this, this IDE HD Drawer allowed technicians to replace hard drives in just a few seconds. This is the main function of these devices created for the server world.

    A desktop computer would hardly have optimized parts to be replaced, since the target audience for desktops are home users, while the target audience for servers are corporate and more experienced users.

    A desktop computer can be stopped for longer for maintenance, while a server should only stop for the shortest possible time, since each second represents a strategic/financial loss for companies!

    With that, the entire server market should be focused on practicality and speed when it comes to maintenance.

    What impresses us is that this IDE HDD Drawer has an internal fan (disk cooling) and can be easily locked/unlocked by simply pushing/pulling its carrying handle (like a lock).

    A very well developed ingenuity.

    Although we can use this drawer on any desktop computer, rarely will it be used for the price.

    Of course, today there are versions of this drawer with SATA connection, but at the time the IDE was the best thing there was.

    Did you like it?

    Join us next time as we reveal other rare and classic items from our Museum of ESIJMJG IT!

JMJG
Electronic Eng.

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Tip Linux KDE in Notebooks,strange Like FN Key was Pressed directly. How to Solve it easily!

Notebook keyboard on Linux is strange as if the FN key was pressed directly. Is it a Bug? How to solve this easily.

FNis a Special Function key available only on Notebooks or special keyboards. Normally common Desktop Computer keyboards do not have this key. On some Notebook models the FN key is also responsible for activating the numeric keypad function (Num Lock) and with that, in some newly installed Linux operating systems users may encounter a very common problem. Typing on the keyboard and seeing that instead of letters, numbers are coming out, completely confusing the user.

Many people even try to adjust the Keyboard Layout in the Linux settings, but without success. That's exactly what will happen, because this is not the correct way to solve the problem!

So what can I solve? Is this a bug in my Linux? Should I install the system again?

Don't do this! The issue is not about a bug or defect in your Linux, the problem is that the Notebook must be configured for the numeric keypad (Num Lock) by default when the KDE session or others is being loaded!

The blame lies partly with the many Notebook manufacturers who still do not include the famous light bulbs in their keyboards LED

to indicate whether the Num Lock, Caps Lock and Scroll Lock functions are activated on the keyboard!

Desktop keyboards always have LEDs to indicate when these functions are activated, so the user remembers to turn off the functions when they are no longer needed. The same goes for Caps Lock (which always writes in uppercase letters). 

In the special case of Num Lock, the layout of the Notebook keyboard is usually differentand, except for some more expensive manufacturers, the Notebook keyboard does not have the right part of the numeric keypad, and therefore there is no space to embed the LED signaling lamps.

So we will show you how to easily solve the problem for the Notebook that is using Linux, and also "adapt" a reminder of the Num Lock and Caps Lock keys directly in Linux. Check it out:

1) Turning off the Num Lock function at the beginning of the KDE session or others, avoiding problems with wrong keys.

To temporarily solve the problem, the user can press the FN + NumLock key on their Notebook keyboard to turn OFF the NumLock function. NumLock is usually printed on the key with another function, so the FN key must be used to activate the NumLock function.

    As we can see, some letter keys also share numbers, J=1, K=2, L=3, U=4, etc. and with that, if the NumLock function is on, when we press the keys in their place the corresponding numbers will be printed on the screen, generating confusion.

To turn off the NumLock function at the beginning of the KDE session or others, access the Linux system settings and go to "Keyboard".

Click "Disable" on the Num Lock function at the start of Plasma. For those who use Gnome, XFCE, LXDE or other proscure the same option in the system settings (usually in Keyboard).

This way, every time we start Linux and enter KDE, it will automatically turn off Num Lock for us, avoiding the confusion we mentioned.

2) Installing an Aplet for simulate the Num Lock and Capslock LED

Even if our Notebook does not have the NumLock and CapsLock LEDs like a common Desktop keyboard, we can use other alternatives to do this.

In Linux using KDE and others it is possible to install an "Aplet" that reminds us about when the function is activated NumLock or CapsLock are on, showing messages near the clock bar.

To install in KDE you need to access the "Add Widgets" function

The procedure in detail can be seen in the video below, it works in KDE 4 or KDE 5 (Plasma 5). For other graphics managers, try installing them via the application or package center.

This way, your problem with typing letters and numbers will be solved, and the FN can still be used to turn on the NumLock function at any time you want, just remember to turn off the NumLock function to be able to type normally.

For Notebook manufacturers, the time has passed that even models with the most advanced keyboards compact, have at least 2 LEDs to indicate the NumLock/CapsLock function. The Scroll Lock function does not cause many problems so its LED can even be suppressed.

See you next time

JMJG

Eng Electronic/Desktop Linux Instructor.

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Know the Old 5 1/4 inch Floppy Disk Drives. New Original Sealed Box and a Little History about this Media!

Old 5 1/4 inch Floppy Disk. Unboxing Opening a NEW Original Sealed Box. Rarity. What were the first Digital Disk Storage Media like? Check out this Vintage Classic here! ESIJMJG EXCLUSIVITY!

    Before checking out a little history about Floppy Disks, watch this classic video. We did a sealed unboxing of a 5 1/54-inch floppy disk, one of the most used media in computers during the 70s/80s.

We did this to use these disks in our old computers (486/MSX), so don't worry, we didn't open the box for nothing! Of course, if it was closed, it would have more value for collecting, but what's the point of a closed box if we can't use it in our 5 1/4 units! kkkkk Practice speaks louder.

Check out this detailed unboxing of a sealed box of brand new 5 1/4 disks. ESIJMJG Computer Museum! (portuguese audio Only)

    It is not the first time that humanity feels the need to store information digitally. The first magnetic storage units were Magnetic Reel Tapes. After the invention of the Cassette Tape (K7) many devices were already being manufactured and became cheaper and easier to adapt to computers!

Thus during the 70s/80s cassette tape storage units (K7) became popular in personal computers such as the TRS-Color/TK/ MSX/ Apple II/ CP /XT/ AT/PC.

    But the tapes took a long time to store and even longer to find the information (you had to constantly rewind or fast forward)since the data was stored in a linear and sequential way!

    To solve this, engineers designed the Magnetic Floppy Disk (Floppy Disk) drives. The first Floppy Disk from the 1971s was 8 inches, huge/giant and could only store a maximum of 80Kb! That's right 80 Kilobytes! But this unit was too large to be embedded in personal computers.

    Later they reduced the size to 5 1/4 inches and the floppy disk had 160 Kb of storage, in addition to being able to be built into the cases of personal computers!

    Now that was a tremendous revolution!

    On a floppy disk, data is stored in a sectorial manner, in tracks, which can be quickly accessed by a mobile reader head, unlike traditional K7 tapes. This represented faster access and easier storage, which made floppy disks the most desired magnetic storage unit of the 70s/80s. But their price was very high! Few could have these units in their computers, and the K7 tape was still used in most computers.

    However, over time, floppy disks became popular and their price dropped so much that the use of K7 tapes was discontinued from computers and only floppy disk drives were being used in the late 80s and early 90s.

A Little History, 1970 until 1990!

    Nowadays, some text files in the Office suite take up more than 5 Mb, so it is not possible to store current text on these old floppy disks. However, in the 70s/80s, using DOS systems, a text file could be much less than 360 Kb, so there is enough space to fit text on these disks.

    But not only text, these disks were already used on a large scale for computers from the MSX/TRS/TK/CP line from Prológica and even the famous IBM-PC! At that time, personal computers did not have Hard Drives (Winchesters) because they were very expensive and used only in large company computers (replacing K7 Tape Recorders). Therefore, a 5 1/4 Drive was the only best option for storing files on personal computers from the 70s/80s, compared to K7 audio tape recorders!

    

The D.O.S (Disk Operating System) system was the most famous in the 70s/80s and long before Windows graphical systems became popular, "DOS" was the standard at the time, a system operated entirely by text, via command line (Prompt).

    At that time, computer users had to understand the system more technically, since there was no GUI graphical interface to help! For this reason, these systems were considered difficult to use and not all users liked using computers.

    Among the various DOS systems, the most famous and popular is MS-DOS (Microsoft) which came "bundled" with many standard AT-X86 computers.

    

    The most famous was the AT-286, simply called 286, which was soon evolved into the 386 and finally the 486 which was the most advanced 32-bit processor at the time. Even after the famous Pentium 1 (successor to the 486), 5 1/4-inch floppy disks were used in computers, but they were soon replaced by 3 1/2-inch disks and the 5 1/4-inch bay was soon occupied by the modern CD-ROMs that were part of the Sound Blaster Multimedia Kits!

    The First 8 inch Floppy Disk model, could store up 80 Kb Kilobytes! That's it! 80 Kilobytes! 

    The first 5 1/4-inch floppy disk models could store up to 160 Kb of information, using a Single-sided model. That's less than a text file in .TXT format today! But back then, that was everything!

    As floppy disk readers and, of course, the media itself evolved, high-density models emerged, in this case reaching the maximum that a 5 1/4 floppy disk can store.

    With the HD (High Density) floppy disk, we could achieve up to 1.2 Mb (Megabytes) of storage capacity. In the 70s and 80s, that was enough to store a few games, dozens of text files, and some software, but even by the beginning of the 90s, that capacity was already somewhat limited.

    As a result, it was common for users to have dozens of boxes with these 5 1/4 floppy disks just to store their information. At that time (1985) the Hard Disk was also quite popular and had much more capacity . Enough for MS-DOS systems or even Windows 3.1/3.11.

    But the 5 1/4 floppy disks were losing ground to another 3 1/2 (3.5 inch) floppy disk that was more rigid and allowed the HD version to store up to 1.44 Mb (Megabytes)! With practically the same price as the box, the 3 1/2 inch version was much more widely used and survived until the end of the 90s, when the famous CD began to be adopted in computers, thanks to the famous Sound Blaster Kits!

    And at this point is the End life for the Floppy Disk media and Drives... But here in the ESIJMJG they live forever!

ESIJMJG Computer Museum.

JMJG

Electronic Eng.

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Know the Old 3 1/2 Floppy Disks the old Store Units in Computers 1.44Mb of Space!

The old 3 1/2 Floppy Disk. The Old Storage Units. An Incredible 1.44MB of Space! Meet the grandfather of the flash drive!

Our private collection of floppy disks 3 1/2

    It sounds like a joke, but it's not. 1.44mb (a little less than a simple digital photo, taken with your modern cell phone camera), was the incredible amount of digital space, made available by this storage device, called a "3 1/2-inch floppy disk" or floppy-disk.

    For years, it has reigned as the most secure and reliable medium for storing digital data.

    "Floppy disks" have been used since 1960, initially they were 8 inches and could store only a measly 128kB, less than a typed text! After 1970, the 5 1/4 unit was developed with a capacity of 360kB! Then the famous 3 1/2 format of 720kB.

    With the high cost of hard drives at the time, floppy disks were the cheapest and most practical way for users to store data. Better than the old K7 tape drives (used as data storage for decades)!

    You could store your text files, games, images and even carry them with you in your pocket! Of course, all this because the old floppy disks were much larger than it, and stored much less capacity.

    The 5 1/4 floppy disks (360kb or 1.22mb HD) of space were very large, thin and without protection against dust or handling. These could not be put in a shirt pocket and taken out. In addition, they could easily be damaged, had to be kept in the box, and handled with much more care.

    But it wasn't always like this. The first 3 1/2 floppy disk drives were low density (DD) and stored only 720kb, only in the HD version these wonderful disks began to store 1.44mb (formatted)! In addition to the more compact format, the 3 1/2 inch floppy disks innovated in practicality. A hole on the right side determined whether it was DD (720kb) or HD (1.44mb), while on the left side, there was a safety lock, which could be manually activated to protect the recorded data. The old 5 1/4 floppy disks had to be covered with adhesive tape for this function.

    1.44 MB was a lot of space, enough at the time to store many files, and even an entire operating system (UNIX, MAC, MS-DOS or Windows 1.0)!

    Inside them, there was a magnetic media that was protected by a fabric (removed dust and dirt). On the outside, there was a protective cover, which could also contain labels to write the data content.

    It could be read by appropriate disk-drives (FDD) units. Thousands of computers between 1980 and 2000 had floppy disk drives installed. Pen-drives did not yet exist, which only became more famous after the invention of the CD-Rom.

    Due to the advancement of technology, in 1994 floppy disks were losing space, since they stored very little information, compared to CD-Roms (700mb) or pen drives (1Gb).

    With that, floppy disks were being abolished from everyday use in mid-2010, and many computers no longer had floppy disk drives built into the cases. Many users have been migrating their information to other media, and nowadays it is RARE to find someone who still uses them!

    RARE but not impossible! Even in the 21st century, many users in the world still need to use floppy disk drives. This is due to the limitations of some old programs, which still require running on DOS systems and being handled on floppy disks. For this, today there are floppy disk units that work via USB port.

    Our tribute to this device that is over 55 years old, and that was part of the lives of many, especially ours.

    Stay connected with us, soon many other curiosities and nostalgia.....

JMJG
Eng. Electronic

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The Old Computer Cases 286/386/486 and AT Standard and AT power Supply.

Remember the Old 286/386/486 Cases. Meet the old AT Standard computer power supply. 

    In the evolution of computers, the most remembered and acclaimed period in Brazil and perhaps in the world, will be the 80s/90s. The classic XT/AT 286/386/486 really were an unforgettable standard. So striking that some characteristics jump out at you, clearly identifying these computers. "I had an AT 286 at the time of 20Mhz with MS-DOS 4 and Windows 3.11, at that time computing was very technical and put the user in contact with the most intelligent electronic equipment ever manufactured in the century"  (JMJG)

The Video Bellow are in Portuguese Language Only (but in the future will be translated)

After watching the video, let's talk about some additional technical features.

The XT standard case was usually "lying horizontally" exactly like the first one, highlighting a super monitor on top of it, and its huge 5 1/4 units. The AT 286/386/486 standard case, on the other hand, was usually standing up (vertical) and had some striking features on its front panel.

1. The first one was the inclusion of a 3 1/2 disk drive, more modern and with greater capacity.
2. A window with a small LCD numeric display, which indicated the clock speed. At that time, computers needed to highlight their performance through speed. The AT 286 had speeds of 10 MHz to 36 MHz or more, and this was extended to the AT 486 standard, which reached an incredible 100 MHZ! Those who upgraded to the Pentium 1 and took advantage of the case could now change the numbers to 166 MHz or more!
3. It had the famous TURBO button next to the Reset button! This button is unique and only present in the X86 family (Pentium no longer had this function on the button, it was via physical configuration).
4. Some models had a key (with padlock) to protect the keyboard against unauthorized use (yes, at the time, the MS-DOS operating system and others did not have the password feature). This way, the owner of the computer could "lock" the keyboard to prevent strangers from using the computer.

    The Turbo Button was very important at the time for compatibility issues with XT (8088) processors that operated in the 5 Mhz range or less. With the AT 286 standard, processors had speeds ranging from 6 Mhz but the latest models already had 10 Mhz or 20 Mhz! This was a problem, because many Games and Applications of the XT standard were inherited to the AT and could be run normally, the problem is that developers used the processor clock (speed) as the basis for the application speed. So if a game for example ran "normally" on a 5 Mhz processor when it was executed on a 10 Mhz computer for example, it would become completely "unplayable - unplayable" because it would run very fast at twice the speed!

    To solve this in a simple way, the TURBO button manually toggled the processor speed, interfering in the clock base between the full value (Full Speed ​​Turbo) and exactly HALF (Slow Half Speed). Thus the user of an AT with 10 Mhz could run that game (XT 5 Mhz) just by turning off the TURBO, this would change the original clock of the machine to half, exactly 5 Mhz and the game would be fully playable again at normal speed! To alert the user to the speed of the machine, there was an LCD display that indicated the number in Mhz, if the Turbo button was pressed the Full speed in Mhz would be displayed, if it was turned off, the speed would be displayed exactly at half!

    That's what that unique LCD display on standard AT X86 cases was for!

As an option, there could also be an LED indicating TURBO ON/OFF or the LED with the writing HI/LOW, just to confirm the status of the Turbo button! It was a retention button, press to turn on and press again to turn off, it was not a pulse button like it is today in modern cabinets!

The standard AT Power Supplies were actually the first computer switching power supplies that existed, already used in the first PCs of the XT line.  In appearance they are very similar to the current power supplies (popular low performance), kind of square and with a classic fan for cooling.

But the AT power supply has big differences. 

• The On/Off button of the computer is of the retention switch type, press it once to turn it on, press it again to turn it off. It is quite large and has strong terminals, because in fact raw electrical energy flows through it. All this because the AT source must be turned on/off manually, that is, there is no way for it to turn on or off by itself! With this, the main difference from an AT source is that the on/off button on the computer panel is connected directly to the AT source and not to the motherboard as is currently done in the ATX standard!

• 
  The power connectors on the motherboard and the AT power supply are in the two-by-two 6-wire standard, known as P8 and P9. 

They are very similar, the technician can easily get confused and connect them incorrectly, burning the motherboard/power supply, causing huge damage! 

The right way to connect is to always leave the black ones together in the middle!

Therefore, although switching power supplies have greater advantages in size/weight/current than old linear power supplies, they still do not have any interactivity features with the operating system (automatically turn off, ACPI, suspend, hibernate, etc.).

I hope you enjoyed our trip to the past. The classics NEVER die!

See you next time!

JMJG

Electronic Eng

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The Power of Old Sound Cards Better Than the new onboard! Check this with Old Sound Blaster and OPL3 Yamaha!

Can the old overcome the new? Are old sound cards better than the new ones? Comparative Test see the results and be amazed!

Testing a Yamaha OPL3-SA3 Slot ISA (1990) in Linux Mint. Surprising!

Check the Test Result of an ISA Card with Yamaha OPL3-SA3 and TEA 2025B Integrated Amplifier! 

 

    Making Sound on a computer is something that has existed since 1951 (Ferranti Mark 1), when there was any record of it. Of course it wasn't a super HI-FI 3D Surround Dolby Digital, but... it was fascinating to have an electronic device reproduce its first musical notes at that time.

    Already in the era of the famous 286 (1984), computers already used a small speaker in their case. With this, games could reproduce soundtracks, many of them exciting, all this using beeps (distinct tonal frequencies). 
    Until then, this was the best available for computer SOUND. However, the need for more technology led to the development of the famous SOUND CARDS, which were plugged into computers as an accessory, greatly improving the user experience with digital music.

SOUND CARDS (The most famous)

    Sound cards had a dedicated "processor" that could provide better sound processing, as well as circuits capable of applying effects and filters to the audio signal, bass/treble adjustments, and MIDI music playback (those played by keyboards).

    In the 90s, the signs of "AdLib" and "Creative" with 16 bits, which transformed the computer into a true multimedia center. Some old games took advantage of these cards to play very exciting music and soundtracks. It was a really great improvement, which practically made the computer's internal speaker (8 bits) useless.

    Still in the 90s, Creative brought to the public its amazing Multimedia kits (Creative Sound Blaster). This kit included:

• 16-Bit Sound Card (with CD/ROM support+amplified output+microphone input,MIDI)
• CD/ROM (2X) + Game Titles on CD-ROM
• CD with Drivers for MS-DOS/Windows 3.11/95
• Passive Speakers (NO Amplification) with great acoustics for bass/treble

    This made any computer user crazy to buy it! Here in Brazil this kit was so successful that the term "Multimedia Kit" was used commercially to highlight computers that had this capability.

    In terms of SOUND, it was state of the art!

Yamaha OPL3-SA3 A151-A00 (Features and Technical Specifications)

    The A151-A00 (Addonics) is a 16-bit sound card, fully amplified! Powerful but still connects to theold buses ISA 16 BITS, typical of computers from the 90s. In the picture the 16-Bit ISA bus is black, and the famous PCI (more modern) is white.

    Fortunately the 16-Bit ISA bus is better than its old 8-Bit ISA! This board is more current and has superior performance, compared to the first generations of ISA 8-bit boards!

    This board was manufactured by several different companies (addonics, yamaha, etc.), which could add different functionalities to each one. Basically, it had a MIDI/Joystick connector, output for passive speakers, microphone input, line input (to connect radio, cassette deck, etc.).

    Electronically, they could have a different internal "layout", since each manufacturer could change the additional features a little.

    The Original board (OPL) manufactured by Yamaha itself, had all the basic features of the A151-A00 plus an excellent MIDI controller, internal connection for CD-AUDIO, and additional inputs/outputs. 

A151-A00 with CD-ROM Support

    Many old motherboards (80/90) did not yet have the famous controller for CD-ROM drives! This feature was provided by the sound card (from the Multimedia Kits), which had a 40-pin IDE connector, so that the CD-ROM control flat cable could be connected there. This way, the computer could read the CD-ROM via the sound card, and not via the motherboard! (in the photo, the CD-ROM connector is on the left corner).

    Cards external to the multimedia kits did not have this feature, and in this case only the sound could be increased (our test board).

The Yamaha YMF718- chip was the sound processor, using 16 bits.  It is also responsible for controlling the CD-ROM functions (when available on the board), compatibility with SoundBlaster, Adlib, WAV and MIDI resources, MPU-401. In addition, it could also add bass/treble control and the incredible 3D-Surround feature, making listening to music an unparalleled experience (even though the board is Stereo-2 channels).

    On Windows, the driver for this Controller is standard on Windows 95/98/ME and on GNU-Linux, the driver that was tested is the OPL3-SA3 already provided, just needing to be configured (Linux MINT/Ubuntu and others). On other systems, you should research support for OPL2-SA2 or OPL3-SA3.

    All the power of this sound card was due to the TEA2025B circuit, from ST, a STEREO amplifier chip, with an incredible 2.3W per channell! This could easily play passive speakers, loud and clear!

EXAMPLE of AMPLIFIERS WITH TEA2025

    The TEA2025B was originally used as an amplifier chip for AM/FM radios, including Tape K7, or any other portable equipment, since the chip works with a wide range of voltages (3V min and 12V max). The higher the voltage, the higher the power!

    It can still be connected in "bridge" mode, which will cause it to lose the STEREO function, but it will gain in power, the only one being up to 4.7W with an 8-ohm load!

    Due to the practicality of this circuit, it is used on a large scale, serving as the basis for amplifier circuits in many external speakers (even today).

    On the A151-A00 OPL3 board, this chip was already integrated into the board, and configured to use almost all of its 2.3W per channel! 

    Finally, the sound quality was reproduced in high-quality speakers (SBS30) from Creative, with fidelity, marking the presence of bass and treble with perfection above average. 

    As you can see, better, LISTEN, the sound quality of these old boards + passive speakers, is superior to the current kits. Not to mention thatToday's amplified speakers, for the most part, can't even reach half of this board!

    Today we have sound chips, built-in "onboard" but they are NOT amplified! Many of them also do not have 3D-Surround effects, not even a bass/treble control. 
    Only high-quality motherboards have better sound chips, but even then, they still depend on external amplification!

    Result: Yes, old sound cards can be better than new cards, even 32-bit ones, because here we are not comparing signal/sampling resolution, but rather resources and power!

    It can be better than 85% of the sound of Notebooks/Netbooks on the market, and 65% of the amplified speakers on the market.

For Windows 3.X Systems and D.O.S systems, follow the link to Download the Drivers, which are so rare to download

OPL3-SAX Driver Download for D.O.S

OPL3-SAX Driver Download for Windows 3.X

Drivers for Windows 9X (up to XP) are already built in so they should be automatically configured!

    He who has ears, let him hear this!

    I'll leave the TEA2025B datasheet for download, in case anyone wants to play with this chip (you can buy it or take it from another used equipment)

Download TEA2025b.pdf Information No MidiaShared 

    This way, electronics lovers, you can learn more about this fantastic integrated circuit, which was/is used in audio equipment, mainly portable ones.

See you next time.
JMJG
Electronic Engineer

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