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ago 07 2014

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My Mega Drive III Tec Toy inside and sound samples

Did you know that not all are equal Mega Drive? And I speak not only of regional differences or obvious external differences between the Genesis and Mega Drive II models (called Genesis II in the US and Mega Drive III in Brazil), but of internal changes, PCB is (printed circuit board), whether the components.

PCB changes and internal components are nothing new, happen to all video games and other electronic. The reasons vary: lower costs, error correction, no missing components market, etc.

But what difference does it make to the player? You can make a beautiful difference, because the quality of picture and sound of the Mega Drive varies the internal components that were used. Both the first and the second model had several versions of PCBs and components that make a difference. Even a guide to differentiate the different versions already been prepared.

Those who follow the blog already know Skooter how to get the best picture of your Mega Drive using a SCART cable, Whichever version. In that article I ended up putting this video below to try to show how the image will:

Ended up a demonstration through nut because I have no HDMI capture card, so I had to shoot the TV screen, which certainly left the tarnished image. And the sound also, Although the main focus was not the sound, which apparently does not improve or worsens with use of SCART out, compared to a cable A / V traditional (compared with the RF cable naturally improves). But watching the video the Matheus Ferreira I noticed that the sound of my Mega Drive III seems to be better than the Genesis II which usually show the comparisons, and asked for a low part of the photo to see if it was a smaller PCB, characteristic of Genesis II who came later and had sound better than the first Genesis II.

Well, my Mega Drive III is 1993, and was with me in these 21 years. It is prior to the reduction of PCB Genesis II, then it should theoretically have a bad sound if the American Genesis II guide also applies to the Mega Drive III Tec Toy. The Brazilian Mega Drive has always had with identical to the American Genesis, only with NTSC system converted to PAL-M, which is only used in Brazil. But in the case of Genesis III to the external differences go a bit further. For example, RF door seems to be present only in the Brazilian version. In Japan, in Europe and the US televisions without A / V inputs they were probably already extinct in 1993 and Sega chose not to put a RF port. But in Brazil, always late, TVs without A / V input still predominated, reason Tec Toy should be chosen to include an RF port.

I figured that the inclusion of the RF port on the national model could be required to Tec Toy to redesign the PCB, so I decided to do better than just taking a picture of the bottom of my Mega Drive III. Since there are no seals, carefully removed some of my faithful companion screws 21 years and could expose her inner in favor not only of my curiosity, but also to give my contribution to the community that has for years unraveling the mysteries of the many versions of Mega Drive III.

The pictures below show what I found. The first surprise: Tec Toy made their own PCB. It is written: “Tec Toy VA0 171.6349C-10. Code 199.000.851.816. Prod. From. F. Manaus In. Bras.”. It is even strange to see a PCB made in Brazil. If it were nowadays, the chances are great that this PCB had been manufactured in China and the “manufacturer” national would merely put the Mega Drive already ready on packaging.

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0: SEGA 315-5660-02 FC1004 9320 STEP

Mega Drive III da Tec Toy, PCB VA0: SEGA 315-5660-02 FC1004 9320 STEP

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

Mega Drive III da Tec Toy, PCB VA0

O chip de I/O (IC6) brings entries “SEGA 315-5660-02 FC1004 9320 STEP”. This ASIC includes VM3438, Genesis II of the same audio chip that has poor audio, because melhorezinhos has the discrete YM2612. At first I imagined that the lower sound was due to the built-in YM3438 instead of discrete YM2612. But after found other information saying that the YM3438 is an improved YM2612, Top-DAC, and to version that Sega used is even better. So why, ironically, the sound of the first Genesis II is the worst of all? The explanation is that the chip has nothing to do with it, and to Blame it on bad amplification circuit that Sega used. There is even a mod (Tiido’s Crystal Clear Audio Mod) to let the Genesis II with the best possible sound in a Mega Drive.

Could Tec Toy had used an amplifying circuit better? Providing a sound also better? Or was it the TV audio captured by my camera that distorted the sound of my Mega Drive to the point it looks better? To take the course decided to call the Mega Drive directly into the line input of my sound card and do some recordings.

Unfortunately I could not make the catch optimally. As the closest TV from my PC has no HDMI input, took the SCART out and put the out A / V (composite and stereo audio video), connecting the video on TV and the audio on the PC, but it seems that the cable has a problem and the image appears not properly connecting this way. Only putting the audio cable also on TV is that it carries the video correctly. Probably there is a problem in the fabric of the video cable, or the ground is not properly connected it to the cable construction. The solution I found was to use a chaveador only as an intermediary. It should also put all the meshes (land) internally and so I could connect his video output on TV and the audio on the PC. As the PC is half away from the TV still had to use a P2 extender <-> P2 beyond the RCA cable -> P2, then it is possible that some noise or extra audio problem has been generated in this whole gambiarra.

In this test I used the same games from other video and also some games that have been compared to other videos on Youtube. And the result is in the video below:

Of course, Youtube compression may have caused changes, then also I leave a FLAC version with lossless compression:

The results are somewhat disappointing. On the one hand the audio of my Mega Drive III is not as bad as the Genesis II I've heard in some videos, on the other hand it is far from good as the Genesis model 1, to “High Definition Graphics”. And worst of all, my first Mega Drive was a Genesis model 1, com o High Definition Graphics, of those who came with RF and Sonic cartridge 1. Unfortunately he was eventually sold some years later to purchase a Super Nintendo. And that Genesis III I have so far won then 1993. In other words, I could have now a Genesis Model 1 with excellent audio, which is rare in Brazil since the vast majority bought the Japanese version that came in Brazil through Paraguay, and many others bought the version of Tec Toy. And probably still have the box in perfect condition, and still have the Mega Drive III.

Some other curiosities photos:

  1. In the pictures also appears the MDG-VA3424, which is apparently exclusive to the Mega Drive III Tec Toy, which to my knowledge is the only Mega Drive “Model 2” RF output.
  2. O chip IC1, with name “3C3 UA HD68HC000CP8 JAPAN” It is the main chip, Motorola 68000.
  3. O chip IC4, with name “SEGA 315-5676 9332KX001” It is the famous Z80, the coprocessor responsible for audio Mega Drive. The Z80 is the main chip of the Master System, which explains the perfect backward compatibility of Genesis with the Master System. Or almost perfect, but the imperfections are due to differences in the joystick.
  4. The two chips standing there (IC7 e IC8), I just failing to not take a picture showing the inscription, are the VRAM 64KB.
  5. The chips IC2 and IC3, with name “TOSHIBA TC51832AFL-10 JAPAN 9321HAK” They are the main RAM, do Motorola 68000, also 64KB.
  6. O chip IC11, with name “MB3514 9325 M37” It is RGB encoder.
  7. O chip IC5, with name “E9320 NMS64X8M10” It is the RAM of the Z80.
  8. The OSC1, with name “TXC-2 OSC 53.634 MHz T.Q.C. 3J” It is the oscillator (clock generator).

And to close: It will be worth looking for a Genesis Model 1 High Definition Graphics to have not only the best image of a Mega Drive, but also the best sound? Or is it better to settle for Kega Fusion that can provide even better sound and image, although not the actual hardware? I would like to know the views of readers who managed to get here. 🙂

About the author

Skooter

Skooter is a computer scientist and the founder of Skooter Blog. He is interested in everything related to technology and he likes to save money by making his purchases directly from abroad.

Permanent link to this article: http://www.skooterblog.com/2014/08/07/meu-mega-drive-iii-of-tech-toy-for-in-and-of-sound samples/

8 comments

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  1. 1
    Matheus Ferreira

    Valeu por ter pesquisado e tirados as fotos do seu Mega 🙂
    The audio is very good, better than many Genesis Model 2 Americans around. O chip do Master(PSG) It seems a little low, but I think it's just me. Although the audio is not as good as the Model 1, it has several advantages, as a direct Stereo audio output A / V(The Model 1 You need a mix of cable[Se for usar um Sega CD pro Stereo] or a stereo Y cable connected to the Phone output) and do not need a cable converter pro 32X. If you want a Mega with Sound Model 1 from the U.S., I think the Tec Toy Mega Drive II(Model 1 relançado pra conseguir dinheiro com o Sonic 1) é mais comum. Another thing, o controles do Master funcionam no Mega Drive e vise-versa. 😉

    1. 1.1
      Skooter

      Esqueci de mencionar no artigo, mas eu normalizei cada gravação para -1.0dB no Audacity. Fiz isso pois tive que deixar o ganho da entrada de linha em 50%, do contrário saturava. As it was very difficult to find the exact gain for the peaks stay in clippar not limit, I preferred to use 50% and normalizing each channel independently. In all cases increased little after normalization. But if the Master seem quieter is because it has a high peak too. Anyway the sound of the Master seems noisier and it is a different little noise early, I even stopped recording.

      I had not considered the issue of cables to connect accessories. I thought only the SCART cable, that is available for the Genesis 1 including plug P2 to get the stereo audio. And on second thought, it might be better to invest in a 32X or Sega CD instead of a Genesis. Also I had not thought in the Tec Toy Mega Drive II, despite that in his case it is necessary to check whether the Tec Toy made no Mega Drive II with the lowest PCB (equivalente ao Genesis VA7). The idea of ​​Genesis was also to have again the Mega Drive more played in my childhood. I'm sure he was a VA6, for he was a High Defintion Graphics and had TMMS.

      The problem is space to install all, My rack is already at the limit. Not to mention that 32X and Sega CD also has its own sources. And look who still wanted to have again an Atari 2600 e um Master System II da Tec Toy.

      As for controls, I have a Master System that use the Mega Drive in Master games. This compatibility also extends to Atari 2600, control of it works in Master and Mega and vice versa.

      1. 1.1.1
        Matheus Ferreira

        Just look dates, The Genesis is HDG 89, No HDG is 91, o Mega 1 BR is 90 e o Mega 2 é 91, however, o Genesis 2 was about to leave when the model without the HDG out, Tec Toy took a while, this leads me to believe they relaunched the Mega 1 Old as BR 2 to clear stock. Furthermore, there is a call source “Sega Power Trio” which is a 3-in-1 source pro Mega, CD e o 32x

  2. 2
    Matheus Ferreira

    Well, o Genesis 1 HDG came out in 89 e o Genesis 1 without HDG in 91, o Mega 1 BR came out in 90 e o Mega 2 On BR 91, however, o Genesis 2 It came out in late 91 / early 92, while Mega 3 BR left already 92, this probably prevented most of Mega 2 had the bad sound, because there is a short period of time before Mega 3, they probably relaunched the remains of Mega 1 BR como Mega 2 BR(Inclusive, o Mega 2 BR is the only “relaunch” of Genesis who continued with the printed message, os Megas JP, USA and EUR lost their “High Definition Graphics” as TMSS left and the bad sound appeared) to clear the stock and prepare pro Genesis 2 / Mega 3 BR as they did with the Master System and version “2” BR. A good idea would be to see if the Mega 2 BR tem a porta EXT, it would prove what I said once(Se o Mega 1 BR has also, é clear).
    Sobre o 32x e o Sega CD, there is a special font called “Sega Power Trio” to connect 3(Cloud, CD e 32x) all in one source only, cool to save space in the making.

    1. 2.1
      Skooter

      I think you're right. Also because Tec Toy was the need to keep the RF output, then they certainly needed some time to adapt, They may have launched the new PCB directly into the Mega Drive III.
      Anyway if I had to pick up another Mega I would prefer a Genesis Model 1 VA6 by the item nostalgia. Even found a Genesis Modelo 1 eBay no that seems to be exactly the same model that I had, in the box, with all accessories, including manual, Sonic in the box, fonte original, automatic switch with RF coaxial connectors 75 ohms (the Tec Toy that came with manual switch for tape 300 ohms), and adapters 300 ohms, both incoming and outgoing. All practically perfect, except for the price which is half PS4. 🙁

  3. 3
    DIEGO

    Face, You can put photo of the rear of your mega drive tb?
    Thanks

    1. 3.1
      Skooter

      Yes. I'm traveling now, but when I return next week I add the photo.

  4. 4
    HERBERTH DENNY

    Your post helped me a lot to buy a mega used to make my collection of their classics.

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