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Any Programmers Here Worked On Official Sega Genesis Games In 90's

Discussion in 'General Sega Discussion' started by cokyen, Jul 15, 2016.

  1. cokyen

    cokyen

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    I want to ask some questions for anyone here who worked on official Sega Geneiss Games in the 1990's as part of their career. NOTE: I figure engineering. / reverse engineering. Would be not proper on topic for this as I am not asking. Implementation questions . HOWEVER please move it wherever you feel it best fits please.


    What game(s) did you work on?

    Did you all build your own tools for the game like a sprite editor , tile program , vdp debugging tools, z80'sound debugging tools , or your own debugger for steppin into code like modern IDEs


    What language did you use to write the tools . High level (- c c++ or low level - assembly

    How was it different for you writing a game in assembly compared to later games developed in c c++
     
  2. GerbilSoft

    GerbilSoft

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    I'll answer a few of these, since I don't think anyone currently active on the forums was programming for the Mega Drive professionally in the early 1990s.

    • The vast majority of Mega Drive games were written in assembly language. A select few were written in C (e.g. Sonic Spinball). None that I know of were written in C++ due to the language being rather immature at the time.
    • Typically, games were debugged using a close-to-retail system with an in-circuit debugger fitted on the 68000 CPU. This allowed single-stepping the program with a debugger on a PC while still running on hardware. (An ICD was also available for the Z80.)
    • Sega used something called the "Digitizer" to draw tiles. This system had a drawing tablet and some other input devices. The resulting files were then converted into Mega Drive format using an NEC computer (possibly PC-98 architecture?). I'm not sure if third-party developers used this, especially in the US where PC-98 wasn't really a thing.
     
  3. cokyen

    cokyen

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    First , thanks for you time, GerbilSoft. We're the debugging tools they had better than most debugging capabilities of emulators we use nkw toda? Also are their free programs that allow stepping into with m68k for the Geneiss? Lastly did the liscense from sega come with alll the neat tools as part of the package? Ie the circuit board for debugging etc.

    Thanks again !!

    -Chris O
     
  4. GerbilSoft

    GerbilSoft

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    I can barely understand what you're writing here. Can you please take the time to use correct spelling and grammar? (Most browsers nowadays have built-in spell check; Firefox is underlining many of the words in your post.)

    Anyways:
    • Emulators as they exist today weren't a thing in the early 90s. You couldn't run a Mega Drive game on a PC to test it; you had to use actual hardware with an EPROM board.
    • There are some emulators that allow single-stepping on the 68000, such as Regen and I think Exodus. For actual hardware debugging, you'd need to get a 68000 ICD, which might still be available on eBay but I'm not sure.
    • I have no idea how the Sega license was set up. Remember that the Internet wasn't really a thing back then, so you had to order the software directly from Sega instead of downloading it from a website. Sidenote: A lot of the development hardware was actually handled by third-party companies, e.g. Cross Products. For an example, see Sega_Mega-CD#Cross_Products_SNASM_Mega_CD.
     
  5. cokyen

    cokyen

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    Thanks again, sorry for bad grammar . It's partly due to the fact that I'm using a iPhone and I'm rushing to respond in timely manner. I heard a reply about bad grammar and off topics on another thread I made. Is that warning for me? Are the two threads I've made stepping out line of rules? How can I correct if so?