back to article Bored students can now enjoy Sonic 2 on TI-84 Plus CE calculators, thanks to port

Just a few weeks ago, Sonic the Hedgehog 2 was ported to the TI-84 Plus CE graphing calculator. Playing retro games on calculators is nothing new, with Tetris, Breakout, and even Super Mario Bros 3 having fan-made ports to Texas Instruments' popular calculator. However, no games featuring the blue hedgehog ever made it to the …

  1. Anonymous Coward
    Anonymous Coward

    There is no audio, but doesn't it still have the IO jack on it, plus USB (havent checked, the TI 84, none plus i have does), my TI 85 (RIP) only had the IO jack, and it could be used to output audio, you could just connect headphones to it. Some of the games that i installed on that had sound.

    1. Dan 55 Silver badge

      You might be able to make the I/O port drive stereo headphones but it looks like a bit-banging protocol which hogs the CPU so it would be difficult to play a game like Sonic at the same time.

      1. CowHorseFrog Silver badge

        the Megadrive has two cpus, one (Z80) which is resered for the sound chip.

  2. Dizzy Dwarf Bronze badge

    Graphing Calculator

    Still yet to find a decent graphing calculator for the iPhone/iPad.

    Thanks for the nostalgia.

    1. hedgie Bronze badge

      Re: Graphing Calculator

      Haven't found one (then again, haven't had the need to look), but for a retro calculator fix on iStuff, I've been using the "Retro 15C" app, for the old pre-suckitude HP RPN calculator. Cloned appearance and all.

  3. Blackjack Silver badge

    This was great, a shame it has no audio however.

  4. Bebu Silver badge


    Truly impressive. This programmer decided that he had the game's disassembly from a z80 based game console and a TI calculator based on the z280 processor - what could be easier? :)

    The greatest surprise is that he largely suceeded. These retro-coders are an intrepid, fearless breed (the nac mac feegles of the programming world. :)

    1. Dan 55 Silver badge

      Re: Heroic

      This seems as good a place as any to leave this ode to the Z80.

      (Later TIs have an eZ80 right?)

  5. CowHorseFrog Silver badge

    8/16 bit consoles dont have any acceleration of any kind, they dont draw anything to display. Its about layers, hardware sprites and playfields. Its just a matter of being fast enough to draw them all in the right order one by one.

    1. werdsmith Silver badge

      A hardware sprite is acceleration of some kind.

      1. CowHorseFrog Silver badge

        WHen i hear hardware acceleration i think that something is eventually drawn in some buffer. Hardware sprites of course appear on the display but they are never actually drawn anywhere into any buffer.

        1. werdsmith Silver badge

          Think of it as something that reduces the load on the CPU. Like a GPU does.

          1. CowHorseFrog Silver badge

            Technically sprites dont reduce load on the cpu, because to fetch the "data" to display still costs cycles of memory read. Nothing is free. Agreed a sprite is "faster" at displaying tits pixels than a cpu would be to draw them but thats not really acceleration as per my definition, because for something to be faster it means its faste rthan the old way.

            The MD CPU couldnt draw sprites into its buffer, and the sprite h/w never drew into the buffer as well, so you cant really compare as both were never drawing into a buffer.

            In the old days its this memory bandwidth that answers all hardware q.

            Want to know why the amiga had 8 sprites 16 pixels wide... its because there are only so many cycles in a raster line, and after allocating them to the raster, audio, and other dma, theres only so many left so we get 8 sprites of 16 pixels.

            1. ThomH

              Both the Master System and Mega Drive have dedicated RAM for their video display processors; it isn’t in the processors’ address spaces. Both therefore fetch and composite all sprites and backgrounds with absolutely no impact on the CPU.

              The Amiga might use a unified memory pool (at least for chip memory), but consoles generally don’t.

  6. David Austin


    On the plus side, the slowdown may help with the game's first boss, which was So hard on Game Gear, they removed the random ball height on the master system version. One of the meanest first bosses in all of Sonic History, especially on a 3.2 inch screen.

  7. Luiz Abdala

    That's why I love Sega, and dislike Nintendo.

    Sega used off-the-shelf CPUs, sound chips. Porting games from (Amiga, whatever) was 2 finger snaps away to a Sega platform. I bet the developers loved Sega for this. Dear lord, I saw a giant list of vintage computer games, and Sega had them all on their portfolio ported, ready to go, BECAUSE they used the Motorola 68k and the Z80, that these old PCs also used. Same CPU.

    Nintendo had a bespoke chip that they asked to Ricoh to build, based off a 65C816, that was named 5A22, and I'm talking just about the SNES. ( It was completely incompatible with the NES chip, which means all the developers have to learn how to code for that chip... but nobody has the SDK except Nintendo, because the chip is their thing. I bet a lot of devs gave up doing Nintendo games just on that.

    You need to send that for the developers to properly port and code their games for it...Nintendo keeps trying to reinvent the wheel when they think they are cutting costs, and end up making something more expensive. Typical.

    Sega realized after years that the hardware doesn't matter, as long you still play their games. They even emulate their own Mega Drive / Genesis games on Steam, no middle man. Nintendo, on the other side, keeps sending CDs and takedowns left and right, to anybody that even dares to play gamecube games on a switch or something.

    Nintendo, LET GO. Let people play their games wherever they want, how they want.

    Running Sonic 2 off a CALCULATOR is a slap on the face of Nintendo. No CDs in sight.

    1. CowHorseFrog Silver badge

      Re: That's why I love Sega, and dislike Nintendo.

      The amiga and sega had very different displays. For starters the amiga used bitmaps, while the sega was all "tiles". The amiga had 8 shitty sprites while the md had 80, which means a game was totally different in how and what it could draw. On the amiga basically everything was drawn into the bitmap display using the famous blitter, with the skinny sprites used a bit but again because they were so thin 16 pixels, you cant do much with just 8 x 16 when your screen is 320 or 640 wide. 80 Sprites is a completely different ball game.

      Yes they both had a 68000 but in games most of the logic is around preparing the hardware for dsplay, updating sprites, updating tiles for md, updating bitmaps using the blitter for the amiga.

      The shared logic between an amiga and md game is a lot less than you think, because most of the code in the game was not smarts it most was working the hardware.

      1. Dan 55 Silver badge

        Re: That's why I love Sega, and dislike Nintendo.

        Economics didn't allow it, but if more games of the time had targeted the AGA chipset (and its wider sprites) then there would have been far more possibilities, however game code would have been very specific to the Amiga.

        Alas, it seems real life has got in the way of the developer completing his modern-day SF2 A1200 port.

        1. CowHorseFrog Silver badge

          Re: That's why I love Sega, and dislike Nintendo.

          Nothing changes if we discuss AGA. The AGA was just more of the old ECS.

          THis is why SF2 for example on the amiga sucked and was done easily on the SNES and MD. The later had hardware aka lots of sprites which made it easy to move large characters around. Everything on the Amiga had a real cost, blitting large characters like in SF2 or FF, meant a lot of b/w was needed.. because the CPU has to read the data from the source, mask and write it into the screen, and then the screen reads its screen memory. On the SNES/MD its far easier, just move a few coordinates and sprite pointers to point to new data. None of this moving large amounts (compared to MD/SNES).

          THe game code for the two is completely different, because of these differences your program is completely different. We see this all the time when comparing MD and Amiga games, everyting is different. By everything i dont mean the graphics, i mean the layout of the game is different. Its the "same" game but its been redone completely from scratch for both systems. The enemies appear at different times, because the game engine itself is rewritten from scratch.

        2. CowHorseFrog Silver badge

          Re: That's why I love Sega, and dislike Nintendo.

          Im sorry but that YT video is trying to say the amiga could do the same as the SNES but its not true.

          OUr friend has carefully selected that stage and those characters for a reason. THeres a reason he couldnt pick fat characters, again because of performance, Honda is at least double the size and the poor Amiga wouldnt be able to move all that data. A much more busy screen say with Dhalsim doing his expando arms etc just wouldnt be possible.

          Back to my original thoughts, the code to blitter in all those is very different from the code thaat updates the sprite pointers on the MD. Like i said there is little code share between MD and Amiga, thats my point. You cant even share the joystick combo system because of the amiga only having one button.

          The Capcom arcade hardware is all tile based, theres a very nice book that analysis, and you will understand why capcom made its game that way, everythin gis targetting the machines strengths.

          1. Dan 55 Silver badge

            Re: That's why I love Sega, and dislike Nintendo.

            Remember his idea was to use a dual playfield with the players occupying the front playfield, so there's nothing to mask on this playfield apart from the other player where they contact. Also expando-arms are pretty thin.

            And if Dread (Doom clone) can run fine on the A500, which incidently the same person is also involved with, then I don't think you could write it off a modern-day SF2 port on the A1200 just yet.

            The best version for the Amiga in the 90s was Super SF2: The New Challengers and that worked with six-button CD32 pads.

            1. CowHorseFrog Silver badge

              Re: That's why I love Sega, and dislike Nintendo.

              Yes but dual playfields on a a500 is only 7/8 colours for each, while on AGA its only 15colors again this is just too limiting. He clearly chose Ryu and Ken because they share a lot of colours, whilst blank and anybody else would mean your playfield runs out of colors because 7 colors for blanka and 7 for the other player looks shitty.

              Yes Dhalsim's arms are thin, but they still cover a lot of "pixel space". Dhalsim + long arms is still twice as big as Ryu doing a dragon punch.

              Had a quick look at SF2 TNC for CD32, you can see a lot of compromises, for example theres no parallax scrolling of the floor. Everything looks rather blurry and pixelated.


              I ve seen a few doom clones for the amiga, but none are running fine on a 7M A500, they are all using 30MHZ+ 68030+.

              1. Dan 55 Silver badge

                Re: That's why I love Sega, and dislike Nintendo.

                The link in my other post shows Dread running on an A500 and it's pretty impressive for a 7MHz 68K computer. Compare with Doom on a 386 at 40MHz.

                The other SF2 game released for the Amiga in 1995 had a parallex background, but that had other problems...

    2. CowHorseFrog Silver badge

      Re: That's why I love Sega, and dislike Nintendo.

      the 65816is not that different from a 6502, they are very similar. If you look at the instructions they are exactly the same. THere are a few extras on the 65816 to support a larger than 64k memory space but itts still the same A/X/Y, the same LDA STA etc.

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