C64 Gets A Graphics Upgrade Courtesy Of Your Favorite Piano Manufacturer

The Commodore 64 was quite a machine in its time, though a modern assessment would say that it’s severely lacking in the graphical department. [Vossi] has whipped up a bit of an upgrade for the C64 and C128, in the form of a graphics expansion card running Yamaha hardware.

As you might expect, the expansion is designed to fit neatly into a C64 cartridge slot. The card runs the Yamaha V9958—the video display processor known for its appearance in the MSX2+ computers. In this case, it’s paired with a healthy 128 kB of video RAM so it can really do its thing. The V9958 has an analog RGB output that can be set for PAL or NTSC operation, and can perform at resolutions up to 512×212 or even 512×424 interlaced. Naturally, it needs to be hooked directly up to a compatible screen, like a 1084, or one with SCART input. [Vossi] took the time to create some demos of the chip’s capabilities, drawing various graphics in a way that the C64 couldn’t readily achieve on its own.

It’s a build that almost feels like its from an alternate universe, where Yamaha decided to whip up a third-party graphics upgrade for the C64. That didn’t happen, but stranger team ups have occurred over the years.

[Thanks to Stephen Walters for the tip!]

39 thoughts on “C64 Gets A Graphics Upgrade Courtesy Of Your Favorite Piano Manufacturer

      1. They did make LCD. Atari Lynx uses Casio color LCD. GBC almost used Casio LCD but Sharp had a bit of temper tantrum because they’ve made custom chips and b&w LCD for Nintendo so Nintendo decided to go with Sharp in the end.

        I think Game Gear also used Casio.

  1. thing with these type of projects is where is the software

    hint! there is none, there’s a few demo’s on something no one will ever use or make… thats the problem with changing a standard to a 40+ year old platform … its neat that you can, but no one else will

  2. You can shove any graphics chip in an Atari cartridge or pbi port too

    With certain ones you might even be able to use anticto Dma data to it…with a software defined display list

    Or just use an avr chip like atmega8515 or 644, and create you own dma blitter (like on my custom 2600 sbc)

    Then no bottle necking from Vic and CPU clock sharing, and add 16k-32k of sram for video memory so it’s framebuffer is also separate and can run at the 21mhz of the avr, though the avr will need wait states or buffering to the display chips since those will run at 3.579454 or 4.43 mhz, with buffering and tri-state you can easily get around that, and while you wait each pixel clock would be around 6-7 clocks and for my CPU 18 clock per on CPU clock
    1,368 instructions per scanline in my case, much more than the 6502 76 per scanline

    Can do alot more graphics and sound using avr for dma, and 6502 for ay8910 and rest of io

    Or use the avr for game logic and sound(fast enough for some digital audio) and 6502 to also draw to screen, tri stating allows this flexibility but requires either an Atari custom 6502 or a 6502 with tri-state, or some 74 glue logic, which can be put on a single pld

    They can be over locked to 21.47727 mhz as these where used for sid chip replacements way back when, and ran around that speed, perfect for Atari systems since they work on harmonics of the color bust

    That’s why ntsc computer ran faster and had more colors than pal units

    And I feel bad for the secam Atari users, since the vcs graphics in france sucked with only 8 colors vs 128 on ntsc

    Even Jay miner couldn’t figure out secam: “good for color video, shitty for computer graphics”

    Hiding color data in between scaliness rather at the start of em and a complicated hue/color wheel encoding, ntsc and pal store color in phase shift of colorburst, the colors you can produce is a series of steps around a circle, either yuv, rgb/cmyk

    And color data (chroma) was separate of grayscale video data (luma)

    That’s why typically black and white TV can still show a ntsc color signal, doesn’t look for colorburst phase shift, but it can cause some picture distortion on older TVs, that’s why there was a color and black and white switch on those old consoles

    1. I could just slap an nes ppu or playchice-10 ppu and get RGB on my Atari 800 pbi

      Just add some dual port sram 8k is 4x the amount the ppu had and iirc can address more than that

      And get tile based bitmap pixel instead of buffered scanlines

      Though the Atari 800 can already produce better than nes graphics with scanline

      1. This is graphically what a c64 will look like

        You do have benefits of being able to run separate vram and Dma chip and still use the interal graphics chip (run a monitor or stub code to display realtime memory dumps and debugging monitor on a separate display, without too much impact or performance loss, since unlike antic or biltter, the avr provides modern full risc instruction set, and a few modern things like extra serial port, timers, and interrupts.. so combining a uart, full cpu core (32 8bit registers, avr iirc lets you do operations on any combo of em, not just just one accumulator, x,y flags, and program counter) ram, flash memory, eeprom (especially good for storing display mode in luts)
        pia/via chip in one 40 or 48 pin dip or plcc

        But you can do this on a stock Atari 8bit, and they have graphics chip upgrades that sit between the gtia and antic they provide more Amiga like and 16 bit style graphics

        https://youtu.be/jSS08co8zvA?si=f2wnRY22mOsB9z6l

        1. Just like no c64 fanboy gonna tell me sid was the best sounding chip

          This eventually became the sound of Yamaha pianos of the 1980s

          Those YM family of sounchips

          Sounds like Atari but with all the hardware filters and waveform manipulation of the sid chip, later with fm synth

          Still does everything in squares mostly but it’s cheap and using filters can get round that

          https://youtu.be/PK1hErnozbk?si=DvLzRgDX9A8BSCAy

          1. SID was the best sounding chip. That’s why it’s still used by professional musicians. I don’t hear much POKEY in mainstream music, probably because it generally sounded like crap with 4 8-bit channels as was commonly used. And while POKEY was limited, I don’t want to discount everything done with it. Some musicians have made amazing music with it despite its limitations. I went through a large archive of Atari music several years ago and developed a fondness for Grayscale (the group) and their constituent members music.

            Meanwhile on the C64…

            https://youtu.be/W9WCEMEwoww

            Don’t ask me why they used Hubbard tunes which were generally C64-first and sounded best there. Would have been cool to hear some covers of songs that originated on the Atari.

          2. Actually most professional musicians used YM Yamaha chips (sound blaster/Sega genesis)

            That’s what those hi end 80s synth piano keyboard with midi interface used mostly, and those used digital samples too.

            They had ibm PC and Atari st moneybags

            Sid chip was easily beat by an arcade machine soundchip

            This can easily substitute the additional pokey chip in a stereo pokey mod

            Pretty much the pokey can do a lot of what sid can do,

            I even can play games with digitized stereo sampled music on my Atari, use in dac mode play sid files too

            Pokey also sounds the same doesn’t matter if it’s Atari 400, Atari xl or xe

            Can’t say that about sid

            Different revision so no two c64 ever sound the same

            https://youtu.be/epALZ1dV_P4?si=2OP6yjoU3o0cSZ1i

            Sa1099 was available in around 1984 by Phillips iirc

            Pretty much a pokey on steroids with all sid capabilities and way more audio outputs

            https://youtu.be/CPwGaocgbHE?si=hrv62E_F3us9BbqN

  3. I had a C-64, and it did have quite a neet little graphics processor. It had a bunch of what were called sprites. Each sprite was a small bitmapped object, you could move around the screen. There were a bunch of other graphics processing features that were very cool on their own. The C-64 was a head of its time. It was a very cool little machine.

    1. The chip doesn’t support HDMI, so you’d need a seperate (probably expensive) NTSC -> HDMI converter. Otoh, the normal display output of the C64 is also NTSC, so you’d have a monitor available anyway.

  4. Anyone working on symbios operating system ? Seems to be mainly z80 based can we expect any msx2+ conversions for c64? What about video playback ? What about v9990 chip is it any better?

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