In no particular order.
This is the original #IBM #CGA board I modeled my clone after. I bought it as broken, but did not care much as I just needed measurements and to clear up some part of the schematics.
Turns out the issue was only a scraped trace on the backside, that shifted and touched a nearby via.
This #repair was just dumb luck.
Time to order some more #prototypes
This time it's another #soundcard with an ES688 plus a real #OPL3 onboard and something a bit more trivial: a small #MIDI #synth with a #SAM2695 that plugs on the joystick port.
There are already similar projects, but I wanted one that was relatively easy to solder with my instrumentation (and also wanted to experiment).
I should really repair my Commodore 1084 for these tests, but for now this sucky #fleamarket flat TV will do.
I'm going to design another revision of the #CGA Redux card, so that it can be built with the "old" style composite output without having to cut traces. This will allow less saturated colors from the composite output.
The idea is to allow people to build the card with the output style they like.
Sorry for the colors that might be a bit too vivid, but I used a composite->vga converter that is old and crappy.
I've updated the repo with the results https://github.com/hkzlab/CGA_Redux
I also need to replace the 74LS174 I used with proper 74S174, like on the original board. I also need to swap the VRAM with chips that have at least 120ns as access time. The current ones are at 150, unlike my original.
for two years i've been developing a project known as MegaGRRL. it's a portable sega genesis music player that uses the original sound chips, and plays VGM files from an SD card.
the portable version is still in development, but recently i designed a simplified, desktop version of the player, and i'm happy to announce that the schematic, PCB, firmware, and 3d print design files for MegaGRRL Desktop are now available for anyone to build.
if you're an FM synth nerd or just a fan of chiptunes, check it out!
longer demo video on youtube: https://youtu.be/fPXrVPKKeYM
hackaday.io page: https://hackaday.io/project/169129-megagrrl-desktop
world wide web site: https://kunoichilabs.dev/megagrrl_desktop.html
It's interesting that the Micro8088 misdetects it (it says that there is a video bios present). But it does absolutely the same thing with the original card I have here.
Keep in mind that this board is still undergoing basic testing, but I had joystick / FM / Digital audio working just fine on my 286 test machine.
Will install it in my Micro8088 build later/tomorrow.
In no particular order.
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