Everything fails eventually, but moving parts fail fastest of all– and optical drives seemingly more than others, at least in our experience. Even when they work, vintage drives often have trouble with CD-R, and original media isn’t always easy to find. That’s why it’s so wonderful that [polpo]’s RP2040 ISA card, the PicoGUS 2.0, now supports CD-ROM emulation.

We covered PicoGUS when it first appeared as an ISA sound card,  and make no mistake, it can still emulate sound cards for retro-PC beeps and boops. It’s not just the Gravis Ultrasound (GUS) from which the project took its name, but Sound Blaster 2.0, MPU-401 for MIDI, Tandy 3-voice, and CMS/GameBlaster are all soft options. Like most sound cards back in the day, PicoGUS provides game port support as well.

We don’t recall sound cards that served as CD-ROM controllers, but apparently, that was a thing before IDE became the standard for optical drives. We do recall old CD-ROM drives that shipped with proprietary driver boards, and PicoGUS emulates Panasonic’s MKS standard, which apparently did show up on some sound cards. For the end-user, that doesn’t matter much: once it’s all set up using the open-source utilities (and appropriate drivers), you’ll have an optical drive sitting at D:.

There’s a USB port on the PicoGUS that lets you use a FAT32 formatted USB stick not as a CD drive, but a CD changer. You can access multiple disk images from the drive, selecting them with the utility software. There’s even a feature that lets you automatically advance to the next disk by removing and reinserting the drive, which is invaluable for multi-CD game installers. It’s not super speedy: in USB mode, expect it to run as fast as a 4x drive. (2x if the PicoGUS is emulating a Sound Blaster at the same time.) Considering that’s all with a single RP2040 in charge, it’s pretty fast. For a DOS box, it’s probably period appropriate, too.

The Almighty Algorithm reminded us about PicoGUS in a video by [vswitchero], which is embedded below for those of you who would like more information in the form of rapidly flickering images and sound.