Micomsoft’s XRGB-3 may not be as highly regarded as it’s successor, the XRGB-Mini Framemeister, but firmware versions 2.1 and later had a feature that its little brother did not; a ‘Low Resolution’ mode that outputs 320×240 (240p), and 640×400 (mid-resolution). Several shmups forum members reported that the XRGB-3’s 240p output looked pretty bad and not on par with some ‘gold standard’ downscalers of its time like the Extron Emotia and the Ultracade uVC. I wanted to see if there were any tweaks that could improve the 240p output and see if XRGB-3 owners should dust off their units to use them for downscaling to a 15kHz or 24kHz CRT.
Of the many input options, downscaling will mostly utilize the HD-15 port either by direct VGA or an external HDMI to VGA DAC. As these were made for the Japanese market, the 21-pin socket is wired for JP-21 (so do NOT input Euro-scart), and the D-Terminal requires an adapter to input component via RCA. RGBHV is output via HD-15/VGA, and will require a sync combiner to display on most RGB-capable CRT’s.
By setting ‘V Lock’ on and ‘Drawing Method’ to ‘Field’ in the OSD menu, 720p, 480p and 480i inputs have a very acceptable 18msec (1.1 frames) of lag.
Downscaling on the XRGB-3 is achieved by decimation which strips alternating lines of the source video, and is best suited for vertically integer line-doubled 240p content (games such as Sonic Mania, Bloodstained: Curse of the Moon). However, in order to also shrink the input horizontal resolution down to 320 pixels, the horizontal axis is also decimated, resulting in a lossy pixelated effect. Decimation therefore causes shimmer in both the X and Y axis which can be very distracting when there are repetitive patterns and textures in both 2D and 3D games. The Low Pass Filter (LPF) is practically essential to reveal some of the decimated details, though it is the lesser of 2 evils, as without the LPF there is offensive shimmer, and with the filter is bi-linear blur.
On the topic of blur, downscaling 720p video sources is way more hazy than a 480p input, which narrows down the XRGB-3’s use cases as a downscaler.
Compared side-by-side to the Extron Emotia (a line blender) and the OSSC Pro (another line decimator), the XRGB-3’s 240p output comes in last place. Looking at Crash’s gloves, it is easy to see that the XRGB-3’s vertical detail is crushed and blurred. The horizontal resolution suffers an even bigger blow, where what should be smooth outlines of Crash’s blue pants turns into staggered pixel art.
The HV image controls are otherwise fairly adequate to shift the video to offset the vertical and horizontal decimation in order to line up details to each scanline on the CRT. Separate HV controls can then move the post-scaled image which is a unique and convenient feature that negates the need for an external image shifter. There is also a 16:9 aspect ratio setting that letter-boxes the video which is handy for 4:3 CRT’s that do not have a 16:9 mode.
640x400p/24kHz output is disappointing. There is considerable horizontal underscan, and the decimation causes jagged stair-effect on linear details, and is not as high quality as the Ultracade uVC’s line-blended 24kHz output.
The XRGB-3’s blurry AND pixelated 240p output makes this hard to recommend as a downscaler to anyone who does not already own one. For current owners, this may be the gift that gives just one more time and may be worth checking out, though keep expectations low. It’s quirky, niche, and flawed, but if only casually downscaling, it might just work for your setup. For anyone more serious into downscaling, there are plenty more options to consider. See the video’s description for relevant links.