The ROMs for the MC1702 in pc.cpp were marked BAD_DUMP not too long ago (https://github.com/mamedev/mame/pull/11390), because some of the characters in the integrated font show corrupt pixels.
During a recent conversation with @Xolod he mentioned that the MC1702 is actually the PC compatibility board for a Soviet clone of the DEC Professional 350.
The ROM archive he sent contains the ROMs for the host machine as well as the MC1702 compatibility board (all uploaded). Unfortunately the MC1702's ROM shows the same corruptions in the font as the existing one plus other differences.
@Xolod promised to be on the lookout for other boards to compare - maybe the original source for the characters was already corrupted (paper tape?), or the EPROMs are fading in a peculiar pattern.
The Hyundai Super 16 T comes with a comprehensive test suite - and Gary.
BTW, text attributes test on ibm5170 broke recently (light colors are not displayed anymore) -- I suspect ad7cbf9c0a1d888d28d70b2c29c20350592482e0 was the reason.
Distant memories of my 2 MB ViRGE topping out at 800x600 with 24-bit color depth, not 32-bit, and being able to count the number of Windows-based emulators that actually supported 24-bit on one hand - MAME being one of them.
Most emulators were designed solely around 32-bit graphics (with 16-bit fallback) and would either tell you the display depth was unsupported, or simply error out and/or crash on load, if not taking out the entire PC with them (the joys of Windows 9x vs. NT).
For the record, MAME 0.106 was the last version to support 24-bit displays.