First, a point of confusion needs to be cleared. The AST Research Inc. laptops 386SX/20 and 386SX/25 come with a default ROM font that today is known as Mx437 CL Stingray 8x19 (using int10h.org's naming). The int10h.org Mx437 AST PremiumExec is something different.

Stingray font

Rummaging through the interwebs for AST pictures, one finds a number of resources, such as a 2014-01-03 image by Tr3vor42532 and a 2014-01-03 video by Tr3vor42532, depicting a 386SX/20 1991 model with Rel. 1.06 BIOS. Further images indicate that the font has not changed in later releases. Follow the links for 1.05, another 1.06, 1.08 (Netfreak), 1.15 (EvieSigma), another 1.15, 1.16 (S. Pokorný). These all feature the same glyph forms. CL Stingray is recognizable from its unusual features involving a low-hanging bar in the 'A' glyph, and the “fat” 'x' glyph. In addition, the zero glyph '0' of CL Stingray has a slash, whereas Mx437 AST has a dotted zero(!). Trevor also showcases the ASTIVGA.COM program, which features a toggle between Expanded and Normal mode. While the resolution on the video is not great, my hypothesis is that the Normal mode corresponds to Mx437 CL Eagle II or Mx437 CL Stingray 8x16.

AST and MS-DOS

AST Research has published a version of MS-DOS 4.01 and version of MS-DOS 5.0 with a font of theirs in ega-ee.cpi, ega-nw.cpi and ega-se.cpi, in sizes 8×8, 8×14 and 8×16. The files 4201.cpi, 4202.cpi, 5202.cpi contain printer data and no screen fonts. The origins of Mx437 AST PremiumExec however trace to MS-DOS 6.0 instead, where there is an ega.ice file (CPI) with font sizes 8×19, 8×16, 8×14 and 8×8 and codepages 437, 850, 860, 861, 865.

Between IBM VGA 8x16/9x16 and ega-nw/437/8x16.fnt, there are only small differences. Some of the line drawing graphics and dingbats are one row or column larger. The dollar sign is actually shorter, the 'J' is wider, the 'O' is round like EGA.CPI, the accent grave is straight, 'b'/'d' has a serif, diaeresis are two rows high.


Difference image VGA8x16 vs. AST8x16. Red: present in VGA only. Green: present in AST only.