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Jeff Parsons 2015-12-10 15:38:25 -08:00
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_posts/2015-06-01-debugging-the-ibm-vga-rom.md
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The IBM VGA ("Video Graphics Array") standard was introduced as part of the IBM PS/2 line of computers;
it was not a feature you could purchase or install in older PC, XT or AT-compatible machines. In fact, full VGA
support was not even available in all PS/2 models. Of the first four PS/2 models -- the 8086-based Model 30, the
80286-based Model 50 and Model 60, and the 80386-based Model 80 -- VGA support was available only in the three
higher-end models. The Model 30 came with MCGA ("Multicolor Graphics Array") video hardware that supported a subset
of VGA modes (eg, 640x480 2-color and 320x200 256-color graphics).
support was not even available in all PS/2 models.
Of the first four PS/2 models -- the 8086-based Model 30, the 80286-based Model 50 and Model 60, and the 80386-based
Model 80 -- VGA support was available only in the three higher-end models. The Model 30 came with MCGA ("Multicolor
Graphics Array") video hardware that supported a subset of VGA modes (eg, 640x480 2-color and 320x200 256-color graphics).
It wasn't until October 1987 that IBM finally introduced an 8-bit ISA card that brought VGA capability to older PCs.
The card was called the **IBM PS/2 Display Adapter**. However, I think the name is a bit confusing, since the card