IBM Professional Graphics Controller
The PGC is an intelligent, accelerated 2D video card for the early PCs, marketed by IBM from 1984 to 1987. Screen resolution is 640x480, 256 colors from palette of 4096.
Firmware running on the onboard CPU (an Intel 8088) exchanges commands and results with the host via shared memory region; there is no direct framebuffer access. Acceleration is rather simple -- a single write to frame buffer may change up to 20 adjacent pixels in one scan line.
The card was supported by CAD software (AutoCAD 2.6j is known to work). CompuShow image viewer claims support, but fails to display anything (apparently, it was tested on a 3rd-party compatible card, with extended command set). Also supported by IBM Personal Computer Graphics Development Toolkit via VDI (virtual device interface) driver. A summary of firmware capabilities is documented on http://www.seasip.info/VintagePC/pgc.html and technical details are in the IBM Systems Journal article http://wayback.archive.org/web/20061015235146/http://www.research.ibm.com/journal/sj/241/ibmsj2401D.pdf.
MAME supports it as slot device "pgc" for ISA bus in ibm5160 (IBM PC XT) driver.
Public domain "IEA/ORAU Long-Term Global Energy-CO2 Model" software (DOI: 10.3334/CDIAC/ess.cmp002, https://cdiac.ess-dive.lbl.gov/ftp/cmp002/), using VDI driver for PGC to display its simulation results: