Changes

* [[Media:UM6845E-UMC.pdf|UM6845E]] by UMC

* [[Media:F6845.pdf|F6845]] by Fairchild

* [[Media:Mos 6545-1 crtc.pdf|CRTC 6545]] (MOS, Rockwell, Synertek) is pin-compatible with the 6845 and only has minor differences

* [https://github.com/hoglet67/BeebFpga/blob/dev/src/common/mc6845.vhd BeebFpga] [https://github.com/MiSTer-devel/Amstrad_MiSTer/blob/master/rtl/UM6845R.v MiSTer] [https://opencores.org/websvn/filedetails?repname=System09&path=%2FSystem09%2Ftrunk%2Frtl%2FVHDL%2Fcrtc6845.vhd OpenCores] Verilog/VHDL implementations of the 6845