The TMS9918 is a video display controller (VDC) manufactured by Texas Instruments, in manuals referenced as "Video Display Processor" (VDP) and introduced in 1979. The TMS9918 and its variants were used in the ColecoVision, CreatiVision, Memotech MTX, MSX, NABU Personal Computer, SG-1000/SC-3000, Spectravideo SV-318, Spectravideo SV-328, Sord M5, Tatung Einstein, Texas Instruments TI-99/4, Casio PV-2000, Coleco Adam, Hanimex Pencil II, and Tomy Tutor. The TMS9918 generates both grid-based character graphics (used to display text or background images) and sprites used for moving foreground objects. The key features of this chip are, as highlighted on a 1980 presentation by Karl Guttag (one of the designers): 256 by 192 full color pixels per screen 15 different colors and/or shades Non-interlaced color composite video output Direct wiring to RAS/CAS type dynamic RAMS Automatic refresh of dynamic RAMS General 8-bit memory mapped type CPU interface CPU accesses RAM via VDP (no need for DMA) 32 dynamic characters per screen Thirty-two 8X8 patterns per row, 24 rows per screen Text mode with forty 6X8 patterns per row Multicolor mode with 64 by 48 memory mappable color squares External video input and control Single supply +5 volt operation Standard N-Channel silicon gate technology Product family All of the ICs in this family are usually referred to by the TMS9918 name, sometimes with an 'A' postfix. The 'A' indicates a second version of the chip which added new features, most prominently the addition of a bitmap mode (Graphic II). TMS9918 The non-A version was only used in the TI-99/4; the TI-99/4A and the other computers had the A version VDC. TMS9918A and TMS9928A The TMS9918A and TMS9928A output a 60 Hz video signal, while the TMS9929A outputs 50 Hz. The difference between '1' and the '2' in 'TMS9918A' and 'TMS9928A' is that the '1' version outputs composite NTSC video, while the '2' versions (including the TMS9929A) outputs analog YPbPr (Y luminance and R-Y (Pr) and B-Y (Pb) colour difference signals). The need for the latter was predominant in the 50 Hz world, including Europe, due to the different video signal standards PAL and SECAM. It was more cost-effective to output Y, R-Y and B-Y and encode them into PAL or SECAM in the RF modulator, than to try to have a different console for every different color standard. The '1' version also features an external composite video input which made it a handy chip to use in