Dynamic Shift Registers - Bitsavers - Trailing-Edge

ROM Character GeneratorsMM4220N P/MM5220NP, MM4230NN/MM5230NN,MM4230NO/MM5230NO, 7x9 horizontal scandisplay character generatorgeneral descriptionThe MM4220NP/MM5220NP is a 1024-bit read-onlymemory and the MM4230NN/MM5230NN andMM4230NO/MM5230NO are 2048-bit read-onlymemories programmed to generate a font of 647x9 dot-type raster or horizontal-scan characters.The typical application shows the ASCII-addresssystem. The display refresh memory, built withMOS dynamic shift registers, and the TTL controltypical application7x9 Character Generator Systemtechniques are similar to those described in ApplicationNote AN-40. Designs for vertical·scan fonts,printer character generators, and designs for fontslarger than 7x9 are also outlined in AN-40.For full electrical, environmental and mechanicaldetails, refer to the M M 4 2 2 0 / M M 5220 andMM4230/MM5230 data sheets.3:3:~NNoZ."........3:3:(11NNoZ.."3:3:~NCo\)oz........3:3:(11NCo\)oz3:3:~NCo\)ozo........3:3:(11NCo\)oZo-r. •MM5230NN I. I• • •MM5230 NO I •.:MM5220 -----La NP•-r+ ...173