Upcyling a 40-year-old Tandy Model 100 Portable Computer

The M100's LCD is really 10 separate displays, each controlled by its own HD44102 driver chip. The driver chips are each responsible for a 50-by-32-pixel region of the screen, except for two chips at the right-hand side that control only 40 by 32 pixels. This provides a total screen resolution of 240 by 64 pixels. Within each region the pixels are divided into four rows, or banks, each eight pixels high. Each vertical column of eight pixels corresponds to one byte in a driver's local memory.

The Tandy Model 100's odd display arrangement was done to make it considerably faster, but it does mean that modernising the hardware inside the M100 today can be a but of a challenge.