Custom Trs-80 and Other Mysteries

The Custom TRS‑80 and Other Mysteries contains eleven chapters and seven appendices. It covers electronics, circuit design, wire wrapping, soldering tips, software, and many other topics, along with discussions of software and hardware products available for the Model I at the time (1981). The book also has many Model I hardware projects for construction, including: a high-resolution graphics modification an interface to a paper tape reader an Exatron Stringy Floppy style storage device created from an 8-track tape player a hexadecimal keypad a hookup for an additional keyboard and video monitor a simple lowercase and reverse video modification a speedup modification for 2.66 MHz or 3.55 MHz operation a method for installing both Level I and Level II BASIC in the same Model I three different real-time-clocks, two with battery backups Chapter 5 contains the best description of the design problems with the Radio Shack Expansion Interface I have ever seen. Another interesting chapter is Chapter 11, titled "111 Cures for the Common Crash," which describes 111 (actually 112) tips for diagnosing software and hardware problems with a Model I.