Figure 9-7. BASS sensor geometry 



BASS. The Tattletale IV is a 6303-based microprocessor that is pro- 

 grammed in BASIC. The operational sampling algorithms of the BASS are 

 programmed into random access memory (RAM), and it executes the routines 

 upon command. It is mounted onto one of the circuit boards of the BASS 

 electronics and direcdy controls the functions of the instrument. The serial 

 port of the Tattletale IV is the data output of the BASS as well as the interface 

 for programming and checking the RAM contents. 



In addition to providing timing for the system, which was later checked 

 direcdy against the WWV signature at PCI, the BASS program controls the 

 conversion and processing of the acoustic signals. The A/D converter of the 

 Tattletale IV is used to convert the final values prior to output, and a detailed 



Chapter 9 The Ohio State University Measurements 



167 



