1200 2FD (250-3001) Math Coprocessor Faxback Doc. # 1975 There is a math co-processor socket on the main logic board at location U17 on the 5 expansion slot version of the HD, or location U3 for the 7 expansion slot version of the HD. Note: Refer to Faxback Doc. # 1259 for Main Logic Board Layout. Turn DIP switch #2 OFF of SW-1 to initialize the math co-processor. Note: Refer to Faxback Doc. # 9002 for Catalog Number of Math Coprocessor for your computer. Contact the nearest Radio Shack Store for the purchase of a 5 MHZ Intel 8087 Math Co-Processor. (smm/jej-05/11/94)