TS440S.45 The following tests change internal signals. They are most useful if you are trying to trace the circuits controlled by these signals. You'll need a s service manual (or at least a schematic) to made reals sense of these. 23 Band select - all lines high 24 BAND select - all lines low 25 PD select - all lines high 26 PD select - all lines low 27 ENF select - all lines high 28 ENF select - all lines low 29 ENP select - a:ll lines high 30 ENP select - all lines low 31 RES select - all lines high 32 RES select - all lines low 33 CO select - all lines high 34 CO select - all lines low 35 AX select - all lines high 36 AX select - all lines low these next tests check the outputs of the 8255 parallel port interfaces, which select several internal functions. 37 (IC2) port A all lines high 38 (IC2) port A all lines low 39 (IC2) port B all lines high 40 (IC2) port B all lines low 41 (IC2) port C0-C3 high, C4-C7 low 42 (IC2) port C0-C3 low, C4-C7 high 43 (IC53) port C all lines high 44 (IC53) port C all lines low Following display busy lines and scan lines in the rightmost 9 digits of the display. You will push buttons to cause the digit to change from a 1 to a 0 indicating that the associated button has been pushed. test bit8 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- 45 LOCK AT Mic UP Mic DN PTT/AT VS1 46 (none) 47 (key scanner) 48 1 6 V/M VOICE 49 2 7 M>V RIT A/B 50 3 8 SCAN XIT SPLIT 51 4 9 M.IN T-Fset A=B dip3 dip4 dip5 52 5 0 CLEAR 1Mhz dip1 dip2 dip6 dip7 53 ENT DOWN UP dip8 dip9 dip10 (the digits 0-9 are on the front panel keyboard; dip2-dip10 are the segments of S50, the SSB frequency response dipswitch on the rear of the control unit printed circuit board.) 54 not used 55 not used 56 END