Schiller AT-102 Service Handbook page 132

SC(0..8)
SCINV
SO
SP..
SRAM
STRB1/2
SYSEN
TGATE
TM
TPC
TPCLK
TPD
TPDUR
TPCSEL
TPL
TPRES
TPS 0 & 1
TPTH
TS
TXD
uPOFF
U1,2,3,4
+UB
UCAS
UD1, UD2
UDS
UOE, USRAM
+UP
Annex
A.6
System control bus - CPU control signals
Screen inversion.
Serial output from the CPU to the ECG amplifier via opto isolators.
Spirometry control and data signals.
Static RAM memory.
Timing signals for printer control.
System enable - active when the Program Pack is inserted. The CPU will not work if
this signal is not active.
Gate pulse for programmable timer. This signal sets the TPDUR signal.
Thermal printer temperature - dc voltage from the print head, pulse width modulation
of signal TPTH.
Thermal printer clock. This is not a continuous clock signal but is active when
loading a line of printer data (into shift registers).
Thermal printer clock.
Thermal printer data - serial data for the printer.
Thermal printer duration - duration of the strobe pulse dependant on the ambient
temperature of the print head and the resistance of the print head.
Thermal printer controller select - control of thermal printer FIFO (input memory
buffer).
Thermal printer latch - print strobe control and data latch signal.
Thermal printer reset - FIFO reset for thermal printer controller.
Thermal printer strobe.
Thermal printer temperature - dc voltage from the print head to ADC, approximately
3.7 V at room temperature.
Temperature sense (from battery).
Outgoing serial data.
Off control signal. Logic 1 keeps the unit switched on, logic 0 switches the unit off.
Note that the unit is initially switched on directly from the ON key on the keyboard.
Upper LCD data.
Battery voltage.
Upper column address strobe (for dynamic RAM).
Upper data strobe - used for generating UOE and UWE.
Upper data strobe - used on the Schiller gate array.
Upper output enable - for static RAM.
Voltage rectified from the mains input and regulated to approximately +15 V.
AT-102 Service Handbook