Allow up to 16 DACs, by adding PCB 313A

2 files changed, 6 insertions, 3 deletions

diff --git a/device-functions.c b/device-functions.c
index 64feb6d..eeddd67 100644
--- a/device-functions.c
+++ b/device-functions.c
@@ -228,7 +228,7 @@ void Main_Rst (void)
 void set_dac(int dac, int word)
 {
 	/* allows dacs to be disabled (using dac=-1, for example) */
-	if ((dac >= 0) && (dac < 8)) {
+	if ((dac >= 0) && (dac < max_dacs)) {
 		globals.Registers.parallel_DAC_reg[dac]=word;
 	}
 }
@@ -4646,7 +4646,7 @@ void Main_update_shift_registers()
 	bus_setpin(out_STROBE_LINE, 1);		// latch the data
 	bus_setpin(out_STROBE_LINE, 0);		// release latch
 
-	for (i=0; i<8; ++i) {
+	for (i=0; i<std_dacs; ++i) {
 		/* load the upper-nibble latch */
 		bus_writebyte ((uint8_t) (Octal_DACportCS_high), (uint8_t) (globals.Registers.parallel_DAC_reg[i]  >> 8));
 
diff --git a/globals.h b/globals.h
index 9f13c6a..f9d83f1 100644
--- a/globals.h
+++ b/globals.h
@@ -294,8 +294,11 @@ unsigned long long ms_timer (void);
 
 #define max_gpib_input_length 512
 
+#define max_dacs 16	// total number of DACs, including extras on PCB 313A, if used
+#define std_dacs 8	// number of DACs on OP1B PCB
+
 typedef struct {
-	int parallel_DAC_reg[8];
+	int parallel_DAC_reg[max_dacs];
 	long shift_reg_out[num_out_SRs];
 	long last_relay_driver_settings[4];
 	int oper_enable_register;       /* for stat:enable command */