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Diffstat (limited to 'src/mess/drivers/tispeak.c')
-rw-r--r--src/mess/drivers/tispeak.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/src/mess/drivers/tispeak.c b/src/mess/drivers/tispeak.c
index 5bf841e7825..100fdd14e5c 100644
--- a/src/mess/drivers/tispeak.c
+++ b/src/mess/drivers/tispeak.c
@@ -18,9 +18,10 @@
#include "tispeak.lh"
// The master clock is a single stage RC oscillator into TMS5100 RCOSC:
-// C is 68pf, R is a 50kohm trimpot wich is set to 33.6kohm. CPUCLK is this/2, ROMCLK is this/4.
+// In an early 1979 Speak & Spell, C is 68pf, R is a 50kohm trimpot which is set to around 33.6kohm
+// (measured in-circuit). CPUCLK is this osc freq /2, ROMCLK is this osc freq /4.
// The typical osc freq curve for TMS5100 is unknown. Let's assume it is set to the default frequency,
-// which is 640kHz according to the TMS5100 documentation.
+// which is 640kHz for 8KHz according to the TMS5100 documentation.
#define MASTER_CLOCK (640000)