Quote:
Originally Posted by SiriusHardware
On that one, chip select pins 18, 20, go to 0V and pin 21 to +5V. Power supply pins are pin 12=0V and pin 24=+5V.
As pin 18 is a chip select rather than A11 on that IC, that suggests it is a 2K ROM, so reduce the max read address to 2048 and don't connect the A11 output from the Mega / Pi to pin 18 on the PROM.
|
Apologies for the daft question. How can I tell from the schematic that pin 21 is +5V?
And how can I tell from the schematic that 12,18 and 20 are different? They look connected to my untutored eyes and look like they all go to Ground...
Colin.