Some good suggestions from Zac67 regarding the memory, certainly worth checking all of the ZIPs are the same. More information
here.
The Diode for the CR2032 Battery is preferred as a 1N914 although the 1N4001 should work the both have the same VF Characteristics, although the IN914 is the recommended item according to some of the Amiga battery hack files.
As for the RTC backup power supply; you're far better off using a small signal Schottky diode as opposed to a standard silicon diode (e.g. 1N914, 1N4148, 1N400x, etc).
To look at the maths behind it...
From the
RP5C01 datasheet we can see the minimum input voltage is 2.2V at a current of 15µA. The RTC has a 1.2k Ohm resistor in series with the battery (see
schematic). So it'll develop (1.2k x 15µA) = 18mV, or round to 20mV across it. So the actual minimum voltage at the RTC becomes (2.2V + 20mV) = 2.22V
If a
1N914 diode was used, we can see it has a forward voltage drop of around 0.55V at 15µA. So it'll only provide a clock backup until the cell reaches a voltage of (2.22V + 0.55) = 2.77V. The CR2032 cell is 3V nominal, meaning it only has to discharge by 0.23V to a terminal voltage of 2.77V before it'll need to be replaced, so that's using well under half of the cell's capacity.
If a Schottky diode was used instead, say a common
BAT85 for example, we can see the forward voltage drop will be less than 0.24V at 15µA. So the cell can discharge further to (2.22V + 0.24) = 2.46V before it needs to be replaced. You still won't get to use the full rated capacity of the cell (230mAHr), but at a guess you'd still get about 60% of that (140mAHr). At a current draw of 15µA, I'd expect a clock backup time of 389 days or 13 months. Of course that depends on the exact cell being used, age/condition of the cell, exact current draw of the RTC on standby and the temperature.
So in summary, while the silicon diode will work, you'll get far longer out of the coin cell if you use a small signal Schottky diode.
