*This question is derived from this [Board review thread](https://electronics.stackexchange.com/questions/163641/board-review-is-this-pic16f877-rs232icsp-board-correct-robust), I thought it would be preferable to make it a standalone question.*

I want to be able to reset a PIC remotely using the only communication port of the board, the RS232. But I also want to be able to program it using a ICD3 (no bootloader), and this programmer apparently applies high voltage (0-13V?) to /MCLR which will certainly kill the MAX232 (MAX233 in fact). 

Would a schottky between R2out of the MAX233 and 5V be the way to go? The datasheet says that the absolute maximum voltage on that pin is 5.3V, I find it a bit tight for a schottky. Any more robust suggestions? I don't want to use a jumper as this could be forgotten... 

Schematic:
![enter image description here](https://i.stack.imgur.com/TYiFm.png)

Thanks

Edit:
-----

Will this work?

![schematic](https://i.stack.imgur.com/qOanY.png)

[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2fqOanY.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)

The Zener is a [ON SEMI BZX84B5V1LT1G](http://uk.rs-online.com/web/p/zener-diodes/6878174/) that has 5-5.2V tolerance at 5mA and I'm allowing 4.4mA max. The MAX233 will drive the /MCLR pin at 0.41V where up to 1V is a low level. The 20kOhm pull up comes from one of Olin's answers [here](https://electronics.stackexchange.com/questions/31507/icsp-circuit-vpp-13v-and-vdd-5v-on-pic-microcontroller-mclr-pin).