Update docs

examples/chapter10_08/readme.md

@@ -2,7 +2,7 @@
 ## External SPI RAM and Computing 10,001 Digits of Pi
 
 <p align="center">
-    <a href="https://godbolt.org/z/Wsrd4bdKh" alt="godbolt">
+    <a href="https://godbolt.org/z/EMx88ocxn" alt="godbolt">
         <img src="https://img.shields.io/badge/try%20it%20on-godbolt-green" /></a>
 </p>
 
@@ -65,7 +65,7 @@ A similar implementation of the Pi Spigot program has been setup
 at [godbolt](https://godbolt.org), where it can be compiled and executed.
 This setup computes $10,001$ decimal digits of $\pi$.
 
-Use the following [short link](https://godbolt.org/z/Wsrd4bdKh)
+Use the following [short link](https://godbolt.org/z/EMx88ocxn)
 to further explore this program.
 
 ## 8-Bit MCU Adaptions

readme.md

@@ -374,6 +374,13 @@ The MICROCHIP(R) [former ATMEL(R)] AVR(R) configuration
 called `target atmega2560` runs
 on the ARDUINO(R) MEGA compatible board.
 The program toggles the orange LED on `portb.7`.
+At the moment, the environment and build for this
+target is set up for $64~\text{kByte}$ program code.
+If the fully available $128~\text{kByte}$ code space
+needs to be used, then adaptions to the compiler,
+linker, startup-code and interrupt-vector table
+will be necessary. For this potential adaption, see also
+(issue 593)[https://github.com/ckormanyos/real-time-cpp/issues/593].
 
 The MICROCHIP(R) [former ATMEL(R)] ATmega4809 configuration
 called `target atmega4809` runs