Update docs

README.md

@@ -85,14 +85,17 @@ to see what it can do) on a classic RC2014. Highlights:
 
 * Extremely flexible: this is not an OS, but a meta OS. You build your own OS
   through glue code.
-* 2K binary (but size vary wildly depending on what parts you include. 2K is for
-  a shell using all parts)
+* 2K binary (but size vary wildly depending on what parts you include. 2K is
+  for a shell using all parts).
 * Built with minimal tooling: only [scas][scas] is needed
 * Can read and write to memory through shell
 * Can run arbitrary routine from arbitrary address with arbitrary arguments
   from shell.
 * Can "upload" code from serial link into memory and execute it.
 * Can manage multiple "block devices"
+* Can read SD cards as block devices
+* A z80 assembler written in z80 that is progressing well and should soon be
+  able to replace `scas`.
 
 ## Organisation of this repository
 

doc/load-run-code.md

@@ -58,6 +58,21 @@ So, we'll expect this to become `62` after we run the code. Let's go:
 
 Success!
 
+## The upload.py tool
+
+The serial connection is not always 100% reliable and a bad byte can slip in
+when you push your code and that's not fun when you try to debug your code (is
+this bad behavior caused by my logic or by a bad serial upload?).
+
+To this end, there is a `upload.py` file in `tools/` that takes care of loading
+the file and verify the contents. So, instead of doing `load 8` followed by
+your `cat` above, you would have done:
+
+    ./upload.py /dev/ttyUSB0 tosend.bin
+
+This emits `load` and `peek` commands and fail appropriately if the `peek`
+doesn't match sent contents. Very handy.
+
 ## Labels in RAM code
 
 If your code contains any label, make sure that you add a `.org` directive at