README: Add instructions for M1 macs and talk about the arm64 port.

diff --git a/README.md b/README.md
index f3c703be4ce5763ab2cdc82df23fb0dd68062690..4a746f0c95ebd3b9a8df8d6d92d94570c7867af6 100644 (file)
--- a/README.md
+++ b/README.md
@@ -38,6 +38,7 @@ build script:
 
 * Unix: `./build.sh update`
 * Windows: `build.cmd`
+* M1 macOS: `arch -x86_64 ./build.sh update`
 
 or download the correct boot image for your system from
 http://downloads.factorcode.org/images/master/, put it in the `factor`
@@ -48,6 +49,10 @@ directory and run:
 
 Now you should have a complete Factor system ready to run.
 
+Factor does not yet work on arm64 cpus. There is an arm64 assembler
+in `cpu.arm.assembler` and we are working on a port and also looking for
+contributors.
+
 More information on [building factor](https://concatenative.org/wiki/view/Factor/Building%20Factor)
 and [system requirements](https://concatenative.org/wiki/view/Factor/Requirements).