diff --git a/rust-toolchain.toml.save b/rust-toolchain.toml.save
deleted file mode 100644
index f3201139..00000000
--- a/rust-toolchain.toml.save
+++ /dev/null
@@ -1,38 +0,0 @@
-// Tested for N=32; could be bugs in the loop bounds for other N
-// returns bytes written, like fwrite: N means no error, 0 means error in all fwrites
-size_t LongNumPrint( uint8_t *num, size_t N)
-{
-    // caller can print a name if it wants
-
-    const int revbufsize = 8192;      // 8kiB on the stack should be fine
-    alignas(32) char revbuf[revbufsize];
-
-    if (N<32) {
-        // TODO: maybe use a smaller revbuf for this case to avoid touching new stack pages
-        ASCIIrev32B(revbuf, num);   // the data we want is at the *end* of a 32-byte reverse
-        return fwrite(revbuf+32-N, 1, N, stdout);
-    }
-
-    size_t bytes_written = 0;
-    const uint8_t *inp = num+N;  // start with last 32 bytes of num[]
-    do {
-        size_t chunksize = (inp - num >= revbufsize) ? revbufsize : inp - num;
-
-        const uint8_t *inp_stop = inp - chunksize + 32;   // leave one full vector for the end
-        uint8_t *outp = revbuf;
-        while (inp > inp_stop) {        // may run 0 times
-            inp -= 32;
-            ASCIIrev32B(outp, inp);
-            outp += 32;
-        }
-        // reverse first (lowest address) 32 bytes of this chunk of num
-        // into last 32 bytes of this chunk of revbuf
-        // if chunksize%32 != 0 this will overlap, which is fine.
-        ASCIIrev32B(revbuf + chunksize - 32, inp_stop - 32);
-        bytes_written += fwrite(revbuf, 1, chunksize, stdout);
-        inp = inp_stop - 32;
-    } while ( inp > num );
-
-    return bytes_written;
-    // caller can putchar('\n') if it wants
-}