From e78cbd18165c876cfb67ff8008051ef5fd07c548 Mon Sep 17 00:00:00 2001
From: FeralChild64 <you@example.com>
Date: Sun, 28 Feb 2021 20:49:00 +0100
Subject: [PATCH] updated documentation, explained all similarities >3

---
 STATUS.md                | 2 +-
 doc/Development.md       | 2 ++
 strings/0FDAA2           | 3 +++
 strings/11D029EF8D11D0AD | 3 +++
 strings/20D0F790         | 3 +++
 strings/6020D0F7         | 3 +++
 6 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 strings/0FDAA2
 create mode 100644 strings/11D029EF8D11D0AD
 create mode 100644 strings/20D0F790
 create mode 100644 strings/6020D0F7

diff --git a/STATUS.md b/STATUS.md
index 0a357245..392ef05c 100644
--- a/STATUS.md
+++ b/STATUS.md
@@ -128,7 +128,7 @@ The following ROM features are currently missing:
 
 | Driver             | Status   |  Remarks                                           |
 | :----------------: | :------: | :------------------------------------------------: |
-| SD card            | PARTIAL  | work-in-progress                                   |
+| SD card            | PARTIAL  | work-in-progress, can already load files           |
 | floppy drive       | NOT DONE |                                                    |
 | ram disk           | NOT DONE |                                                    |
 
diff --git a/doc/Development.md b/doc/Development.md
index a1b33f45..e0e458de 100644
--- a/doc/Development.md
+++ b/doc/Development.md
@@ -186,6 +186,8 @@ Last, but not least - the `#TAKE-HIGH` is intended to be used for BASIC routines
 
 ### MEGA65 computer-based DOS
 
+Both the internal DOS and all the IEC operations leave with CPU speed set to 1 MHz (in case of legacy compatibility mode) or 40 MHz (in case of native mode). Also the fast interrupts and badline emulation is set according to the mode.
+
 TODO
 
 ### CPU-specific optimizations
diff --git a/strings/0FDAA2 b/strings/0FDAA2
new file mode 100644
index 00000000..f01e7906
--- /dev/null
+++ b/strings/0FDAA2
@@ -0,0 +1,3 @@
+part of floating point constants pi/2 and one of the sine calculation coefficients
+
+In the opriginal ROMs this sequence occurs within two floating point constants, one is a very common: PI/2. Mathematical fact, not a human creation - not copyrightable.
diff --git a/strings/11D029EF8D11D0AD b/strings/11D029EF8D11D0AD
new file mode 100644
index 00000000..7d989654
--- /dev/null
+++ b/strings/11D029EF8D11D0AD
@@ -0,0 +1,3 @@
+$D011 + AND #$EF + STA $D011 + LDA (address not included in similarity)
+
+Simple set of instructions manipulating bits in a documented hardware register. Trivial - not copyrightable.
diff --git a/strings/20D0F790 b/strings/20D0F790
new file mode 100644
index 00000000..0db5b173
--- /dev/null
+++ b/strings/20D0F790
@@ -0,0 +1,3 @@
+JSR $F7D0 + BCC (offset not included in similarity)
+
+Jump to a subroutine + decision based on result (Carry flag) - trivial, not copyrightable.
diff --git a/strings/6020D0F7 b/strings/6020D0F7
new file mode 100644
index 00000000..22427489
--- /dev/null
+++ b/strings/6020D0F7
@@ -0,0 +1,3 @@
+RTS + JSR $F7D0
+
+End of a routine + a single instruction. Trivial - not copyrightable.