summaryrefslogtreecommitdiffstats
path: root/system/atari800_os++/README.atari800
diff options
context:
space:
mode:
Diffstat (limited to 'system/atari800_os++/README.atari800')
-rw-r--r--system/atari800_os++/README.atari80023
1 files changed, 23 insertions, 0 deletions
diff --git a/system/atari800_os++/README.atari800 b/system/atari800_os++/README.atari800
new file mode 100644
index 0000000000..1d03af498d
--- /dev/null
+++ b/system/atari800_os++/README.atari800
@@ -0,0 +1,23 @@
+
+This copy of OS++ has been slightly modified to allow it to work with
+the Atari800 emulator. Specifically, Atari800 patches the operating
+system ROM to support high-speed emulated disk I/O. Unfortunately,
+when this is done, OS++'s checksum routines correctly detect that the
+ROM checksum doesn't match, and the OS doesn't start.
+
+The *correct* way to fix this is to make Atari800's ROM patch actually
+update the stored checksum after patching. For Atari800 2.1.0 and
+previous, the workaround is to replace OS++'s checksum calls with NOPs,
+which is what's been done to this copy of OS++ (future versions of
+Atari800 will hopefully have proper support for OS++)
+
+Note that OS++ only works correctly with Atari800 if the emulator's
+high-speed SIO patch is enabled. Without the fast SIO patch, OS++ can't
+read the emulated disk drives. Most likely, this is due to Atari800 not
+emulating the hardware 100% perfectly.
+
+Also, this is documented elsewhere, but worth a mention here, too: OS++
+does not include BASIC! Machine language programs normally don't call
+the BASIC cartridge, so they will be unaffected. If you want to be able
+to run BASIC without using the copyrighted Atari BASIC ROM, try the
+excellent public domain Turbo BASIC XL.