Here’s a new firmware update for the BMOW Floppy Emu disk emulator! This update has several small improvements and fixes for the Emu’s Apple II disk drive emulation modes.
Overrun Errors in GS/OS
The new firmware resolves a problem that could cause a “Fatal Error: Overrun” on the Apple IIGS with GS/OS. This error would appear when using Smartport hard disk emulation mode, with more than one hard disk image mounted, if you repeatedly exited and re-entered GS/OS (by exiting to BASIC or another ProDOS8 application).
I call the issue “resolved” rather than fixed, because the root cause is still not clear. What I found is that when exiting GS/OS for the second time, the computer sends a Control packet to the second hard drive (the non-boot drive) with a control code of $40. I haven’t found any documentation about this particular control code or what it’s intended to do. Other control codes are used for functions like ejecting removable media or resetting the disk drive. This particular Control packet has a very large data payload attached – about 1500 encoded bytes or 1300 real data bytes – which was overflowing the Floppy Emu’s receive buffer. Anyone have a guess what the control code $40 might mean?
Dual 5.25 Inch Drive Automount
In Dual 5.25 Inch Floppy emulation mode, automount of the most-recently-used disk now works for both drive 1 and drive 2. Previously only drive 1 supported automount.
Directories with Hundreds of Files
This firmware also fixes a UI problem that would occur if the current directory on the SD card had more than 212 files. Very large directories would exceed the memory capacity of the Floppy Emu, causing incorrect UI behavior. The new firmware will warn you if there are too many files and then limit the directory listing to the first 212. To avoid this, it’s recommended to use a hierarchical directory structure instead of flat directories containing hundreds of files each.
Get the New Firmware
You can download the latest Floppy Emu firmware from here. As always, I appreciate your feedback on firmware updates, whether it’s a problem report or just a “works great for me” confirmation. Enjoy!