Ta dah! I thought it couldn’t be done, but I used my hammer and tongs to smash HD20 emulation and floppy emulation into a single firmware version. No more re-flashing the board when you want to switch between emulation types; now you can make your choice from a config menu during start-up. Your default choice is saved in EEPROM, so you only need to access the config menu if you want to choose a different emulation mode than you did last time. Unfortunately this combo firmware was born on the grave of the self-testing logic, which is now gone. That means I can’t use this to replace the regular production firmware. Maybe I’ll look into using JTAG boundary scan for a future firmware update, and re-implement the self-test using that method instead of with CPLD logic.
This firmware is a major change from version 0.4. The code for both floppy and HD20 emulation underwent significant changes, and the CPLD logic was altered substantially too. That means there’s an excellent chance I broke stuff. If you see any strange behavior during floppy or HD20 emulation that wasn’t present with the previous firmware, please let me know.
The scariest and most perplexing issue with this new firmware is that it doesn’t work on my original purple Floppy Emu board, the very first one I ever built back in April 2012. With this firmware, the purple board experiences constant SD card errors, or even spontaneously reboots during disk I/O! The behavior is similar to what I found on the first production boards, before I discovered that they needed more capacitance on the output of their voltage regulators. The purple board lacks that capacitor, and also has a few other small differences from the production boards. So I’d be prepared to believe the problems are all due to the purple board’s hardware, except that it worked fine with every previous firmware version, including Sunday’s version 0.4A-F66. So… yeah. There’s that.
I’ve tested this new firmware in both floppy and HD20 modes, on a Mac 512K, Plus, and IIsi, with one of the current batch of production boards as well as the first (hand-soldered) production board with serial #0001. No problems anywhere.
- Merged the firmware, with a menu-selectable HD20 or floppy mode. Default choice is stored in EEPROM.
- Changed the default HD20 disk icon to a standard Apple hard drive icon.
- LED now blinks during HD20 disk activity.
- Fixed a bunch of little bugs.
- Disabled self-tests.
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Combo Firmware 0.5A-F14
Notes on which Macintosh models you’ve confirmed to work with the latest firmware are always welcome.