So I've been working away on some interface improvements which is part of the main push for this next version. However there is some more emulation related news to report.
I've talked a little bit about the Sega Master System and it's ability to take software through 4 separate "ports" or "areas". You have the cartridge slot, card slot, expansion slot and BIOS slot. The BIOS slot is unavailable however unless you get the soldering iron out, so that leaves 3 areas you can run software from. At least on the SMS1, the card and expansion slots were removed on the SMS2 leaving only the cartridge slot.
Most emulators care little for these slots, BIOS emulation was added maybe a decade ago by some emulators (I believe FreezeSMS or Emukon added it first) however the other slots have been pretty much unused. Now the card slot was the only slot commercially used so I will just talk about this one.
The card slot has different dimensions to the cartridge slot. It was designed to fit small, thin card like devices which had games on them. Sega's idea was that kids would bring the cards to school like baseball cards and swap them. The general thought when it comes to emulators is what is the point in emulating the card slot when it's the same as the cartridge slot. Well it isn't the SAME, at least exactly. The game can detect what slot it is running from, and in turn can do different things if it wanted to.
I don't think there has been much research to determine if there are many differences between games run from card slot and cartridge slot. There probably are no major ones. But starting with RetroCopy v0.800 the games which were released on card will have their own entry to be clicked on so you can get some accurate card slot action going. 
Also I have made the flags smaller and added the ability to see up to 5 of them at once now instead of only 3.