Tandata TD1100 dialer

It took me a lot of work to discover this information, and I am not sure why it's so cryptic. But anyway... Some time ago I mentioned I had a Tandata TD1100 viewdata set on the bench. At power-on you get a dialing menu, the numbers for which are clearly stored in the battery-backed RAM. Dialing a number from the menu was easy (<menu number>#, for example 2#). But I could not find out how to stroe numbers in the menu, everything I tried got 'Please Try Again'. I am not suprised I didn't find the right sequesnce by trial and error. It is clearly designed to be impossible to get by accident. I fianlly found it by readign otu the firmware ROM (it is socketed, but I can assure you that desolderign a 24 pin DIL chip would have been trivial compared to the rest of it), writing a quick-and-dirty disassmbler for 6502 code (soemthing that took me most of yesterday (Newtonsday) afternoon [1]), and then going through the lisitng. [1] This would ahev been a lot easier if the 6502 data sheet I'd been workign from handn't been written by a boatie. There's a nice 16*16 table of the nmemonics, the rows and columns being numbered from 0-F. It turns out that the _rows_ are the most significant nybble, in other words you read it across, not down. The lables indicating this are in tiny type in one corner, and I missed them. So I had to move my table of mnemonics aroudn a bit. ARGH! My first guess, which turned out to be correct, is that it would use CMP instructions to identify wheter a typed character was 'acceptable' or not. So I searched the listing for these, and found a sequence of CMPs which seemed to do the right thing. I then spent some time figuring out what that routine does, and I finally got the sequence to load a number into the dialer menu. It is : Turn on 'program mode' with the switch on the back first and type : <menu position>*****<Number to dial># For exxaple 2*****123456# will store 123456 into the second position of the menu. Note that it's 5 '*'s. No fewer (or you get an error), no more (or you get spaces at the start of the number in the menu. If you do not turn on program mode, the entry is ignroed -- no error message. -tony