ervin@pinbot.enet.dec.com (Joseph James Ervin) (02/19/91)
Alonzo Gariepy writes, in his notes on the HP48SX: >Here is a list of interesting >locations (the initial 7 is mapped to an F in scan mode): > >Real Address Description > >#704EAh key buffer >#70579h top (end) of stack >#7057Eh bottom (start) of stack >#70583h ?? local variables ?? >#70588h ?? internal loop ?? >#7058Dh ?? menu keys ?? >#70592h HOME directory >#70597h end of HOME directory (7FFFB) > (points to five 0 nibbles, probably used for ATTACH) I have been trying to get a grip on the internals of the 48SX so that I can do some machine language programming, but I'm having a bit of trouble. I have a 128KB memory module installed in port 1, and some of the addresses that Alonzo points out in the aforementioned memo don't seem to work the same on my machine. Is it necessary that I remove the memory module (which is merged memory, by the way) in order to get the addresses to work right? For example, if using the memory scanner I check where the end of the stack is supposed to be, I get an address around AC3B9 or thereabouts. If I go there in the memory scanner, I don't see what I expect to see. In other words, if I put something on the stack, I can't seem to find it in memory using the memory scanner. Is there some aliasing magic going on which prevents me from seeing the memory contained in the merged memory module? Any insight would be very much appreciated. >>>Joe - "who is still bewildered at how the information in the internals lists was obtained".