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From: n233dk@tamunix (Frederick Grevelle)
Newsgroups: comp.sys.handhelds
Subject: Improved syseval peek (28s)
Message-ID: <5209@helios.TAMU.EDU>
Date: 4 May 90 06:56:00 GMT
Sender: usenet@helios.TAMU.EDU
Organization: Texas A&M University
Lines: 21

Here is an improved version of the SYSEVAL PEEK routine for the HP28s.
There is no address of which I am aware that will result in a memory
failure when peeked. Some addresses will still return false results.
This can be delt with by adding or subtracting 1 from the address
being peeked and comparing results. This is nearly as fast as the
best of the user written versions available; Alonzo Gariepy's PIG.
I also recommened the use of some sort of keyword command to check
that the stack argument is a binary integer. (i.e. B->R  R->B)

     PEEK

<<  10  -                 : 10 nibble truncation adjustment
    # 43ADh  SYSEVAL      : binary->short integer
    # 3A64h  SYSEVAL      : get 5 nibbles past 02911
    # 0h                  : slot result object
    # 39103h SYSEVAL  >>  : add contents of level 2 address to # 0h

                          
                                       Happy hacking- 

                                       Rick Grevelle