hp41cx named variables in extended memory

[Artur - Brasil]

Revison A (mars, 18th)

As promised, although nobody indeed made even any comment about it, here the routine to create named variables in X-memory, complementing the X-Memory numbered registers routine published before.

The vars must have a name up to 5 chars. Example: WIDTH. Please, do not use : in variable name.

All variables will be saved in a X-files which names you give. Each X-File has no limit for number of variables, only limited to memory available.

The use is very simple: put the name of file (to be created or already existing) in ALPHA, by example: BOX. If file does not exist yet, it will be created; if already exists, the program just open it.

IMPORTANT: both routines (STA and RCA) make the x-file the current one only at initialization (XVARN). So, if your programs make use of others X-files, you will need to make the X-Reg file the current one again.

Call XVARN (X-Variables Named) routine:

ALPHA BOX ALPHA
XEQ ALPHA XVARN ALPHA

Now, you must have one text X-File named BOX. (See cathalog 4 in CX)

For creating and saving the variable LEN with value 10, just type:
ALPHA LEN ALPHA 10 XEQ ALPHA STA ALPHA. (Store Alpha named variable)

Create as many variables your X-Memory modules can hold.
Not allowed two variables in the same file with same name.

For recovering the contents of any named variable, put its name in ALPHA register and call RCA routine.

ALPHA LEN ALPHA XEQ ALPHA RCA ALPHA --> X: 10

I saved variables in X-file as: namen.nnnnnnnnEsnn (s - signal)
Numeric values are stored in American and Scientiic format, up to 9 digits of precision.
This may lead to something like: LEN:1,200000000E1 which is a waste of precious bytes on 00000000 sequence.
So, I created a routine to clean these unneccessary zeroes and compress the file to minimal registers needed.
Eventually, call CLNVAR (clear nominal var file), with the current x-file as the one you want to clean or insert a call to it in the XVARN routine. So, it will run when you start the process (remove the VIEW commands in routine CLNVAR.

Here is the full code (REV A)

1 LBL "XVARN"
2 X<> L
3 RDN
4 1
5 SF 25
6 CRFLAS
7 CF 25
8 X<> L
9 RTN

10 LBL "STA"
11 X<> L
12 RDN
13 58
14 XTOA
15 RDN
16 POSFL
17 X<0?
18 GTO 02
19 DELREC
20 X<> L
21 LBL 03
22 RCLFLAG
23 RDN
24 SF 28
25 SCI 9
26 ARCL X
27 APPREC
28 RUP
29 STOFLAG
30 CLX
31 SEEKPT
32 RDN
33 RTN

34 LBL 02
35 X<> L
36 ASTO L
37 CLA
38 FLSIZE
39 ARCL L
40 x<> L
41 RDN
42 4
43 ST+ L
44 X<> L
45 RESZFL
46 RDN
47 GTO 03

48 LBL "RCA"
49 STO L
50 CLX
51 SEEKPT
52 RDN
53 58
54 XTOA
55 RDN
56 POSFL
57 X<0?
58 GTO 01
59 GETREC
60 CLX
61 SEEKPT
62 RDN
63 RCLFLAG
64 X<> L
65 SF 28
66 SCI 9
67 ANUM
68 X<> L
69 STOFLAG
70 X<> L
71 RTN

72 LBL 01
73 X<> L
74 "^NOT FOUND"
75 AVIEW
76 BEEP
77 RTN

78 LBL "CLNVAR" compress named vars x-file to minimal neccessary of bytes
79 CLA
80 X<> L
81 RDN
82 FLSIZE
83 VIEW X
84 LBL 06
85 CLX
86 SEEKPT
87 "0E"
88 RDN
89 POSFL
90 X<0?
91 GTO 07
92 VIEW X
93 ST/ X
94 DELCHR
95 GTO 06
96 LBL 07
97 RDN
98 CLA
99 FLSIZE
100 SF 25
101 LBL 08
102 VIEW X
103 DSE X
104 RESZFL
105 FS? 25
106 GTO 08
107 CLX
108 SEEKPT
109 x<> L
110 BEEP
111 END

Hope it can help someone!

Best wishes from Brazil
Artur