HP-41 Extended Memory data to card?

[Dieter]

(09-28-2016 06:14 PM)4ster Wrote:  I know the normal process would be to save a complete X-memory data file to a block of main memory and then write that block onto cards with the card reader. It seems to me that a program could be written that copies 16 registers at a time to main memory, to read or write a single card track, and then use the same 16 registers for the next chunk of the data file. This would save dedicating a large part of main memory solely to transfer a whole data file to cards.

Sure. But that's so trivial that I don't think you need a program for this.

Let's assume your data is stored in an X-Memory file named "DATA".

Code:

"DATA"  0 SEEKPTA  // make "DATA" current file, reset pointer

0,015 GETRX        // Read 16 values from X-Mem into main memory
WDTAX              // save these registers on card

0,015 GETRX        // Read next 16 values from X-Mem into main memory
WDTAX              // save these registers on card

...

The last round probably will cause an END OF FL error as there are no further 16 values left in the file that could be read. In this case get the last data this way:

Code:

FLSIZE RCLPT -     // number of remaining data in file
1 - 1000 /         // create control number 0,nnn
GETRX              // Read last data from X-Mem into main memory
WDTAX              // save last registers on card

Of course you can also write a short program that does this for you. Simply use a flag 25 test for the last chunk of data. And be sure that the last control number is greater than zero. ;-)

Edit: for instance this way...

Code:

01 LBL "XM2CRD"
02 AON
03 "FILE NAME?"
04 STOP
05 AOFF
06 0
07 SEEKPTA
08 LBL 01
09 SF 25
10 ,015
11 GETRX
12 FC?C 25
13 GTO 02
14 WDTAX
15 GTO 01
16 LBL 02
17 FLSIZE
18 RCLPT
19 -
20 1
21 -
22 1 E3
23 /
24 X<=0?
25 GTO 03
26 GETRX
27 WDTAX
28 LBL 03
29 "OK"
30 PROMPT

Beware: I have not tried this on a real 41 / X-Mem / card reader combo. Try it and see if it works for you.

Dieter