DM15 old and new bugs
Posted: Wed Mar 14, 2018 8:38 pm
I recently went back to some personal studies on the hp15c system, and pulled out my old 2012 "DM15CC" to test a few ideas.
I updated it with the latest firmware (V16) available for this first generation machine (that was still in V8 up to now) and I was suprised to discover again an old bug related to the integrate function in the M80 version, that can corrupt memory. The bug is only present in the M80 version and was supposed to be fixed since a long time.
To reproduce the bug with the M80 version:
starting from an empty machine (Pr error),
key-in this small test program (to make integrate do something):
001 42,21,11 LBL A
002 43 11 X^2
003 43 32 RTN
then do:
4 ENTER 7 DIM A
2 ENTER 2 DIM B
MATRIX 1
RCL B ; this checks B[1,1]=0
0 ENTER 1 Integrate A
RCL B ; B[1,1] is corrupted !
This is the bug I reported to SwissMicros in 2012 and that was fixed in M80_V2 , see the firmware history !
I'm sure it was still fixed in M80_V8 (that I used a lot) and so should have appeared again later. I believe (but I didn't check on the actual machine) that it appeared again in V12.
Can someone confirm the bug is still present in the latest M80 versions (can't check on my early machine)?
Conclusion: don't use the M80 versions for serious work.
(you may ask why I've been using the M80 version rather than the full-power M1B version; well it was related to my own hp15c emulation activities of the time... now I switched my DM15 to the M1B version)
A second bug (minor):
This second bug is minor, but it seems it has not been reported yet. I checked in on versions V8 and V16.
If there is no program step and if all memory is allocated to user registers and matrices, then the MEM display shows 256 free registers instead of 0.
Starting with a M1B version:
MEM: 19 211 0-0
3 ENTER 33 DIM A
4 ENTER 28 DIM B
MEM: 19 256 0-0
J-F
I updated it with the latest firmware (V16) available for this first generation machine (that was still in V8 up to now) and I was suprised to discover again an old bug related to the integrate function in the M80 version, that can corrupt memory. The bug is only present in the M80 version and was supposed to be fixed since a long time.
To reproduce the bug with the M80 version:
starting from an empty machine (Pr error),
key-in this small test program (to make integrate do something):
001 42,21,11 LBL A
002 43 11 X^2
003 43 32 RTN
then do:
4 ENTER 7 DIM A
2 ENTER 2 DIM B
MATRIX 1
RCL B ; this checks B[1,1]=0
0 ENTER 1 Integrate A
RCL B ; B[1,1] is corrupted !
This is the bug I reported to SwissMicros in 2012 and that was fixed in M80_V2 , see the firmware history !
I'm sure it was still fixed in M80_V8 (that I used a lot) and so should have appeared again later. I believe (but I didn't check on the actual machine) that it appeared again in V12.
Can someone confirm the bug is still present in the latest M80 versions (can't check on my early machine)?
Conclusion: don't use the M80 versions for serious work.
(you may ask why I've been using the M80 version rather than the full-power M1B version; well it was related to my own hp15c emulation activities of the time... now I switched my DM15 to the M1B version)
A second bug (minor):
This second bug is minor, but it seems it has not been reported yet. I checked in on versions V8 and V16.
If there is no program step and if all memory is allocated to user registers and matrices, then the MEM display shows 256 free registers instead of 0.
Starting with a M1B version:
MEM: 19 211 0-0
3 ENTER 33 DIM A
4 ENTER 28 DIM B
MEM: 19 256 0-0
J-F