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Firmware V29 for DM1x/DM41(L) units

Posted: Wed Jun 05, 2019 10:05 am
by grsbanks
Firmware V29 has been released for DM1x and DM41 units.

There's something for the DM41 and for extended DM15 variants in this update.


There was a bug in the keyboard handling in V27 that prevented the user from acknowledging alarms if they became due and woke the calculator up after it had powered down automatically. This was fixed in V28 but unfortunately it led to another bug that is now fixed in V29.

On the original HP-41CX (or 41C/CV with the Time Module), if there is an unacknowledged alarm in CAT 5, it sounds again when the user powers the calculator off, thus serving as a reminder. If the calculator powers off automatically before the alarm is acknowledged then it powers off silently, with no reminder. Unfortunately, a DM41 running V28 will sound the alarm again when the calculator powers down automatically.

V29 corrects this and restores the expected behaviour.

DM15_M80 / DM15_M1B

The HP-15C and therefore the DM15 family of machines allow a program to jump to a given program line by storing the negative of the line number in the index register and executing GTO I.

Restrictions in the original ROM didn't allow jumping to a line number greater than 448. The original HP-15C couldn't hold more than 448 lines, so it didn't matter. The DM15_M80 can hold up to 896 lines and the DM15_M1B up to 1603, so the ROM has been patched to allow any 3-digit number. This covers the entire program space of the M80 variant.


The initial storage register allocation after a reset has been brought in line with the HP-15C and the other DM15 variants. The DM15_M80 now starts off with 20 storage registers (like everyone else) and 110 program registers:

DM15/HP-15C: 19 46 0-0
DM15_M80: 19 110 0-0 (was 30 99 0-0)
DM15_M1B: 19 211 0-0

Firmware files Instructions can be found here:

Remember, folks, that a firmware update on a DM1x results in "Pr Error" on the display. This does not indicate a failure, it is normal behaviour!

SHA1 checksums:

Code: Select all

5a6435c179e3213a362aae8cad4d408fbeff0f48 DM10_29.hex
281b2ec19d7226e254ea71f2f8906166eb4e1529 DM11_29.hex
b82b848b4dc6ca0765730417c84a96f221d23ca2 DM12_29.hex
082f0598906aa96ffa9dd4c5cc3762e9afec597a DM15_29.hex
2c130671476978b4ae3d18d5d2995130595d3b89 DM15_M1B_29.hex
2447ba5a090625bc6e463bca47838410a2916a62 DM15_M80_29.hex
c6b3a359cf29a254669fe95842bef87a11d8f13f DM16_29.hex
05b811d25981f6755799492143928a5632455fc5 DM41_29.hex

Re: Firmware V29 for DM1x/DM41(L) units

Posted: Wed Jun 05, 2019 1:59 pm
by rprosperi
Just updated my DM15L to v29, quick and easy, no glitches.

Thanks to the team!

Re: Firmware V29 for DM1x/DM41(L) units

Posted: Fri Jun 07, 2019 10:33 am
by michaelzinn
Pssst! Wanna jump to line numbers with GSB I but it's buggy? Try this instead 8-) :

Code: Select all


Re: Firmware V29 for DM1x/DM41(L) units

Posted: Fri Jun 07, 2019 3:40 pm
by grsbanks
"Doesn't do what you expect" != "buggy" :)

Re: Firmware V29 for DM1x/DM41(L) units

Posted: Wed Jul 17, 2019 5:32 am
by StatsDoctor
I really like the v29 firmware update for the DM 15L. Everything is running smoothly and efficiently!

Thanks to the team who put together this update. Also, thanks to the team for continuing to keep the firmware updated!


Re: Firmware V29 for DM1x/DM41(L) units

Posted: Mon Sep 09, 2019 12:26 pm
by Boub65
this a great improvement for DM15_M1B (better) program memory management!

Do you know if the capability to allocate more than 99 registers is in the radar or not ? I understand that it's a difficult task...