Table of Contents

Purchase Information
Firmware
RTC
- Update January 2026
Swiss Micros Info
HP-41CX Owner's Manuals
Further Information

←Calculator Hardware/Firmware

DM41L Info

Purchase Information

Date : 26 Aug 2024
From : Swiss Micros (Direct)
Price : approx £200
Serial : 05121
Battery Change : 26/08/24

Firmware

cp210x_universal_windows_driver.zip

Date	Serial No.	Firmware	Version	Firmware Files	Firmware Tool
26/08/24	05121	DM41	V32	dm41_32.zip	voyage_firmware_tool.zip
01/02/25	05121	DM41	V33	dm41_33.zip
21/12/25	05121	DM41	V34	dm41_34.zip	Linux, using lpc21isp

RTC

RTC is not capable of calibration/correction?
- Perhaps the HP41CX Time corr. feature works?
- Gather data on inherent time error for a period and then try to change the values via HP41CX functionality

Update January 2026

Using my python Watchcheck

Date Start	Date Check	Delta	Latest Rate Error	Average Rate Error	Comments
23/01/26		+49.6			New Period Start
23/01/26	24/01/26	+50.6	+1.0	+1.0	After 24 hours
23/01/26	26/01/26	+52.8	+1.2	+1.1	After 3 days
23/01/26	27/01/26	+53.6	+1.0	+1.1	After 4 days

Swiss Micros Info

Firmware : https://technical.swissmicros.com/voyager/firmware/
Documentation : Online HTML User Manual
Documentation : PDF Manual
Product Page : DM41L

HP-41CX Owner's Manuals

Download from https://literature.hpcalc.org

HP-41CX Owner's Manual Vol. 1 : https://literature.hpcalc.org/community/hp41cx-om-vol1-en.pdf
HP-41CX Owner's Manual Vol. 2 : https://literature.hpcalc.org/community/hp41cx-om-vol2-en.pdf
HP-41CX Quick Reference Guide : https://literature.hpcalc.org/community/hp41cx-qrg-en.pdf

Further Information

calculator, dm41l