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The credit card size DM-15CC/DM-15 and the original size DM-15L are HP-15C clones offered by SwissMicros. They feature a miniUSB-RS232 command line interface for reading and writing data. Via this interface the HP-15C simulator can exchange data with these devices.

This documentation does not distinguish between the DM-15CC, the DM-15 and the DM-15L. They are all called DM-15.

If you order a DM-15 because of my simulator please mention that in your order at SwissMicros. For "How did you find us?" select "hp-15c-simulator@arcor.de".


Important note: Your DM-15 must have installed firmware version 9 or higher. Earlier version had issues with the command line interface and will not work!

An illustrated walkthrough of the setup procedure for Windows can be found here.

USB To Serial Driver Installation

Before the DM-15 interface can be used, a CP2102 USB to UART bridge driver must be installed on your computer. Drivers for various operating systems can be downloaded here. Recent Linux systems should come with the necessary cp210x kernel modules. The module may not be actived or loaded by default. See the modprobe and lsusb man pages for more details.

Simulator DM-15 Support

To enable the DM-15 support on the simulator open the Preferences dialogue box and activate "DM-15 Support" on the "DM-15" tab. With enabled DM-15 support If the DM-15 support is disabled, the sub-menu and the menu entries are hidden.

Serial Port Configuration

Start the DM-15 with CON (Press and hold C, then press and release ON). The display will read "SERIAL CONSOLE". Connect the DM-15 to your computer and determine the "Serial Interface Port" number the USB connection is mapped to: Open the Preferences dialogue box on the simulator and on the "DM-15" tab select the corresponding port number from the "Serial Interface Port" pull-down menu. This setting is not necessary under Mac OS X.


There are three types of DM-15 firmwares. Each provides a different number of registers:

Start the DM-15 with EON. The firmware information is displayed as long as you hold the ON key. Select the "Number of registers" that complies with the firmware of your DM-15.

It is recommended to have the same number of registers on the HP-15C simulator and the DM-15. If the number of registers differs, it is likely that not all data can be exchanged between the two devices. The data transfer also depends on the allocation of memory. For more details on allocation of memory see "Appendix C Memory Allocation" in the HP-15C LE Owner's Handbook.

The setup is completed. You should now be able to exchange data between the DM-15 and the HP-15C simulator.

Verifying The Setup

To verify the connection start the DM-15 into the serial console and connect it to your computers. On the simulator open the ON pop-up menu and select "DM-15 ▶ Read" or use the shortcut Ctrl. A dialogue window titled "DM-15 read" opens. Ensure that a least one of the four options is checked and click "OK". You should get a message "Data read successfully.". If you get another message, see the Messages section below.

◀ Setup ▲ Top


The following sections assume that you have set up the DM-15 support in the HP-15C simulator successfully. The option "Ask for each operation" should be off.

Writing And Reading A DM-15 Program

At first, load a program, e.g. one of the examples that came with the simulator, into the simulator. Then start the DM-15 into the serial interface and connect it to your computer. From the ON pop-up menu select "DM-15 ▶ Write" or use the shortcut Ctrl. In the dialogue window titled "DM-15 write" check "Program", uncheck the other options and click "OK". You should get a message "Data written successfully.".

Disconnect the DM-15 from your computer and then restart it or wait until the serial interfaces has timed out. Switch the DM-15 to Program mode and press SST several times to double check that the program has been transferred successfully to the DM-15.

To read a program from the DM-15 to the HP-15C simulator start the DM-15 into the serial interface and connect it to your computer. From the ON pop-up menu select "DM-15 ▶ Read". In the dialogue window titled "DM-15 read" check "Program", uncheck the other options and click "OK". You should get a message "Data read successfully.".

Reading and Writing Other Data

In the dialogue window that opens when you select to read or write you can choose which data will be exchanged between the DM-15 and the simulator. You can choose any combination of program memory, data storage registers, stack or flags. An area not selected for exchange remains unchanged on the target device.

The settings will be stored as default. If you do not want to be asked on every read or write operation, uncheck the option "Ask for each operation" under preferences.

Differing Configurations

The HP-15C simulator and the DM-15 can be configured independently. This applies to the number of available registers, the allocation of memory and all states like Complex mode, trigonometric modes etc. The allocation of memory on the target device is never changed automatically, even if not all data can be transferred. This leads to the following behaviour:

◀ Usage ▲ Top


◀ Messages ▲ Top

Preferences ▶