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The credit card sized DM-15CC/DM-15 and the DM15L in original size 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 DM15L. They are all called DM15.

If you order a DM15 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 DM15 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 DM15 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 might not be actived or loaded by default. Please see the modprobe and lsusb man pages for more details.

Simulator DM15 Support

To enable the DM15 support on the Simulator open the Preferences dialogue and activate "DM15 Support" on the "DM15" tab. While the DM15 support is activated, the following additional menu entries are available: If the DM15 support is disabled, the submenu and the menu entries are hidden.

Serial Port Configuration

Start the DM15 with CON (Press and hold C, then press and release ON). The display will read "SERIAL CONSOLE". Connect the DM15 to your computer and determine the "Serial Interface Port" number the USB connection is mapped to: Open the Preferences dialogue on the Simulator and on the "DM15" tab select the corresponding port number from the "Serial Interface Port" pull-down menu. This setting is not required under Mac OS X.


There are three types of DM15 firmwares. Each of them provides a different number of registers:

Start the DM15 with EON. The firmware information is displayed as long as you hold the ON key. On the Simulator select the "Number of registers" that complies with the firmware of your DM15.

It is recommended to have the same number of registers on the HP-15C Simulator and the DM15. 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 DM15 and the HP-15C Simulator.

Verifying The Setup

To verify the connection start the DM15 into the serial console and connect it to your computer. On the Simulator open the ON pop-up menu and select "DM15 ▶ Read" or use the shortcut Ctrl. A dialogue box titled "DM15 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 a different message, see the Messages section below.

◀ Setup ▲ Top


The following sections assume that you have successfully set up DM15 support in the HP-15C Simulator. The option "Ask for each operation" should be switched off.

First load a program, e.g. one of the examples that comes with the Simulator, into the Simulator. Then start the DM15 into the serial interface and connect it to your computer. From the ON pop-up menu select "DM15 ▶ Write" or use the shortcut Ctrl. In the dialogue box titled "DM15 write" check "Program", uncheck the other options and click "OK". You should get the message "Data written successfully.".

Disconnect the DM15 from your computer and restart it or wait until the serial interfaces times out. Switch the DM15 to Program mode and press SST several times to verfiy that the program has been successfully transferred to the DM15.

To read a program from the DM15 into the HP-15C Simulator start the DM15 into the serial interface and connect it to your computer. From the ON pop-up menu select "DM15 ▶ Read". In the dialogue box titled "DM15 read" check "Program", uncheck the other options and click "OK". You should get the message "Data read successfully.".

Reading and Writing Other Data

In the dialogue box that opens when you select to read or write you can choose which data is to be exchanged between the DM15 and the Simulator. You can select 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 are saved 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 DM15 can be configured independently. This applies to the number of available registers, the memory allocation and all states like Complex mode, trigonometric modes etc. The memory allocation 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 ▶