HP-15C: DM15

Version 4.5.00, Build 6308
© 2023 Torsten Manz
H E W L E T T · P A C K A R D 15C
A Simulator for Windows, Linux and macOS

# DM15

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 collectively referred to as DM15.

## Simulator Support

### Menus

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

- the ON popup menu has an additional submenu "DM15"
- the "File" menu in the main menu bar has three additional entries

Menu item | Shortcut | Description
--- | --- | ---
Read DM15 | Ctrl–↑ | Read data from the DM15 to the Simulator.
Write DM15 | Ctrl–↓ | Write data from the Simulator to the DM15.
System Info DM15 | Ctrl–I | Read the system information from the DM15.

When the DM15 support is disabled, the submenu and the menu entries are hidden.

### DM15 Firmwares

There are three versions of the DM15 firmware. Each of them provides a different number of registers:

- DM15: 64 registers; like the original HP-15C
- DM15_M80: 128 registers
- DM15_M1B: 229 registers

Start the DM15 with E–ON. 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.

◀ Simulator Support ▲ Top

## Serial Port

The complete description of the DM15 Serial Console and the driver installation can be found in SwissMicros' Voyager Series User Manual.

Important note: You must install firmware version 9 or higher on your DM15. Earlier versions had issues with the command line interface and will not work.

### USB To Serial Driver Installation

To recognise the DM15 interface, a "CP2102 USB to UART bridge driver" must be available on your computer.

- Windows:
  Download and install the Windows driver from the Silicon Labs drivers page.

- Linux
  Recent Linux systems should come with the necessary cp210x kernel modules. The module might not be activated or loaded by default. Please see the modprobe and lsusb man pages for more details.

- macOS
  For macOS Catalina and older versions, download and install the driver from the Silicon Labs drivers page.

  Since macOS Big Sur a suitable driver is already built into the system. If you experience timeout issues with this driver, use the Silicon Labs.

### Serial Port Configuration

Start the DM15 with C–ON (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:

- Windows:
  Open the Windows Device Manager. In "Ports (COM & LPT)" find the entry "Silicon Labs CP210x USB to UART Bridge (COM`##`)" and note the COM port number.

- Linux
  Look for a device /dev/ttyUSB*. By default, and if no other serial interface is connected, the port number should be 0.

  Make sure that you are a member of the same UNIX group, usually dialout, as the tty device. Otherwise you might not be able to read from or write to the device.

- macOS
  The Silicon Labs driver creates a device /dev/cu.SLAB_USBtoUART that does not take a port number.

  The devices of the built in driver have the form /dev/tty.usbserial-####.

Open the Preferences dialogue on the Simulator. On the "DM15" tab select the corresponding port number from the "Serial Interface Port" pull-down menu. This is not required for the macOS Silicon Labs driver.

### 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 popup menu and select "DM15 ▶ Read" or use the shortcut Ctrl–↑. A dialogue box titled "DM15 read" opens. Ensure that a least one of the 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.

### System Information

The menu entry "System Info DM15" opens a new windows providing the following information about the DM15:

- Firmware and version

  The firmware type, with the number of total registers, and the firmware version.

- Date and time

  The date and time on the DM15 in the format "YYYY-MM-DD HH:MM:SS" and the time difference, in seconds, to your computer.

  The "Synchronise" button synchronises the DM15 clock with the computer clock. Computer clocks are (normally) connected to an NTP server on the Internet and are more accurate compared to the DM15 internal clock.

  The computer's date and time is written to the DM15 and then date and time are read again from the DM15 for validation. This can result in a time difference of 1 second, which can be ignored.

- Battery voltage and remaining power

  The current battery voltage and the estimated remaining power.

  The measurement of the voltage influences the measurement itself. Directly consecutive measurements can deliver different voltages. The discharge characteristics are also different for batteries from different vendors. The remaining power is therefore only an estimate.

  This information is not available on the first batch of the credit card sized DM-15CC's.

◀ Serial Port ▲ Top

## Usage

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 popup 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 verify 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 popup 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 shall be exchanged between the DM15 and the Simulator. You can select any combination of program memory, data storage registers, matrices, 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:

- Program

  A program is transferred if the target device configuration provides at least as many registers in the common pool as the program allocates. For example, let's take the following combination: An HP-15C Simulator with 46 program registers and a DM15 with the 128 register firmware and the standard layout with 110 program registers. All programs from the Simulator can be written to the DM15, but not the other way round.

  Increasing the number of data storage registers on the DM15 to 100, key sequence 1 0 0 f DIM (i), reduces the number of registers in the common pool to 29. Now only simulator programs allocating up to 29 registers can be written to the DM15. Although the total number of registers on the DM15 (128) is higher than that on the Simulator (64).

- Data Storage

  The data storage registers are transferred only if the target device has at least as many data storage registers as the source device. Otherwise, the error "Too many storage registers for current memory configuration." will occur. If you see this message, check the memory configuration on both devices with g MEM.

  Example: The Simulator shows 19.110 0-0 and the DM15 shows 30. 99 0-0. The 19 storage registers on the Simulator can be transfered to the first 19 of the 30 registers on the DM15 without a problem. If you try to transfer data in the opposite direction, not all 30 register can be transfered and the message is shown.

  Additional data storage registers on the target device remain unchanged.

- Stack

  The real stack can always be transferred. The complex stack can be transferred only if both the source and the target device are in Complex mode. No warning or error message is shown, if the complex stack is not transferred.

- Flags

  Only the flags 0 through 7 can be transferred. Flag 8, Complex mode, and flag 9, display blinking, are never transferred.

◀ Usage ▲ Top

## Messages

- Error when connecting via serial port #

  This error occurs if no device is connected to the serial port interface configured under 'Preferences'.

- Connection timed out

  After some time of inactivity (~ 60 seconds) the command line interface on the DM15 times out and switches to Run mode. Restart the DM15 with C–ON to reactivate the command line interface.

- Error while writing [reading]

  An error occured while writing [reading] the DM15 memory.
  Please ensure that you have installed firmware version 9 or higher on your DM15. If the problem persists, please contact me.

- Memory not initialised

  The DM15 memory was not loaded completely.

- Firmware requires ## register mode. See Preferences dialogue

  The DM15 firmware provides more registers than configured in the Simulator. Open the 'DM15' tab in the Preferences dialogue and select a suitable register size.

- Too many data storage registers for current memory configuration

  More data storage registers are configured on the source device than on the target device.

- Unknown code '##'.

  The program to be loaded contains an unknown key code.

- Program too large for current memory configuration

  A program allocates more registers than are available on the target device.

- '/dev/ttyUSB#' was not recognised as a serial device

  On some Linux systems '/dev/ttyUSB#' might not be recognized as a serial device.

◀ Messages ▲ Top

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