Old Hardware Emulated :Psion Model 3 Series of Handhelds via DOSBox

May 26, 2021

Time For Emulator on Emulator Action! (Wait a minute, that doesn't sound right)

Psion Series 3 Handheld Computer (Wikipedia)

Psion PLC

The Psion 3 Series of PDA's were a major leap forward in portable computing. These devices are usually considered the first true PDA's (Personal Digital Assistant). The PDA was essentially the precursor to the smartphones, which are a direct descendant from these devices. The Psion 3 devices existed even before the term was coined! There were various models within the Psion 3 Series. The first models, the Psion Series 3, were released in 1991 and continued with various models through most of that decade.

These devices were made by Psion PLC. Based in London, England, the company specialized in portable computing devices throughout the 80's starting with the Psion Organizer in 1984. These devices were very well-received in the marketplace and there success lead to the Organizer II handheld in 1986. Both of these devices, like the vast majority of portable computers in the 80's, were powered by 8-bit processor. As the 90's continued, 16-bit processors became more accessible. Miniaturized versions of these CPU's meant that even hand-held computers could start incorporating them now.

The Menu for the Psion Series 3. The emulator for the system is emulated under DOSBox.

System Specs

The Psion 3 series of organizers were powered by a 16-bit NEC V30 Processor running at 7.68MHz. The V30 was a enhanced version of the NEC V20 processor. This CPU already made a name for itself as the desktop versions of these processors were popular upgrades for owners of IBM PC/XT-Compatible systems that wanted a CPU faster than what Intel provided. The NEC V20 was compatible with the Intel 8088 while the NEC V30 was compatible with the Intel 8086 processor.

The Psion 3 had a innovative clam-shell design and slots for two memory cards which could be used for backup or for applications.

The first model, the Series 3, had a monochrome LCD display that was 240 by 80 pixels . The OS was supplied on the ROM chip that 128 KB or 256KB, depending on the model. Like most portable computers in there day, file transfer could to or from the device via RS-232 serial communications port. The Series 3 also had a built-in keyboard as well, which would become a trademark for these devices. The unit is powered by two AA batteries which provided between 20-35 hours of battery life (Wikipedia).

The Series 3 is powered by the EPOC SIBO operating system. EPOC SIBO is a 16-bit operating system written in 8086 assembly language. It's a single user, preemptive-multitasking OS. For a handheld devices, this was considered state-of-the-art at the time as preemptive multitasking meant that not only could multiple programs be opened at once, but those programs could be running in the background as well. Most operating systems designed for handhelds were usually very simple or the user interfaces were character-based, like BASIC. However SIBO applied the concepts of a WIMP(Windows, icons, menus, and pointer) desktop. There would be many revisions to this OS as the series continued. According to the Wikipedia article, SIBO was a code-name for either "single-board organiser" (British spelling) or "sixteen-bit organiser".

Even though these devices are usually considered the first PDA's, they are missing aspects that would be embraced by later devices, like the Palm Pilots. The display was not a touchscreen. The menus had to be navigated using the keys. Because there was no touchscreen, there was no stylus either, which would become another common feature for the Palm Pilot.

The only emulators I could find for these series of organizers ran under MS-DOS. These emulators were originally provided for software developers to write there own applications for the platform. I've built a DOSBox configuration that could run these systems. In short, I'm using a emulator to run a emulator. Setting this up requires knowledge of both MS-DOS and setting up a DOSBox configuration file. While it's not the easiest thing in the world, it's not the hardest either. Just place the emulators in a folder, and then redirect DOSBOX to look for them in that folder. This will be covered in greater detail when covering the Psion 3a/c PDA, especially when running it on Magic DOSBox for Android.

The original series came with a simple editor/word-processor, alarm, and the OPL (Organiser Programming Language). This programming language shared similarities to BASIC. It allowed developers to write there own simple programs for the device. The programs were very simple, but yet, very powerful and capable for those that used them.

On DOSBox, the Series 3 emulator uses a black background, compared to the gray background in the later series.

The Time/Alarm program

Psion 3 Classic System emulated under DOSBox. The text editor is running.

The OPL programming language

Final Thoughts

These devices created the concept of the PDA. A small, handheld device that was specifically geared towards keeping contacts, important information, appointments and a organized schedule at your fingertips using a digital medium. The emphasis on having your contacts close to you would play a major role when smartphones would come along and allow you to connect to them via social media. The concept of the PDA, and thus the modern smartphone and tablet, have been solidified with these handheld computers. This is the first in a series of articles examining the Psion Series 3 models of organizers.

Everything has to start somewhere, right!

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