Brother Super PowerNote PN-8500MDSe vintage word processor

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In my recent eBay adventure I purchased a Brother Super PowerNote PN-8500MDSe vintage word processor from a local seller. The machine is powered by a Z80 processor and supports basic word processing, spreadsheet data entries as well as going online (perhaps not in the modern context of the Internet, but by using an old bulletin board system) through an optional dialup modem.

The machine is still in good condition – the front, back and side connector panels seem to have suffered from very little physical damage:

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It also comes with a 9V DC adapter, which is of the negative tip variant (not the more common positive tip type) and runs off 110V AC. I also bought a mini 220V-110V power transformer and permanently attached a note to the adapter using sticky tapes to avoid confusion (and possible magic smokes!):

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The machine boots up perfectly fine, greeting me with “Good Evening!” – which is the correct time of the day! Does the RTC battery still work after all these years? We’ll come to that in a while, but here is the photo of the greeting screen:

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After a few seconds the main menu will now show up:

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The following applications are bundled with the machine:

  1. Word Processor
  2. Spreadsheet
  3. Address Book
  4. Line by Line – a type of printing application which prints each line as you type
  5. Communication – a terminal application
  6. Calculator
  7. Scheduler / Calendar
  8. To Do List
  9. Clock
  10. File Management – to explore files on the floppy disk
  11. Disk Application
  12. Set Up

The first thing that I check is the Clock application. Amazingly it still showed the correct time as the CR2032 battery is still working:

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Nevertheless I decided to replace the battery as it is quite straightforward without having to disassemble the machine – a small plastic panel at the bottom of the word processor provides direct access to this battery. The machine also has slot for the main battery, which was an option module to be purchased separately, and unfortunately mine came with no main battery:

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This is the word processor application. Notice how the ruler provides the default left margin, making the document ready to be printed at any time:

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To quit most applications, press the CANCEL button at the bottom row of the keyboard. If that doesn’t work, hold down the CODE key and press the MENU/FILE button, and you will be prompted to save any pending changes before quitting.

This is the calculator application, supporting only basic mathematical operations:

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The address book application:

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This is the spreadsheet application. On startup, if the Brother floppy disk is inserted, it will prompt you to select a template to be used from the floppy disk; otherwise it will just create an empty file:

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The numbers in brackets are the sizes of the spreadsheets. The figure at the top shows how much free space is available on the machine, in this case a mere 240.6KB. This is how the checkbook spreadsheet (CHECKS.SPR, 9.7KB) looks like:

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Interestingly, from the main menu, there is an option called “Disk Management” allowing users to launch Brother-specific applications on the bundled floppy disks. Only two games are provided on the floppy disk that came with my machine, Tetris and Turnabout (a Reversi clone):

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There is nothing particular about this floppy disk – it is just a normal 1.44MB high density disk without any floppy copy protection mechanism commonly used at the time. It can be cloned using any modern disk copy program such as RaWrite or even MS-DOS DISKCOPY command. You can download an image of the disk here. The disk contains the following files and has 240,640 bytes free:

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This is the list of the files on the disk:

  1. *.WPT: word processor templates
  2. *.SPT: spreadsheet templates
  3. *.APL: applications (tetris and turnabout games)
  4. BROTHER.001, SCONV. EXE, CONVERT.EXE, INSTALL.BAT, *.OVR and *.OVL – Brother document conversion utilities, see details at the end of this article

With the floppy disk inserted, you can select between Tetris and Turnabout game in Disk Management:

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This is the Tetris copyright screen and the main game:

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This is the Turnabout game:

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Last but not least is the Set Up application, It allows user to change, among other things, the system password (which is not set by default) and printer configuration:

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Common printers (at the time) such as Brother, HP, Canon, Epson and IBM are supported. If “Other” is selected, it allows you to set custom printer configuration such as print quality and interface type (serial or parallel port):

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Only transmission speeds up to 9600bps are supported if a serial printer is selected. Most likely only text output will be supported in the custom printer configuration. I am not sure where to find working serial printers, or even working parallel port printers supported by this machine, in this day and age of USB and wireless printers.

The last thing to explore is the Brother conversion utility pack found on the floppy disk. It contains the following executables:

  • SCONV.EXE: spreadsheet conversion utility
  • CONVERT.EXE: word processor conversion utility
  • INSTALL.BAT: batch installer utility

The batch installer utility will simply create a folder name BROTHER on the C: drive and copy all files except SCONV.EXE to that folder. Here is the screenshot of the installer running on DOSBox:

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Running CONVERT.EXE after the installation and you will be greeted with a fancy-looking user interface with many options for document conversions from PC to the Brother word processor and vice versa:

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SCONV.EXE, on the other hand, is just a simple command-line spreadsheet conversion utility with some simple options for file format selection:

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Interestingly, although it says “Press Ctrl-C to quit”, during my experiment, Ctrl-C does not work and will simply print the heart symbol (ASCII code 3 for ETX, which represents the end-of-text character generated by Ctrl-C). This may have been a bug, or something that was overlooked during the development of this tool. Anyway, not that I am going to use the conversion tool with Lotus 1-2-3 any time soon, so it is not a problem for me.

My next challenge would be to install a custom OS on this machine, for example CP/M. I have read somewhere that it is possible since the processor is a Z80 that can run CP/M. I am still in the process of finding out more information on this. If you have any ideas, feel free to leave a suggestion here and I will be happy to try it out. :)

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ToughDev

ToughDev

A tough developer who likes to work on just about anything, from software development to electronics, and share his knowledge with the rest of the world.

4 thoughts on “Brother Super PowerNote PN-8500MDSe vintage word processor

  • August 26, 2018 at 12:27 am
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    Hey! I realize this is a few years old but I just happened across it. I have several PowerNotes (various models) and use one as my primary writing machine. They’re great for distraction-free work. My main one – the one that’s hooked up on my desk, with connection to a printer and a serial connection straight to my Windows/Linux dual-boot machine – is the same one I got new for Christmas in (I think) 98 or 99. I used it exclusively one semester in college when my 486 died and I didn’t have the funds to replace or repair it. It got me through! Anyhow, as this is an older post I was curious if you’d done anything else with yours. I don’t suspect you would have had much luck getting CP/M on it since in my experience the machines are pretty seriously locked down. What I would love to figure out is the process involved to compile those *.apl files (Tetris and Turnabout). I don’t think Brother ever released an SDK for these machines and in-house support never moved beyond those two games. It’s frustrating since it’s clear they *can* do more, but there’s no easy way for even a power user to make that happen. I’ve hoped for years that somebody more knowledgeable than me might attempt to reverse-engineer the apl format, but it hasn’t happened yet. I’ve managed to make mine ‘seem’ to do more by using the COMM program as a dumb terminal to my Linux laptop. For the most part if there’s something that will run at the command line in Linux in a text-only environment, these machines can handle the display. It’s fun (if not practical) to use Lynx for instance to look up stuff on the web while I’m writing. I occasionally use Pine to check my email with it. Anyhow, nice blog and like I said, just wanted to ask about an update.

  • ToughDev
    August 27, 2018 at 11:35 am
    Permalink

    Hi Roger,

    Thanks a lot for your comment. Great to hear that you’re still finding good use for the PowerNote nowadays! Yes, the built in terminal app is very useful to telnet to a modern Linux terminal and allows you to do a lot of things that would not have been possible on an original PowerNote. I also love black and white displays – they’re great for you to just focus on work without any distractions such as Internet, Facebook or youtube.

    I bought the device in early 2016 and the article was written around June that year. After writing the article, I studied the APL file format in details and did come up with some useful information. I summarized them below for the benefits of those who might be interested.

    There is nothing special about the APL file format. It just contains compiled Z80 instructions (64180 to be exact) with some header bytes added by Brother to identify the file. The file begins with a sequence of hex bytes 85C1010200004252 where 85 is likely from 8500 (the model number) and 4252 is ASCII codes for BR (short for Brother). Application code starts at 0x0008 with a jump or a call to the application entry point (8a6ah for TETRIS, 8d14h for TURN-ABT). I am not sure how the entry points are defined in the APL.

    Using dZ80 disassembler on the APL files, I was able to identify the main method for each of the APL, which starts immediately after 0x0008 in the APL file. This method contains a lot of CALL/JUMP instructions to invoke other assembly procedures, followed by conditional jumps such as JR to check for the return value. The identified assembly procedures also contain matching PUSH/POP statements and end with RET, which means that the disassembled assembly code is making sense.

    The data segments are stored towards the end of the file. For TETRIS, it starts at around 0x256c with the definition of the various Tetris shapes, followed by recognizable text (TETRIS, COL, KB, 1987, etc.). For TURN-ABT, this segment starts at 0x0eee with the game title string definition (TURNABOUT GAME). Although dZ80 disassembler does not recognize the data segment, I was able to make sense of it by looking at the raw binary data and analyzing the disassembled code. The data segment usually appears as a bunch of instructions that do not seem to do anything after the end of the various useful assembly procedures, identified by POP, RET statements or similar.

    Part of the architecture of the PowerNotes can also be deduced by looking at the disassembly. For example, OUT/IN instructions for addresses 0b8h, 0b0h, 0f0h, 16h and 70-75h can be found in various places. This could be for writing to the screen or reading keyboard input. I did not have time to figure this out, but perhaps it’s possible to understand them in more details with the help of IDA Disassembler.

    In the end using this knowledge, I was able to create an APL file that cleared the screen and printed “Hello World” when executed. And that’s about the extent of what my APL was able to do! As for running CP/M on this machine, I tried to open the machine up and although I was able to dump the ROM and identify some text strings, finding the correct format for the ROM file and replacing it with CP/M sounded like a tall order to me, so I didn’t proceed further. The PowerNote ROM size of 64KB will also mean that your compiled CP/M will need to be pretty small for it to fit.

    Another more feasible way is to create a floppy disk that contains an APL which works as a bootstrapper. When executed, this APL file would clear the screen, and attempt to boot CP/M OS stored on the same disk. A challenge with this is that Brother only accepts APL files stored on 1.44MB DOS FAT12 floppy disk, which might not be readable by many old variants of CP/M. Or maybe we’ll need 2 floppy disks, a 1.44MB disk just for the CP/M APL bootstrapper, and another in a CP/M compatible format which contains CP/M itself. Maybe someone with enough time can try this method.

    As for the fate of the unit, I sold it to a Z80 hobbyist at the end of 2016 in an attempt to scale down my vintage computer collection. So at the moment I am not able to experiment any of the above idea further. If you can try them on your PowerNote, let me know. I’d love to see CP/M running on this machine!

  • September 5, 2018 at 11:58 pm
    Permalink

    Well, you’re certainly much farther along than I ever made it! I like your proof-of-concept ‘Hello world’ APL. Unfortunately I don’t think the PowerNote series ever developed enough of a user base to encourage many others to attempt such projects. Hopefully someone (much better-versed in assembly than me) will come across this post and your comment and take up the cause. :-) I’d be happy if there was just a way to bootstrap BASIC into it with the capability to read and write to the disk drive.

  • ToughDev
    September 6, 2018 at 10:12 pm
    Permalink

    Yes, regrettably the PowerNote never became as popular as some other similar products of that era such as the Commodore 64. With regards to the bootstrapping BASIC idea, I guess it’s possible to modify existing BASIC for Z80 source code to support the PowerNote architecture. For simple tests, just supporting reading from keyboard or writing to screen should suffice. Hope someone with enough time can explore this further …

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