68HC11A0 - Terminal Emulator - Page 1
Forum section: electronics / general

author: jbd_68HC11A0
author_rank: Newbie
timestamp: January 02, 2025, 04:56:10 pm
content: I have an AES (Advanced Educational Systems) V.1.2 (1998) board with an 68HC11A0 with on board 32k ROM, 32k RAM and RS-232 interface. I have AS11 cross assembler software that works (under DosBox-X) and am looking for a Terminal Emulator that can run in Windows 11 or under DosBox-X. I am interested in uploading .S19 assembly files to the on board RAM. Currently, I have a terminal emulator that allows me to use the onboard Debugger to program the contents of the .S19 files into RAM byte by byte (extremely slow and requires re-entering/typing if power to the system board is lost). The Debugger allows for program execution. Any help would be appreciated.

author: audiotubes
author_rank: Regular Contributor
timestamp: January 02, 2025, 06:11:49 pm
content: Would something like Teraterm work for you?

author: jbd_68HC11A0
author_rank: Newbie
timestamp: January 02, 2025, 07:19:17 pm
content: I am currently using a terminal emulator from Load Tec. I have tried PuTTY, Kitty, and TeraTerm emulators without success.Thanks.

author: shabaz
author_rank: Frequent Contributor
timestamp: January 02, 2025, 07:47:54 pm
content: There's a NXP/Freescale/Motorola app note doc with example BASIC-language code to read a .s19 file and parse it and send the values over a serial connection. It would be easy to convert that to Python, and then you could just run the Python code, passing your .s19 filename as a parameter, and the serial port number.If you're unfamiliar with Python, try one of the AI help systems, it's a fairly simple task and they should be able to handle it reasonably well, with only minor debugging required hopefully.

author: bobxyz
author_rank: Contributor
timestamp: January 02, 2025, 09:14:57 pm
content: Originally, Motorola offered a DOS-based debugger for the 68HC11 called PCBUG11:https://www.nxp.com/docs/en/user-guide/M68PCBUG11.pdfBeing DOS based, and programmed to go direct to the COM ports on a PC/XT or PC/AT, it didn't do well as processor speeds increased, and DOS was replaced by Windows. Using DOSbox helped sometimes:http://support.technologicalarts.ca/docs/PCBug11/PCBug11withDOSbox.txtFor a while, there was a replacement called JBUG11:https://www.cs.uml.edu/~fredm/handyboard.com/oldhb/software/util.htmlAnd there's a French replacement called WinBug11:http://alain.birtel.free.fr/(translated:https://alain-birtel-free-fr.translate.goog/?_x_tr_sch=http&_x_tr_sl=fr&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=sc)The ^^^ WinBug11 Beta version, from 2002, supports WindowsXP, and might? still be usable in Win11.

author: brucehoult
author_rank: Super Contributor
timestamp: January 02, 2025, 09:57:37 pm
content: Quote from: jbd_68HC11A0 on January 02, 2025, 07:19:17 pmI haven't heard of Kitty, but millions of people use the other two. I've been using PuTTY for I suppose 30 years. It works fine with physical COM ports (you said your board has actual RS232), as well as virtual ones such as USB Serial, or SSH.If it doesn't work for you then most likely something is wrong with your COM port, with the board, or with your cable or settings.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 03, 2025, 04:35:10 am
content: I don't know how your AES board is configured, but if the 'HC11 is in bootstrap mode, then PCBug was the program I used.If the 'HC11 is in normal mode, you'll have to burn the hex program (converted from S19 to hex) direct into EPROM using a prom programmer like the TL866 or similar.

author: shabaz
author_rank: Frequent Contributor
timestamp: January 03, 2025, 06:08:19 am
content: In the absence of PCBug (if you cannot obtain that or cannot find a way to run it), all that's required is to shove 256 bytes over the UART, and the microcontroller will place them into RAM automatically, and will then begin execution, it assumes those bytes were code to be executed. It begins execution from address 0 I believe (check the microcontroller reference manual, all this is written in great detail; Motorola were excellent with their documentation).For simple short code that you want to run immediately from RAM, that's sufficient, but if your code is longer than 256 bytes, then you'd write code a kind of secondary bootloader that accepts further bytes, and writes/programs the memory of your choice (RAM, EEPROM, whatever). For instance, you'd write an EEPROM programmer in 256 bytes, which would accept bytes from UART, and write to parallel EEPROM.Or, you'd burn your code to EPROM of course.To get your 256 bytes of code (i.e. either short standalone code you wish to run in RAM immediately, or your secondary bootloader) into the microcontroller, you can transfer 256 raw bytes using whatever terminal program you have (if it supports sending hex bytes from a file) or you can write yourself a simple application (e.g. with Python) that will accept (say) a .s19 file containing your built short application/secondary bootloader, and parses and outputs to USB UART, into your microcontroller (might need a USB-RS232 adapter for old boards, examine your board to determine this).Your secondary bootloader can be smart enough to directly accept .s19 files sent over the USB-serial connection (if you can fit that in 256 bytes). If you cannot, then you could create your own protocol, and write a Python program to take your .s19 file, and convert and send to the board.None of this is very difficult, just needs a day or so examining the reference manual, and the coding can be in your preferred language of choice, but I'd suggest Python would be as reasonable an option as any other.You don't need a terminal program to support s19 format in summary. You can do such file transfers using your own program, and then switch to using the terminal program if you require it for user interaction with the running application (e.g. monitor program or whatever). This was quite a common way of doing things with those (and other) microcontrollers. I used to do the same thing with 68HC11 parts too. I also did it with some Hitachi microcontrollers (i.e., transfer 256 bytes or whatever containing my custom secondary bootloader, and then use that to program Flash memory with more data coming over the UART). It was a useful thing when a dedicated programming tool was not available.

author: Andy Chee
author_rank: Super Contributor
timestamp: January 07, 2025, 06:40:25 am
content: In the interests of software preservation, I'm uploading PCbug here.The main software distribution is contained within pcbug342.zip I've done a quick test in DOSBox 0.74 with a USB-serial converter and the software appears to at least run. I still need to dig out a 'HC11 to test communications.pcbug11a.zip contains a modified executable with delay loops tailored for (back then) fast computers. Not required if you're working in the DOSBox environment, but needed if you decide to run directly in DOS on a vintage platform Pentium 2 550MHz native hardware.Finally pcbug11.pdf is the documentation, which includes a schematic diagram for a minimal system hookup.