* * HARDWARE OVERVIEW * *
uTerm-S (micro-Term Stand-alone) is a legacy RS232 VT100-like terminal.
It is the stand-alone version of uTerm, the terminal board for the Z80-MBC2 (https://hackaday.io/project/165325).
uTerm-S has a VGA out and PS/2 keyboard connector, a RS232 port, a power supply and a "transparent" serial-USB port.
Here three uTerm-S in action during a crazy experiment of a VHDL Z80 computer running MP/M with 4 concurrent users/terminals using my custom HW:
THE "TRANSPARENT" SER_USB PORT (J3)
The uTerm-S has a "transparent" USB-serial adapter connector, so you can e.g. use XMODEM to exchange files with a PC (running a terminal emulator that supports XMODEM file transfer) while the uTerm-S is in use.
Both the "mixed" power supply scenarios (USB-serial adapter not powered from USB but uTerm-S powered and vice-versa) are managed by the HW, so you don't need to worry about it. In the following photo a serial-USB adapter is connected with a cable to the transparent SER_USB port:
This allows to use two keyboards and two monitors in the "same" time (one keyboard and monitor attached directly to the uTerm-S, and another keyboard and monitor of the terminal emulator on a PC connected with the serial-USB).
Or you can use the monitor attached to the uTerm and the keyboard of the terminal emulator on a PC. Please note that the SER_USB port support both the RTS/CTS HW handshaking, so to use them both RTS/CTS signals are needed on the serial-USB adapter:
CHANGING THE RS232 SPEED (J1)
It is possible choose among 3 baud rate (the most common ones) using a jumper on J1 (AUX) as shown in the following image:
CHANGING THE COLOR (JP2-JP3)
It is possible choose among 4 colors (green, white, cyan, amber) for the output VGA signal. To select the color use the JP2 and JP3 jumpers. In the following photos are shown the setting for JP2 and JP3 to select the color as white or green respectively:
THE RTS-HS SWITCH (SW2)
The RTS-HS switch is used to turn on or off the RTS handshaking.
When turned off, the host connected to the serial port will see the RST line always active. This can be handy in various situations.
If RTS-HS is always off you don't need to connect it on the serial-USB adapter.
HOW TO FLASH THE STM32 WITH THE ST-LINK V2
The flashing procedure is the same of uTerm. So refer to the same paragraph of the uTerm page taking into account that here the SWD connector is marked J3 instead of J6.
* * HOW TO GET A PCB * *
I've prepared an "easy link" to order a small lot (min. 5 pcs) of PCB here.
* * HOW TO GET A KIT OR AN ASSEMBLED UNIT * *
If you are looking for a kit with all the needed parts (including the 3D printed parts) or an assembled unit ready to use there is a professional seller that can sell both and ship worldwide.
The link to the seller is this one.
* * CREDITS & LICENSE * *
The video terminal is based on the ChibiTerm by K. C. Lee (https://hw-by-design.blogspot.com/2018/07/low-cost-vga-terminal-module-project.html).
VT100 emulation was added by Madis Kaal (http://www.nomad.ee/micros/chibiterm.shtml).
Thanks to gkaufman of the Retrobrew Computer Forum for a bug that has been discovered and solved by him.
All the project files are licensed under GPL v3.
Hello, I built the project and now there are some issues. When I connect my Z80MBC2 to the "USB Serial J3" there is no response. When I connect a PC via FT232 Adapter it works fine in the direction to the PC, but it has many errors when receiving from the PC. With a Oscilloscope at pin 12 of MAX232 and pin 18 of the STM, the signal looks fine. It seems as if the STM do not work properly. Has someone an idea?