TRS-Box Serial

TRS-Box Serial Beta

You can now use TRS-Box without the need for a MISE or M3SE. All you need is a serial-IP adapter and a RS-232 interface in your floppy or hard disk enabled TRS-80. Many TRS-80s already have an RS-232 interface installed. You can find them on eBay or from TRS-80 specialists if you need to purchase one. Ask here if you need help finding one.

TRS-Box Serial running on a TRS-80 Model 16

TRS-80 Model III with FreHD and TRS-Box Serial using ATC-1000

TRS-80 Model III with FreHD and TRS-Box Serial using ATC-1000

TRS-Box Serial has been successfully tested on the following platforms:

  • TRS-80 Model 4D 64K with LDOS 5.3.1 and LS-DOS 6.3.1
  • TRS-80 Model III 48K with LDOS 5.3.1
  • TRS-80 Model I Level 2 48K with LDOS 5.1.3 and LDOS 5.3.1
  • TRS-80 Model II/16 with LS-DOS 6.3.1

I am able to achieve consistent and reliable 19.2K baud transmissions on the Model I/III/4 and 9600 baud on the Model II/16 using the ATC-1000 serial-IP converter. At this time, I can’t guarantee it will work on other DOSes or models of TRS-80, but it may. I will be testing on more platforms soon. If you have a particular request or success story with another TRS-80/DOS combination, please let me know.

Remember, this is beta software, so please expect problems.

TRS-Box is free to use during the beta period for the express purpose of copying files to and from your TRS-80. Any other use or abuse of the system will result in blockage or removal of access to the service.
ie. Please don’t ruin it for everyone else. 🙂

TRS-Box Serial Setup

The ATC-1000 TCP/IP to RS-232 converter.

  1. Purchase a serial-IP converter. I highly recommend the ATC-1000 as it is reasonably priced, performs well and I have tested TRS-Box with it extensively. You can also try to use serial-IP proxy software running on a modern PC, however I have not tested this scenario. I prefer to use a standalone adapter as it is really an accessory rather than a whole modern computer and helps to keep the retro feel.
  2. Hook up the serial-IP converter as per its instructions. Important: You need to connect to your RS-232 port with a null modem cable. You also connect the converter to a broadband connected router on your network using an Ethernet cable.
  3. Configure the serial-IP adapter TCP/IP settings to connect to the TRS-Box services:
    Server/Client: Client
    Port: 21
  4. Configure the serial-IP adapter UART settings as follows:
    Mode: RS-232
    Baudrate: 300*
    Character bits: 8
    Parity Type: Even
    Stop Bit: 1
    Hardware Flow Control: None
    Delimiter: CR(13) and LF(10)
    *Make sure the baud rate you specify here is equal to the baud rate you set up using DB SETUP BAUD.
  5. Get the TRS-Box v0.7 beta software here. Copy the correct DB/CMD program for your model of TRS-80 and DOS to your TRS-80. See the README.TXT in the distribution. This may be the most challenging prospect for novice users. There are a myriad of ways to accomplish this task, such as using a PC-Serial transfer program like XMODEM, FreHD, MISE, etc. The good news is that once you have TRS-Box working, you won’t need to perform this task again! As a last resort, we can send you a floppy disk pre-loaded with the program for a small fee.
  6. Test your serial port connection using the following command DB TEST. If you get a success message, then proceed to step 7. If not, then you need to troubleshoot the connection. Here are some things to look for:
    • The problem may be in your settings from step 3 or 4. Make sure they are correct.
    • Check your cables. Are you sure you are using a null modem cable or adapter? You may want to obtain an RS-232 tester.
    • Your internet connection may be blocked. Make sure your router allows port 21 traffic out from the serial-IP adapter.
    • It not uncommon for the UART on the RS-232 interface to go bad, so you may have a hardware problem.
  7. Log into TRS-Box on your PC or Mac here using your Dropbox credentials. You will notice that you sign into Dropbox on the secure Dropbox website. TRS-Box never sees your Dropbox username or password. TRS-Box will also only have access to a special folder in your Dropbox called “Apps/TRS-Box”. This is where you will put your TRS-80 files.
  8. Once you obtain the TRS-Box token, type DB SETUP TOKEN YOURTOKEN.e.g. DB SETUP TOKEN 1234567890 If you see a success message then you are ready to use TRS-Box! Keep in mind that the token will expire from time to time so you may need to re-login occasionally.
  9. Type DB ? to see the various commands and options.
  10. Have fun managing your TRS-80 files!


Start at 300 baud to make sure everything is working ok. Keep in mind that large files will take a long time to transfer using 300 baud. For 300 baud, every indicator “.” (period) that shows up during the transfer process represents 64 bytes.
To find your maximum reliable transfer speed, ramp up the baud rate in succession from 300 to 1200 to 2400, etc. and test your transfers at each step. Once you get to a speed that no longer transfers reliably, then back down to the previous speed. This should be considered the maximum transfer speed for your particular setup. The maximum speed is affected by many factors, including the speed of the CPU and the capabilities of your serial-IP adapter.

TRS-80 Model 4D running TRS-Box Serial with a ATC-1000 Serial-IP converter.