TRS-80 Model 100

The Model 100 (1983) was a portable computer designed largely by Bill Gates — reportedly the last product he personally coded. It features a full keyboard, built-in 300-baud modem, and runs on 4 AA batteries for 20 hours.

The built-in software in ROM includes: BASIC, a text editor, an address book, a scheduler, and a terminal program (TELCOM).

TS-DOS

TS-DOS is a disk operating system for the Model 100 that provides CP/M-compatible file management when connected to a disk system.

FILES       List files
LOAD "file" Load BASIC program
SAVE "file" Save BASIC program
KILL "file" Delete file

DosBox (for PC file transfer tools)

When using old PC-based transfer utilities, DosBox provides an MS-DOS environment:

# Install
apt install dosbox

# Run DOS program
dosbox /path/to/program.exe

File Transfer via TELCOM

The Model 100’s TELCOM program allows file transfer via serial:

TELCOM Settings

TERM    Terminal mode (interactive)
UPLOAD  Send file from Model 100
DOWN    Receive file to Model 100

Transfer with XMODEM

On the host computer:

# Receive file from Model 100 (host side)
rx -v filename.bas

# Send file to Model 100
sx filename.bas

In TELCOM on the Model 100:

M8N1E   Set modem parameters (8 bits, no parity, 1 stop, echo)
TERM    Enter terminal mode

Built-in Modem

The 300-baud modem connects directly to a phone line. With TELCOM:

TELCOM
CALL 555-1234   Dial a number

In the 1980s, Model 100 users filed stories directly from the field to their newsrooms via the built-in modem — it was a favorite of journalists.