Directions for loading IMSAI BASIC (4K or 8K) on a stock S-100 system with Imsai SIO serial card (or equivalent using default SIO ports).
Download BASIC Here
1. Start your system ROM monitor program connected to a PC as your terminal (using TeraTerm or equivalent), and run the tape load command. Usually the tape load command is "L" but consult your ROM monitor manual to confirm. Now your IMSAI is ready to receive the download of BASIC through the serial connection.
2. From your terminal software, send the BASIC .HEX file of choice from the ZIP file link above. Send as a "binary" file (not text/ascii) and add a character transmit delay of 10ms or more to ensure the IMSAI can process the download without error.
3. Watch the download transmit from the PC. Eventually you'll see the BASIC papertape data stream on the terminal screen. Watch for error messages.
4. If you're downloading the 8K version your machine needs 8K to be available as the papertape fills up to address 1FE2, which is nearly the top of 8K (1FFF). BASIC programs are saved from 2000 hex and higher.
5. When the download completes you'll be returned to the ROM monitor prompt.
6. Stop the CPU and change your terminal software to communicate 7N1.
7. Toggle to address 0000, examine, and run. If the download worked, you'll be greeted by a BASIC prompt.