Standalone SIO2FLOP (no operating system required)

This program writes an Altair 330K floppy disk with a disk image
transmitted from a PC. The image is transmitted through the 2SIO
serial port at I/O address 010h using the Xmodem protol. The image
is written directly to the floppy in raw format (137 bytes per sector,
32 sectors per track, 77 sectors).

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This version of SIO2FLOP is run by using the front panel or turnkey
monitor to enter a 24 byte loader to read .bin files. Theloader
is then used to read SIO2FLOP.BIN into memory at address zero.

After SIO2FLOP is loaded, reset the computer and run from
address zero. Follow the prompts from SIO2FLOP.

If SIO2FLOP completes without error, a transfer complete message
is displayed and the program loops at an address ending in 0X (octal).

If disk writes fail, no error is displayed and the program
dies in a loop at an address ending in 1X (octal).

If the xmodem transfer fails, no error is displayed and the program
dies in a loop at an address ending in 2X (octal).

SIO2FLOP can be run again by resetting the computer and running
from address zero.

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Here are the octal values for the bin loader. The loader is entered
in memory at 40000 (octal) (set A14 up, all other switches down).


40000: 076 003 323 020 076 025 323 020
40010: 041 000 000 333 020 017 322 013
40020: 100 333 021 167 043 303 013 100


After loading this program, run at address 040000 (octal), then send
the .bin file to be loaded. After the transfer completes, reset the
machine and run from address zero to execute the downloaded program.