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Comment by ruslan | Hacker News Reader

I think in this particular (macbook) case the problem was lack of proper software. Yet, I recall if there was modem installed, a terminal software had to be present as well.

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The CP/M side didn't have any terminal software. Both sides had methods to set 9600/n/8/1 on the printer device.

On the PC side, without PROCOMM, it would be possible to "COPY COM1: FOO.TXT" but I don't know how 9600/n/8/1 could be set in advance (IIRC setting it as a printer to force the baud rate altered the device so it could not be read).

Generally speaking, all of the pre-PC microcomputers implemented serial ports, which is the first choice in pulling data off of them (including binary data with XMODEM and its variants).

Yes, you can transfer files via COM port in MS-DOS using COPY command, but errors may occur. :) Also you have to switch port to 8-bit binary mode and turn off flow control. Don't remember how to do that exactly. Default was 7 bit XON/XOFF, AFAIR.

Looks like it's the MODE command: https://home.csulb.edu/~murdock/mode.html

Is it so hard to write your own program which would just read a file stream and send it to a port? Maybe also split it into smaller frames with CRC hashes attached.

Depends: I wonder what programming tools/languages were present on the old PowerBook. Otherwise, getting any handwritten program or its associated tools/runtimes (if necessary) onto the laptop might be just as much of a challenge as getting audio data off.

Just program directly on the macbook! :D would be fun to experience imo

`cat file > /dev/com1`, or something like that.

Isn’t this a pre unix mac?

CP/M was an OS for the 8080/Z80, which was limited to 64k of RAM.

None of the tools that you know today would work in something that small.

There was a C compiler for a dialect of C that met these constraints; I didn't have it, and I didn't know C at the time.

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