Cassette BASIC question

MoonHound · Joined: 26 Nov 2007 Posts: 1

I have a cassette with an old program from high school written on a TI 99 /
4 (which is not available to me now). How could I retrieve it? Maybe I
could record it into a wav file. I have some old version of BASIC on hand
that might be compatible, QuickBasic and VBDOS. But how would I import the
sound file into them or change it back to code? Thanks.

Archived from group: microsoft>public>vb>dos

Dick Grier · Joined: 04 Oct 2007 Posts: 238

Hi,

Tricky.

This files used FSK (Frequency Shift Keying) encoding at 300 baud (usually),
and if the data is ASCII, not binary, you MAY be able to recover it. If I
recall, a "1" would be 1200 Hz, and a "0" would be 600 Hz, with standard
8-bit serial format (1 start, 8 data, 1 stop, and no parity). If so, then
it would be possible to record this to a wave file and to write a program to
decode the FSK.

I haven't done it, but this might get you started.

BTW, I did design a simple circuit that did this decoding more than 25 years
ago. Its output was serial RS-232, and functioned because the encoding was
as I described above. I haven't seen the board that I designed in recent
years, and don't have a copy of the schematic, so my memory is my only
resource.

Dick

--
Richard Grier, MVP
Hard & Software
Author of Visual Basic Programmer's Guide to Serial Communications, Fourth
Edition,
ISBN 1-890422-28-2 (391 pages, includes CD-ROM). July 2004, Revised March
2006.
See www.hardandsoftware.net for details and contact information.