Another ~1960 computer kit

From: Megan <>
Date: Sat Dec 19 22:29:53 1998 (Tony Duell) wrote:

>; Tape player - a trivial music program for the P850
>; Written 1987 by A.R.Duell, and placed in the Public Domain.
>; Reads a paper tape from the standard reader (a Trend HSR500interfaced
>; to the PTR card). The tape contains pairs of bytes which define the
>; pitch (in number of empty loops per half cycle) and duration (in number
>; of cycles). This program produces sound by toggling the LSB of the
>; Digital I/O (DIOC) unit
>; As few other users know P850 assembler, I'll try and explain the
>; instructions

If I remember correctly, this is exactly how the hackers at Stanford
got the DECsystem-10 to play music, but toggling the low-order bits
of the AC (Bits 30-35) and driving a speaker. This gave them 6
'voices'. Someone developed a music compiler and there was a lot
of music entered by various people...

My favorite was 'Bumble Boogie'.

About 15 or so years ago, a friend of mine wrote a compiler for the
same music files in -11 macro, and I (knowing a little more music
than he) entered a number of pieces. I entered some like Beethoven's
Moonlight Sonata and Joplin's Crush Collision Rag.

I wish I could find that compiler again... I still have LOTS of
the music files.

                                        Megan Gentry
                                        Former RT-11 Developer

| Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry! |
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Received on Sat Dec 19 1998 - 22:29:53 GMT

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