[Coco] D.L. Logo question

Joel Ewy jcewy at swbell.net
Thu Nov 22 21:22:51 EST 2007

Robert Gault wrote:
> Let me start by saying I don't know the Logo language and never used
> it until the following occurred.
Hey, Robert,

I have the opposite problem you have.  In '98 or '99 I bought a copy of
D.L. Logo at the CoCo Fest.  Got it home to discover there was no floppy
disk in the box.  Not a big deal 'cause I only paid about $5 for it, but
still a little disappointing.  I also don't know Logo from Mongolian,
but I do have the box, the 406-page manual, the software registration
cards -- even the floppy disk envelope containing an unused sticker with
the title and catalog number -- just no disk.
> I was given a disk image of what I believe is the original D.L. Logo
> disk for OS-9 Level-I. The disk contains a Demo program and several
> data files that are part of Demo. I been testing the disk image in
> MESS and the odd thing is the program won't run as written; Out of
> Memory Error.
> If this program was supplied with D.L. Logo, it is strange that it
> won't run as written. The best I've been able to do is start Logo as
> follows:
> logo #24K
> After boosting data memory (default is about 10K) the program will at
> least run a single pass to completion. However, the program is written
> to repeat in an endless loop. With 24K, the program runs out of memory
> on the second pass. I've not been able to give logo more memory nor
> get the program to run through more than one pass.
> Can anyone owning D.L. Logo provide information on the above? Were
> there instructions in the owner's manual on increasing the amount of
> memory available to Logo? Is there some garbage clearing command for
> Logo which should be used in the program after each pass?
Here's an excerpt from the manual:

"To let D.L. LOGO show off, leave your backup diskette in Drive 0, and
type the following as your first command:


The blue cursor disappears, and Drive 0 runs for a few moments.  When
the blue cursor reappears on the screen (your screen shows a question
mark (?) followed by a blue block), type:


If you have a Speech/Sound cartridge installed, the demonstration
program greets you audibly, as well as on the screen display, and speaks
to you throughout the demonstration.  Sit back and enjoy the display. 
When the program ends, it repeats itself.  To stop the program, press

This is on page 6 of the manual.  On page 5, it simply says to start
LOGO by typing "LOGO [ENTER]" at the OS-9: prompt -- no special
instructions for starting it up with extra memory.

It looks like you can erase all procedures in memory by issuing the
ERALL primitive, or erase specific procedures with 'ERASE "filename
[ENTER]'.  You can see the names of all procedures in memory with POTS,
and you can Print Out (to the screen) a procedure with 'PO
"procedurename'.  POALL will print out all procedures in memory.  These
commands might give you an idea what's loaded up when you start LOGO,
and after you load DEMO.  Maybe your disk image is somebody's customized
working copy that auto-loads a bunch of procedures on startup?
> It seems to me that the demo program chews up data space with
> recursive routines. I've no idea if Logo has memory flooding or what
> it does to clear data memory when a recursive program ends (if
> necessary).
You can use TRACE [n] to have it list the program lines as it executes. 
NOTRACE turns it off.  The optional parameter specifies how many lines
it will execute before waiting for the user to hit the spacebar and
continue the program (1-255).  If the parameter is omitted, the program
does not pause.

Don't know if that's helpful, but it might give you a few clues.  I
would offer to scan the manual for you, but as I said, it's over 400
pages long!  There's probably generic Logo information out there on the
Web, but if you have OS-9-specific questions, I can look them up for you.

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