[net.micro.cbm] "80 column"

191622291@excalibur.UUCP (Simon Francis E) (03/16/86)

HELP!!!

I have been trying to find a way to set the commodore 64 into 80 column
mode.   I have seen it done. <normally half res> .  Does anyone know
the routine that is needed to set it in 80 col, using software.  If not is there
any Hardware available that will do it??  <if so do you know a approx.
of the cost>

                            Fran Simon
                            !ihnp4!psuvax1!vu-vlsi!excalibur!191622291


             ----------------------------------------                  
                "No one was ever born depraved!!"
             ----------------------------------------

randy@ranhome.UUCP (The Master of the House) (03/19/86)

> 
> 
> I have been trying to find a way to set the commodore 64 into 80 column
> mode.   I have seen it done. <normally half res> .  Does anyone know
> the routine that is needed to set it in 80 col, using software.  If not is there
> any Hardware available that will do it??  <if so do you know a approx.
> of the cost>
> 

Batteries Included makes an add on card called the BI80.  It provides 80 cols,
but the only commercial software that I have seen that works with it is the
Paper Clip word processor by the same company.  Compute magazine once
published a program to provide 80 cols in software.


(Randy Horton)      allegra|                        
		    hplabs |                        
		    topaz  |-!pyramid!ranhome!randy 
		    decwrl |                        

stuart@tellab1.UUCP (Rick Stuart) (03/22/86)

(TO: Simon Francis E)

Fran...

You can find a listing of an 80 column program in  the  September
1984  issue of Compute!'s Gazette.  The article is on page 48 and
the program starts on page 158.  The program is 3660  bytes  long
and  is  all in machine code (so start typing now!). As you might
know, the characters on a commodore 64 are  displaied  in  a  8x8
grid  pattern.   In order to double the horz density of displaied
characters, you need to use a 4x8 character format.  This, howev-
er,  looks  like  latin  on the best of monitors, and is how most
software 80 column programs (like the one in Compute!'s  Gazette)
works.   The  alternative  is  to  get  a  hardware fix. I really
haven't priced 80 column hardware adapters,  but  I  would  think
they  would  run about $70 to $120.  Of course you need a monitor
that can handle the  increased  band-width.   Band-width  roughly
represents  the  number of dots displayable during a given amount
of time.  Color TV's have a band-width of about  3.5  MHz,  B&W's
are  around 4.0 MHz and good monitors run about 12.0 MHz.  A lit-
tle math and you will find you  need  about  11.3  MHz  worth  of
band-width to display 80 columns.

15720x80x6x(3/2) = 11.3 MHz

where:

        15720 - Horz Freq
           80 - column
            6 - dots/char
        (3/2) - total scan/displayed scan

So in the end you need the hardware fix (about $100) and at least
a  11.3  MHz  monitor  (about  $100 for black & white or $400 for
color).  All together that's $200 for the B&W system and $500 for
the color. One other point, I'm not certain but I think that most
of these hardware 80 column adapters aren't in  color  anyway  so
save your money and get the B&W monitor.

Have fun and good luck...

			Rick Stuart
			Tellabs
			Lisle, IL