Re: Several answers (3)

From: Larry Anderson (
Date: 1998-04-01 20:49:06

Andre Fachat wrote:
> > > After all by switching the _charrom_ to graphics mode....
> > How this is done on the PET? I found out by poking 59468,12. but that
> > (certainly) is not the friendly way to do it.
> As far as I know (probably PETdoc or pet-FAQ prove me wrong) this is the
> only way. Probably there is a PRINT CHR$(??) as in the C64.
On the 4.0 ROM PETS you can swith to Upper/Lower Case by PRINTing CHR$(14) and
back to graphics by CHR$(12).  All older ROM versions required the POKE to 59468.

Also to note, PRINTing CHR$(14) on the 'Fat Forty' (possibly also 8032)
adjusts the line spacing so there is a two-pixel gap between lines, the same
effect cannot be accomplished by POKE 59468,14 alone.

On the Screen blanking Discussion:

  PET Revealed reveals that the blanking is only available on the static-RAM
PETs only (i.e original motherboard)  Mention is made of its use during
"character entry and retrace.  This prevents the broken characters which
appear on the screen during PEEK and POKE operations, due to interference
between the character generator addressing and the processor addressing. The
screen blanking function can be used in machine code programs to give a nice
clean display free of interference, in Basic programs it can be used to
suppress the display until a whole screen full of information is present. The
commands in Basic to produce screen blanking are POKE 59409,52 and to restore
the display POKE 59409,60."

Larry Anderson - Sysop of Silicon Realms BBS (300-2400bd) (209) 754-1363
Visit my Commodore 8-Bit web page at:

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