Makey@LOGICON.ARPA (Jeff Makey) (01/06/88)
I have been experimenting with display lists on my 800XL and have
encountered a couple of strange problems. The first is that if I try
to use the very bottom scan line on the display, the picture rolls.
Adjusting the vertical hold on the monitor doesn't help. There doesn't
seem to be a sync signal, or something, as I can slow down the roll to
*almost* a stop, but it doesn't latch into position when it should.
There is no problem with using the top scan line of the display.
The second problem occurs when I try to use a wide playfield. In this
case, the 3 leftmost columns on the display show the border color
instead of the background color or any text that is there. On the
right side, the last column is non-existent (black) and the
second-to-last column has a moving snow-like appearance. Once again, I
have tried adjusting the monitor but it doesn't help. I am not just
running off the edge of my CRT.
Some notes: I bought my 800XL, serial number 189429, in June 1986. It
has the GTIA chip, "B" OS ROMs, and all of this happens with an Action!
cartridge plugged in. I use a B/W composite monitor, not a TV.
Has anyone seen anything like this before? Is it an inherent problem,
a configuration problem, or just my breath?
:: Jeff Makey
Makey@LOGICON.ARPA