(c)1990 Golden Triangle, Inc.
	(c)1990 Wilson Van Alst
	  All rights reserved.

Fm: Bob Pigford
To: all

I am trying to rewrite one of my M100 Assembly programs to run on my T200.
With the M100, I can pass the cursor over the LCD screen one character
position at a time.  While there (and before the cursor blinks), I can examine
the 6 bytes beginning at 65516 (FFECh) to collect the 6 rows of pixels which
are illuminated.  After flipping them "right side up", I can print or save,
etc.

With the T200, I haven't found the same to be true (yet).  Some of the DL10
source codes refer to the use of bytes beginning at 64864 (FD60h), but they
come out sort of "sideways."  I suspect that the bytes placed in this LCD
"buffer" are not particularly lined up with the normal character values (6
pixels wide x 8 pixels tall).  I have seen others use a CALL to 36468 (8E74h)
prior to looking at the 240 bytes starting at 64864 or a CALL to 36531 (
8EB3h) then a look beginning at 64864 for about 320 bytes.

I really hope to find a way to get the Cursor Byte values just like I can in
the M100 as this will fit my needs well.

Will someone please identify a T200 equivalent of the M100's CURSOR bytes at
65516 or explain the interractions of T200 CALLs and 64864 noted above?

I would greatly appreciate any suggestions anyone would offer.

		- 0 -

Fm: Tony Anderson
To: Bob Pigford

James Yi (73327,1653) left you a message on Thursday, which was wiped out by a
message board crash Friday morning.  Here's the text of the message:

 The difference in how a byte on the LCD screen (is) arranged is as follows.
On the 100, one byte is arranged vertically, all 8 bits representing a pixel.
On the 200, one byte is shown horizontally, and only the least 6 bits appear
on the screen, bit #0 at left most.  The pixel to right of bit #5 is bit #0 of
the next byte. There are 40 bytes per pixel line, and the 41st byte wraps
around to the next line, for 128 lines. When you flash a cursor over a
character, the pixel info there is storead at 64864 (fd60h), the byte
containing the 1st row of 6 pixels is at 64864, the byte for the 2nd row at
64865, etc. To flash a cursor, do this:

        lxi     h,(col-1)*256+(row-1)
        shld    $fea2   ;text row,col
        call    $8cf5   ;show cursor
        call    $8cf5   ;unshow

 and the 8 bytes for 8 rows of 6 pixels that the cursor flashed over will be
stored at fd60h.

 A call to 8e74h either reads or writes 320 bytes of pixel information, which
amounts to 1 line of text. Before calling the routine, L register has the row
number, 1..16, and the Z flag is set to write pixels, cleared to read. The
pixel info is stored at 64864.

 You can use 8eb3h to access individual byte of pixel info instead of 320 of
them at a time.

 But after calling 8eb3h, you have to send i/o commands to the LCD driver
directly to read and write.  See LCDIO.TXT.

		- 0 -

Fm: Bob Pigford
To: Tony Anderson

Thank you for rescuing the lost reply to me from James Yi.  I am now happily
on my way to enjoy applying this GREAT piece of information.  I am most
appreciative.

                - 0 -


Starting message #: 31315   Starting date: 10-Nov-90  20:37:07
 Participants:
Bob Pigford 70431,153
James Yi 73327,1653
Tony Anderson 76703,4062