RE: Success - first hires graphics ;)

From: vossi <vossi_at_ceffy.de>
Date: Wed, 6 Sep 2017 23:41:23 -0700 (MST)
Message-ID: <1504766483671-0.post@n4.nabble.com>
@Ruud:
I will read the 6545 datasheet to better understand why the screen starts at
$0000.
...also I take a look at the IBM CGA adapter - it uses the same 6545 with
640x200  pixels graphics mode.

Mix-mode:
It seems like the board disables the char-rom, if there is a SPACE character
and reads the bytes from the graphics RAM. If a character is in screen
memory the character has priority!
All character-rom pins are wirde to the socket except pin21. Here it seems
to disable  the rom. This is CS3 at the 2316 rom but I have an 2716 eprom
and this has here VPP. OK, vpp should be at +5V normally, is the eprom
disabled with GND at VPP???



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Received on 2017-09-07 07:00:32

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