Character Generator ROM data - test-drb@ccmp.vtda.org

21 Oct 2005

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Subject: Character Generator ROM data
   From: Chuck Swiger <cswiger at widomaker.com>
   Date: Fri, 21 Oct 2005 21:47:44 -0400
     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>

Gang -

    Anybody know of readily available data for, say, 7x9 dot-matrix characters?
I'm looking for a downloadable rom image for something like in old video 
cards to
paint ascii characters on a display.

For example, my Polymorphic Systems Video Terminal Interface (VTI) card uses
an  MCM6571A (or it could use a 6574)   -BUT-   I do not need exactly that
font - any 7x9 data will work.    Spent the past hour trying terms in 
google w/o
anything usable turning up. 
Is simple.  Find a pattern you like in row or colum scan and convert the 
bit pattern to a string of hex values and cook an Eprom/EEPROM.

Myself I needed a while back a 7x9 that had decenders one of the M6571 
series has that so I found that data sheet.  They fit easily into a 2716
or similar.  

Hint where they go in rom is based on SxC IE: number of scan lines typically 
11 or 12 for 7x9 fonts and the number of characters.  For 7x9 CRT fonts 
(ROW scanned) the low 4 addresses lines are the row data and the next 7 
(128 char font) are the character address.  Nothing magic.

Allison