Character Generator ROM data
ajp166 at bellatlantic.net
Fri Oct 21 21:28:17 CDT 2005
>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>
> 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
>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
>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
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.
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