Re: conversion of cbm8032 video signal to vga or hdmi

From: Daniel O'Shea <dan_at_ozramp.net.au>
Date: Wed, 3 Nov 2021 19:59:07 +1030
Message-ID: <CAOUppuPKq8PiF9BVwS7g-zZHKS0_O2T+NVvwk10C1p1HvhmSdQ_at_mail.gmail.com>
Another way of approaching this may be to have the FPGA stand-in for the
6545 and grab the video data directly? Some inspiration:

https://github.com/EisernSchild/MC6845
https://github.com/schlae/graphics-gremlin/blob/main/verilog/crtc6845.v
https://opencores.org/websvn/filedetails?repname=System09&path=%2FSystem09%2Ftrunk%2Frtl%2FVHDL%2Fcrtc6845.vhd

On Wed, 3 Nov 2021 at 19:44, <didier_at_aida.org> wrote:

> I'm on a project to convert the signal from video connnector of a cbm
> 8032 into a vga or hdmi signal
>
> the idea is to use a fpga   MAX10 or ICE40UP5k to grab the commodore
> video signal and convert it into a vga or hdmi
> actually I'm producing the vga signal and I'm trying to grab the cbm signal
>
> I'm looking for these informations...
> the pixel clock
> the total count of pixels clock on a line
> the count of visible pixels on a line
> the width of the horizontal synchro (in pixel clocks)
> the count of pixel clocks in the horizontal front portch
> the count of pixel clocks in the horizontal back portch
> the horizontal synchro polarity
>
> the total count of lines in the screen
> the count of visible lines
> the width of the vertical synchro
> the count of lines in the vertical front portch
> the count of lines  in the vertical back portch
> the vertical synchro polarity
>
>
> to do this conversion I use an internal ram in the fpga for a 640x200
> pixels screen
> the conversion to hdmi is done with a PMOD to HDMI adapter using a texas
> chip...
>
> the idea is to be compatible with all the cbm and cbm II
> I'm developping on a DE10-Lite board but I'll move the final version to
> a icebreaker board + pmod to hdmi adapter
>
> I checked serveral sources from zimmers and Steve's data form the CRTC
> but till know it's not so clear...
> if you have any idea ?
>
> thanks
>
Received on 2021-11-03 11:05:06

Archive generated by hypermail 2.3.0.