Re: Questions about the 8563 / 8568

From: Richard Atkinson <ratkinson77_at_icloud.com>
Date: Fri, 16 Dec 2022 09:15:35 +0000
Message-Id: <8B386F40-601C-4FFB-8EC2-23FCD6037EE1_at_icloud.com>
Hello Ruud, it’s been a while :)

> On 16 Dec 2022, at 09:04, Baltissen, GJPAA (Ruud) <ruud.baltissen_at_apg.nl> wrote:
> 
> - I only noticed now, and that after 30 years, that I don’t see any character ROMs that provide the 8563 and 8568 with data. Do they have build-in ROMs or am I missing something?
> 
The character data is copied into the VDC’s RAM from the C128’s main ROMs. On a German C128, the CAPS LOCK key becomes an ASCII/DIN key, for US and German character sets, and there is a noticeable delay in the response to the keyboard in BASIC when you press it or release it, as the relevant character set is being copied into VDC RAM.

>  
> 
> - The 8568 has a composite video and sync pin. Does this mean that the DCR outputs a color composite signal?
> 
>  
> 
I wouldn’t have thought it would be colour, because the VDC doesn’t have a PAL or NTSC colour subcarrier derived clock (some multiple of 3.58 MHz or 4.43 MHz) but rather a 16 MHz clock. But it might well output a monochrome composite video signal.

Richard
Received on 2022-12-16 11:02:53

Archive generated by hypermail 2.3.0.