From: Christian Johansson (c64_at_comhem.se)
Date: 2004-06-21 19:51:54
----- Original Message ----- From: "MagerValp" <MagerValp@cling.gu.se> To: <firstname.lastname@example.org> Sent: Monday, June 21, 2004 7:13 PM Subject: Re: RS-232 on VIC-20 > >>>>> "CJ" == Christian Johansson <email@example.com> writes: > > CJ> Has anybody been able to use the Hug RS-232 routines to get 4800 > CJ> bps on the C128? I think it should be possible since if it is > CJ> possible to achieve 2400 bps on the C64 in 1 MHz with the > CJ> routines, it should also be possible to achieve 4800 bps on the > CJ> C128 in 2 MHz > > Well, actually, the biggest problem is badlines - and they're 40 us > long even in 2 MHz mode. In 80 column mode with the VIC screen closed > it's possible to use 9600 bps though. > I'm not very familiar with badlines. Does that problem exist even if I blank the screen in 40-column mode? Of course, I blank the screen when using the 40-column mode with 2 MHz because there is not much point in seeing a lot of garbage moving across the screen. Anyway, I have tested that it is only possible to achieve 2400 bps with the built-in Kernal routines in 2 MHz mode and 80-column mode but I know that it is possible to achieve 9600 bps using custom routines (and 115200 bps if you stop using interrupts and use code like in Over5). What I want to know is if the Hug routine I posted in my previous email could perhaps be used to get at least 4800 bps by making some small modifications to it. I think it should be enough to change the definitions of the bit times but as I wrote I don't understand how they have been calculated. Message was sent through the cbm-hackers mailing list
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