Re: [hatari-devel] New SCC 85C30 support for MegaSTE/TT/Falcon

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 15/09/2023 à 01:23, Eero Tamminen a écrit :
> Hi,
>
> On 14.9.2023 23.50, Nicolas Pomarède wrote:
> > they don't differ that much. They all have in common the regs 
> > FF8C81/83/85/87 and the TT has some extra regs :
> >
> >   - a bit to switch port A between 1 RS422 LAN port (MiniDIN, 8 pins) 
> > and 1 RS232C serial port A (DB-9P, 9 pins). Not supported yet
> >
> >   - some regs at FF8C01-FF8C15 to handle dma transfer with SCC. Not 
> > supported yet. Are there some TT programs that make use of this ? 
> > (Emutos maybe ?)
>
> EmuTOS detects SCC:
> https://github.com/emutos/emutos/blob/master/bios/machine.c#L182
>
> And seems to support SCC serial:
> https://github.com/emutos/emutos/blob/master/bios/serport.c#L480

Hi

I saw that in Emutos code, the new SCC should support all the 
modes/registers that Emutos uses.

> > Also not emulated yet is to connect TT's MFP timer C as an external 
> > clock for the SCC.
> >
> > As you often use/work with linux for Atari, do you know if it uses SCC ?
>
> Hatari's partial SCC support has been enough to boot Linux on Falcon, 
> but on TT it would require VME SCU support, that is still missing from 
> Hatari.
>
> As you can see from this:
> https://github.com/torvalds/linux/blob/master/arch/m68k/kernel/head.S#L2744

Indeed, SCU support is far from complete, vme.c is full of "TODO" ;)

> > > I'm not sure where to fit SCC options in SDL GUI though, "Devices" 
> > > dialog is pretty full...
> >
> > yes, it's rather crowded :) Maybe add some intermediate options' screen ?
>
> You mean separate "Serial config" dialog invoked from the Devices dialog?

yes. It would add one level of dialog, but the more options we add, the 
more difficult it is to fit everything on the existing dialogs.

Nicolas