Date   : Sat, 28 Aug 2010 14:18:49 +1030
From   : station240@... (paul aslin)
Subject: Does MOS 4.0 work properly in a full Master ?

> Date: Fri, 27 Aug 2010 18:59:26 +0100
> From: jgh@...
> To: bbc-micro@...
> Subject: Re: [BBC-Micro] Does MOS 4.0 work properly in a full Master ?
> 
> paul aslin wrote:
> > I'm considering making a new 1mbit rom using MOS4.0, and adding   
> > ADFS, DFS and anything else needed. Point being it originally is a   
> > 512kbit rom, so installing it as the top half of a 1mbit rom leaves   
> > 4 unobstructed 16kbit rom slots.
> 
> Why MOS 4 exactly?
> 
> MOS 4.xx is a 32K MOS in ROM 15 and the C000-FFFF OS space.
> ROM 14 and 13 can be replaced with absolutely anything. So,
> if you put MOS 4 into an 8-bank ROM instead of the 4-bank ROM
> it normally lives in, you've got ROMs 9,10,11,12,13,14 that
> you can put absolutely anything in without worrying about
> the MOS 3 code that overflows into ROM 9. That code is now
> in ROM 15 by virtue of TERMINAL being chucked out.
> 
> I haven't got around to looking into it in detail, but are
> you sure the Tube code is in MOS 4?

Well considering I'm using that machine i0.s station 254 and  Level 3 doesn't
start unless the 6502 2nd processor is working.

> I though MOS 4 chucked
> away all the drivers for everything. I seem to remember
> people ended up putting MOS 3 into Master ETs so they could
> use the analogue and serial ports.

I can quickly make up a comm cable easy enough, but looks like I'll have
to shove wires and resistors into the Analog port to test that.

And yes I know about the odd jumper I have to makeup to use a 512kbit rom. 

> I'd recommend:
> 
> a patched DFS that allows you to do double-density access
> from OSWORD 7F (eg DFS2.24+). In fact, I'd recommend DFS2.24+Mse
> which has Mouse drivers in the spare space.
> (see http://mdfs.net/System/ROMs/Filing/Disk/Acorn)
> 
> ADFS 1.53 - gives you access to IDE devices, ADFS 1.50 is only
> useful if you really really want to use a SSCI hard drive.
> (also http://mdfs.net/System/ROMs/Filing/Disk/Acorn)

I actually do have a SCSI hard drive, well the vital parts of one, just need
a MFM drive and a few cables.
Ideally I should have both ADFS versions in one machine, but hey I have econet
for a reason.

> BASIC 4.32 or later. John Kortink has fixed a couple of bugs in
> BASIC 4.32, I haven't got around to adding it to my archive yet.
> (see http://mdfs.net/System/ROMs/Language)



> For consistancy with other arrangements, I would also recommend:
> if you include VIEW - put it in ROM 14
> if you include ADFS - put it in ROM 13
> if you include BASIC - put it in ROM 12
> if you include DFS - put it in ROM 9

Good point about rearranging the ROMs, means standard CMOS ram config will work.

What is strange, is when I put a MOS 3.2 version of DFS into slot 9, the
*HELP SRAM commands work again. I wonder what else it fixes.