Date   : Sat, 12 Jun 2004 16:49:46 +0100
From   : Sprow <info@...>
Subject: Re: Solid state storage for the beeb

In article <gr3mc0dgf0ts8gseb2kaps5kbmqnk4ns73@...>,
   John Kortink <kortink@...> wrote:
> On Sat, 12 Jun 2004 13:11:01 +0100, Sprow <info@...> wrote:

> >What would be really great would be a 1770 emulation layer
>
> I don't doubt that'll happen. 

Shame. Still, I guess as long as you're prepared to detail how to talk to
the CPLD then I can always knock out a driver - as the 1770 driver in DOSFS
is abstracted already (um, I think it is [fx:checks] ah yes, all in one
file) it doesn't really need a 1770 emulation layer just time for me to
write an MMC driver.

Oh, and support for partitions.

[snip]

> >I must say I'd be a little surprised if you can get 64kB/s over what is
> >effectively a synchronous serial link, the 24bBC RAM disc musters about
> >20kB/s using the 1MHz bus with a really tight loop - if the beeb is 
> >running about 0.5MIPS then you'd have to be slurping one byte every 8 
> >instructions.

> Yes, but the interface optimization I mentioned entails
> conversion of the serial link to a parallel one (by using
> a CPLD between beeb and MMC). 

Ah ha - a CPLD. Nice.
Now 64k all makes sense, I was originally intending on using a PIC with an
SPI port and parallel R/W port facing the beeb.

So which port does the GoMMC plug into? Surely not the disc interface?
Sprow.