Minimal CP/M SBC design?

Roy J. Tellason rtellason at
Mon May 5 08:26:12 CDT 2008

On Sunday 04 May 2008 23:54, dwight elvey wrote:
> > From: ethan.dicks at
> >
> > I am a little unclear, though, about how traditional CP/M systems
> > were set up for ROM and RAM. Was it common to use a "shadow ROM"
> > in low mem at reset, then have the BIOS live at the top of memory?
> Hi
>  Most ROM based machines do some kind of shadow method to boot,
> unless one has a front panel to select the boot address.
>  Other than that, there is no particular reason to shadow the high
> memory ROM.
>  My CP/M system is completely RAM. The disk is DMA and has
> a built in boot strap boot from disk. No ROM at all in my machine.
> Dwight

How does that bootstrap work,  then,  with no ROM?

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