Re: Apple and the Holy War

[dempson@actrix.gen.nz (David Empson)]

Paul Schlyter <pausch@saafNOSPAM.se> wrote:

> In article <1eaal0q.16krdx01sadwhoN%dempson@actrix.gen.nz>,
> David Empson <dempson@actrix.gen.nz> wrote:
>  
> > No it didn't.  The 6800, 6802 and 6808 have A and B accumulators, but
> > don't support the combined 16-bit D accumulator, and hence don't have
> > the MUL instruction.  (I just confirmed this in the 6802 data sheet.)
> > 
> > You are probably thinking of the 6801 or 6803, which do have this
> > feature.  (Or the 68HC11, which is derived from the 6801.)
>  
> You're right -- I was actually thinking of the 68HC11.  I'm not
> really that familiar with the differences between the 6800, 6801,
> 6802 and 6803.  Thanks for pointing this out.

If you care:

6800 is the base version: a simple microprocessor.

6802 is identical except that it has a built-in oscillator, which
simplifies the clocking arrangements, and some internal RAM.  There is
also the 6808, which is the same minus the RAM.

6801 is a single chip microcomputer, with built-in ROM, RAM and some
peripherals (serial port, parallel I/O, timer).  It also has CPU
architectural improvements such as the D register and associated
instructions.

6803 is a ROM-less version of the 6801.

(I programmed the Hitachi 6301/6303 at work for many years - they are a
derivative of the Motorola 6801/6803.)

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand