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July_1999
Re: 6808 <-> 6800 (off topic)

From: Zonn ( )
Date: Thu Jul 15 1999 - 15:23:50 CDT

On Thu, 15 Jul 1999 16:03:04 -0400, you wrote:

>
>
>The 6808 is a ramless 6802 so the instruction set should be identical. I'm not
>sure how they relate to the 6800 and 6809.

And the 6802 was the 6800 with built in osc control. The 6800 needed
external oscillator circuitry.

So (from memory)
   6800 = No RAM, no OSC control
   6802 = RAM, OSC control
   6808 = No RAM, OSC control (never used one of these)

I don't believe the instruction set on these changed until the 6803,
which added some D instructions (The combination of A and B registers
treated as one 16 bit register), which included a MUL instruction.

The 6809 had similar mnemonics to the other 680x series, but the
instructions (opcodes) were very different.

-Zonn

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