>
>        I would suggest you begin with the ATMEGA8. It has more RAM, I/O
>and speed. And you can use the straight parallel port connection.
>        As a bonus, it has a 2 clock cycle 8x8 multiplier! It means you
>can do an 8x8bit product in 125nS running at 16MHz!
>        It costs a little more than the AT90S2313.

Internal RC oscillator is nice too.

I did a printer controller with this chip, running a 4" thermal printhead at full rated speed. The burn compensation makes extensive use of the FMULT instruction, a fractional multiply. I adjust burn pulse width dependent on battery voltage, head temperature, print speed (cold paper arriving), pixel density (compensating for wiring I^2R loss) and some other factors.

The SPI port shoves out pixels to the head at 4mbits, while I control five burn pulse outputs, and sequence a stepper through accel and decel, depending on how much data I have left to print.

I ran into an unanticipated problem there, as the M8 was able to print the data much faster than the 1.7 GHz laptop was able to deliver it.  This caused interesting problems until I got the stepper speed throttling handled correctly.  The first cut did smooth accel, then stopped dead when I ran out of data, which sounded much worse in real life, than I expected. The final cut adjusts it's speed depending on how many lines are in the buffer, and wether that quantity is stable, rising, or falling.  Don't think "inches per second", think "Feet per second".
It's fast enough to make you think that the paper must have been pre-printed.

The spooky thing was looking at it blowing printed paper out, knowing that except for the stepper drive chip, the whole thing was running on one chip, with no external ram, buffers, latches, not even a crystal.  Another processor interfaces to the PC, and rasterizes the data, then sends that to my M8, through an 8 bit interface we invented, but even that is on chip in the M8.

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