[Coco] The early days of Hacking and Coding a CoCo Was: Here's a CoCo 1 ...

Steve 6809er at srbsoftware.com
Sat Jan 18 14:51:06 EST 2014


Well, I already hacked my own professional  keyboard for the CoCo, so 
using the Terminal's keyboard was unnecessary.  Besides, trying to read 
input via the serial input on the back of the CoCo is a real pain.

I also created a new keyboard driver for the CoCo that used the 60 Hz 
IRQ to read the keyboard. (Like OS-9 and CoCo 3) Not only the did this 
speed up assemble time by having the keyboard read only done 60 times a 
second, this controlled reading automatically removes keyboard bounce.  
This was technology behind my TRS-80 Model I/III Keyboard debounce that 
also made it feel more snappy.

This driver for my EDTASM had a number of nice features like...

128 byte FIFO key pressed FIFO buffer.  Yes, a bit over kill.  But I 
could type in commands for the computer was busy (like file saving) and 
run once done.

A fast Keyboard for a fast typist.  (When coding, I type at 100+ words 
per minute.)

Auto repeat tuned to my liking.


The EDTASM reads the keyboard after line assembled and spends most of 
the time doing just that.  The standard Keyboard driver is very slow 
since it would take the time to read every keyboard row and add debounce 
time delay.  Because my driver only needs to see if there was anything 
into the buffer by checking the two buffer pointer are a match, it's 
much faster.  Also, there are no debounce delays to slow down the 
assemble performance.

In those early days of the CoCo, there was a lot of hacking and coding 
to make the CoCo useful to us software developers.

Steve

On 1/18/2014 10:16 AM, Arthur Flexser wrote:
> I suppose then that you would have also had to modify Edtasm's keyboard
> input routine to accept input from the terminal, so as to be able to use
> the terminal's keyboard with its cursor control capabilities.
>
> Art
>




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