[Coco] Coco 2 Keyboards...

Stephen H. Fischer SFischer1 at Mindspring.com
Fri Apr 24 00:34:29 EDT 2015


Back before the first CoCo there was FLEX09 running on a SYM-1. 

I needed a keyboard so I opened National's databook and found the: 

"The MM57499 serial keyboard- encoder integrated circuit, which scans a 12 by 8 matrix and produces the appropriate ASCII code for each key", found a keyboard that had the keys supported from above and a unattached (Except by the pins from the keys) PC Board. 

So I unsoldered all the keys from the PC board and scraped all the traces off and then wired the keys into the matrix required by the MM57499.

It worked great after I wrote the Key Bounce eliminator code for the key presses the SY6551 saw.
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Two points, 

1) Before building a keyboard from scratch, see if you can find one with the keys supported from above like I did.

2) We really missed the boat in not writing a more reasonable keyboard approach when NitrOS-9 was started. When I needed more command keys for Colorful SLED I wrote a utility that displayed what OS-9 programs saw when keys were pressed. Many ASCII codes were generated by several key combinations, some ASCII codes could not be generated at all and one only produced a code (00) when held down and then produced the (00) code at a fast rate until it was released.
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And a third point, From the Cloud9 new opening page:

"provides all keys that the Color Computer expects in both BASIC and NitrOS-9"

In writing "Colorful Sled" I wanted all 256 ASCII codes and was dismayed that so many were missing.

Do you know that OS-9 will display many more characters than are normally used on the graphics screens? (CoCo 3) 

Fire up Colorful SLED and while holding down CTRL press and hold the "@" key.

Then press "Q" <cr> and then the key codes will be displayed.

A high resolution graphics screen is needed but holding the ALT key down and pressing the "A" key produces a character not normally seen, "B" and up to "Z". (It has been twenty file (25) years so I may not be precisely correct.)

I have a hard copy of what is "normal", "shifted", "ctrl" and "alt" combinations produced.

The OS-9 manual has the alt characters but the keys used I had to paste those onto what was shown.

SHF

(Sorry, too many memories about the poor OS-9 keyboard routine.)
 
----- Original Message ----- 
From: "Zippster" <zippster278 at gmail.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Thursday, April 23, 2015 5:44 PM
Subject: Re: [Coco] Coco 2 Keyboards...


> Making some keyboards with cherry switches would be somewhat expensive, but
> I think I’d do it if I could get proper keycaps for a decent price.
> The keyswitches are expensive enough you’d want good keycaps with the correct
> key symbol, and custom keycaps are expensive enough to kind of kill the idea.
> 
> I suppose someone could possibly 3d print keycap adapters to use original caps.
> 
> That might be doable.
> 
> - Ed
> 
> 
> 
>> On Apr 23, 2015, at 4:55 PM, Al Hartman <alhartman6 at optonline.net> wrote:
>> 
>> Oak appears to be out of the business. To get a company to make the mylar matrices, you'd have to order quite a few.
>> 
>> I think it would be easier to lay out a PCB, and solder in individual Cherry key stations. But, that's pretty expensive.
>> 
>> Unless we can find something surplus to adapt, a Cloud-9 PS/2 adapter is the only game in town right now.
>> 
>> -[ Al ]-
>> 
>> -----Original Message----- From: Josh Harper via Coco
>> 
>> wonder if there is a company that can remake the mylar  id buy several
>> I have a hjl keyboard that when u press ? you get \\ ?



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