23 Jan
2017
23 Jan
'17
12:26 a.m.
I have luggable with the famous Keytronics foam kepad rot.
I am searching for the foam (have not found it yet), and on a lark, I tried using a PC
keyboard.
In the PC keyboard, I soldered in a 7805 to take the Compaq 12V to 5V for the PC
keyboard.
Traced the clock and data lines, hooked it all up and it does not work.
The Keytronics (compaq) keyboard either has a different protocol or signals inverted, I
have not got that far with the scope yet to see the difference.
Has anybody found a source for the Keytronics mylar foam pads?
Randy
12:44 a.m.
This is the original Compaq I IBM PC clone, 8088
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Fred Cisin <cisin at
xenosoft.com>
Sent: Sunday, January 22, 2017 9:42 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Attempt at Compaq keybord swap with a PC keyboard (failed)
On Mon, 23 Jan 2017, Randy Dawson wrote:
I have luggable with the famous Keytronics foam kepad
rot.
WHAT model Compaq?
8088? 80286?
8:29 a.m.
Easier to fix the foam. But a tip to replace the keyboard...use the Compaq
keyboard bare by pressing fingers directly on the board, verify that works
that way (it should). Record the signals' wire path, match the replacement
keyboard wiring.
B
On Jan 23, 2017 12:45 AM, "Randy Dawson" <rdawson16 at hotmail.com>
wrote:
This is the original Compaq I IBM PC clone, 8088
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Fred Cisin <
cisin at xenosoft.com>
Sent: Sunday, January 22, 2017 9:42 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Attempt at Compaq keybord swap with a PC keyboard (failed)
On Mon, 23 Jan 2017, Randy Dawson wrote:
I have luggable with the famous Keytronics foam
kepad rot.
WHAT model Compaq?
8088? 80286?
11:53 a.m.
Hi William,
I did use the original kybd to trace out the clock and data, most of the keys work, and I
have good scope shots. I am on it again today, because it sure seems like it should work,
using a PC keyboard.
I did not take scope shots on the first test, thinking it should just work.
Hopefully its just a signal inversion, I cant imagine the protocol is that different.
Each keypress looked like a byte of data, 8 cycles on the clock line with corresponding
bits on data line.
Randy
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of william degnan
<billdegnan at gmail.com>
Sent: Monday, January 23, 2017 5:29 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Attempt at Compaq keybord swap with a PC keyboard (failed)
Easier to fix the foam. But a tip to replace the keyboard...use the Compaq
keyboard bare by pressing fingers directly on the board, verify that works
that way (it should). Record the signals' wire path, match the replacement
keyboard wiring.
B
On Jan 23, 2017 12:45 AM, "Randy Dawson" <rdawson16 at hotmail.com>
wrote:
This is the original Compaq I IBM PC clone, 8088
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Fred Cisin <
cisin at xenosoft.com>
Sent: Sunday, January 22, 2017 9:42 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Attempt at Compaq keybord swap with a PC keyboard (failed)
On Mon, 23 Jan 2017, Randy Dawson wrote:
I have luggable with the famous Keytronics foam
kepad rot.
WHAT model Compaq?
8088? 80286?
12:36 p.m.
Just to be sure -- the PC keyboard you're using is an actual PC/XT
compatible keyboard, not an AT, correct? The PC/XT used a different
protocol and is incompatible with later keyboards...
- Josh
On 1/23/17 8:53 AM, Randy Dawson wrote:
Hi William,
I did use the original kybd to trace out the clock and data, most of the keys work, and I
have good scope shots. I am on it again today, because it sure seems like it should work,
using a PC keyboard.
I did not take scope shots on the first test, thinking it should just work.
Hopefully its just a signal inversion, I cant imagine the protocol is that different.
Each keypress looked like a byte of data, 8 cycles on the clock line with corresponding
bits on data line.
Randy
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of william degnan
<billdegnan at gmail.com>
Sent: Monday, January 23, 2017 5:29 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Attempt at Compaq keybord swap with a PC keyboard (failed)
Easier to fix the foam. But a tip to replace the keyboard...use the Compaq
keyboard bare by pressing fingers directly on the board, verify that works
that way (it should). Record the signals' wire path, match the replacement
keyboard wiring.
B
On Jan 23, 2017 12:45 AM, "Randy Dawson" <rdawson16 at hotmail.com>
wrote:
This is the original Compaq I IBM PC clone, 8088
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Fred Cisin <
cisin at xenosoft.com>
Sent: Sunday, January 22, 2017 9:42 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Attempt at Compaq keybord swap with a PC keyboard (failed)
On Mon, 23 Jan 2017, Randy Dawson wrote:
I have luggable with the famous Keytronics foam
kepad rot.
WHAT model Compaq?
8088? 80286?
12:56 p.m.
On 01/23/2017 09:36 AM, Josh Dersch wrote:
Just to be sure -- the PC keyboard you're using is
an actual PC/XT
compatible keyboard, not an AT, correct? The PC/XT used a different
protocol and is incompatible with later keyboards...
That occurred to me also--it seems so obvious that I passed mention of it.
But PC 5150/5160-type keyboards use a very different protocol from 5170
and later keyboards--and they're not interchangeable. Some early
AT-style keyboards can be configured for either mode (e.g. the
Keytroics/Honeywell KB101), but if you're going to use a AT or PS/2
style keyboard with an XT-class machine, you'll need a converter.
--Chuck
2702
days inactive
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days old
6 comments
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