26 Jul
2006
26 Jul
'06
3:54 a.m.
Looking for thoughts on which machines used parallel ASCII keyboards...
I've got a couple of working machines here that used such a keyboard based
around the AY-3-4592 chip, but only one keyboard to go between them.
The interface between the keyboard and system is just 8 data lines and a
strobe though, all at TTL, so presumably any old keyboard that outputs ASCII
data could be made to work.
Ideally I'd like to find a real basket-case of a system that could provide me
with a donor keyboard. I'm not 100% happy with that, but providing the rest
doesn't go in the bin (such that it might be useful to someone at a later
date) and it's not something that's ultra-rare, it seems a reasonable thing to
do in order to complete an otherwise-pristine system.
Knowing which systems to look out for would be a start. Nascom, maybe? I think
RML 380Z's are probably parallel ASCII too, but their keyboards are already
rare as hen's teeth so I wouldn't be happy with that...
cheers
Jules
--
(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination.
26 Jul
26 Jul
5:39 a.m.
Looking for thoughts on which machines used parallel
ASCII keyboards...
Many (perhaps most) older equipment with an integrated keyboard (ie: not
on a cable) used parallel keyboards - also any with an external keyboard on
a ribbon cable are likely parallel.
I've got a couple of working machines here that
used such a keyboard based
around the AY-3-4592 chip, but only one keyboard to go between them.
The interface between the keyboard and system is just 8 data lines and a
strobe though, all at TTL, so presumably any old keyboard that outputs ASCII
data could be made to work.
Ideally I'd like to find a real basket-case of a system that could provide me
with a donor keyboard. I'm not 100% happy with that, but providing the rest
doesn't go in the bin (such that it might be useful to someone at a later
date) and it's not something that's ultra-rare, it seems a reasonable thing to
do in order to complete an otherwise-pristine system.
Knowing which systems to look out for would be a start. Nascom, maybe? I think
RML 380Z's are probably parallel ASCII too, but their keyboards are already
rare as hen's teeth so I wouldn't be happy with that...
It would be dead simple to make an adapter to convert a standard PC serial keyboard
into an ASCII/strobe parallel interface - you get the added benefits of having lots of
extra keys, and the ability to assign whatever codes you like to them.
You could do it all easily with a single 8051 microcontroller - or if you can't
program
those, an 8031 (8051 with external ROM) would work equally nicely.
Somewhere around here I've got 8051 source code to a little project I did to convert
a PC keyboard to an RS-232 serial interface - It would be very little work to turn that
into a parallel interface.
Regards,
Dave
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html
6:24 a.m.
Dave Dunfield wrote:
Hmm, most of the ones (internal keyboards) I've seen are dumb - the large
number of lines exiting the keyboard are just connected direct to the matrix
and the decoding is done by something on the main CPU board (often the CPU
itself), so not easily transferrable to another system :(
Agreed on the external keyboards with a ribbon cable - but I'm struggling to
think of that many systems which used them to be honest. Most micros had
integrated keyboards, whilst workstation-class stuff was often pretty
proprietary and usually serial. Machines laying somewhere inbetween often seem
to just use a serial port and rely on a separate terminal for their input.
Looking for
thoughts on which machines used parallel ASCII keyboards...
Many (perhaps most) older equipment with an integrated keyboard (ie: not
on a cable) used parallel keyboards - also any with an external keyboard on
a ribbon cable are likely parallel. It would be dead simple to make an adapter to convert
a standard PC serial keyboard
into an ASCII/strobe parallel interface - you get the added benefits of having lots of
extra keys, and the ability to assign whatever codes you like to them.
I was pondering that. More than likely someone on this list has already done
exactly that. Speak now. ;-)
Somewhere around here I've got 8051 source code to
a little project I did to convert
a PC keyboard to an RS-232 serial interface - It would be very little work to turn that
into a parallel interface.
Quite by chance I found such a thing this morning at:
http://www.beyondlogic.org/keyboard/keybrd.htm#1
... the HC705 IC (not a chip I'm familiar with) used may not have enough ports
though if port A needs to be used exclusively by the keyboard (due to high
impedance requirements) and port B is only 8 bits and tied up with the ASCII
interface (plus the strobe line to the machine needs to go somewhere)
I'm sure it'd be dead easy for someone who knows about programming PICs and
the like - as I say, I'm sure someone on here's done it even :-)
cheers
Jules
--
(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination.
7:18 a.m.
Many (perhaps
most) older equipment with an integrated keyboard (ie: not
on a cable) used parallel keyboards - also any with an external keyboard on
a ribbon cable are likely parallel.
Hmm, most of the ones (internal keyboards) I've seen are dumb - the large
number of lines exiting the keyboard are just connected direct to the matrix
and the decoding is done by something on the main CPU board (often the CPU
itself), so not easily transferrable to another system :( Agreed on the external keyboards with a ribbon cable -
but I'm struggling to
think of that many systems which used them to be honest. Most micros had
integrated keyboards, whilst workstation-class stuff was often pretty
proprietary and usually serial. Machines laying somewhere inbetween often seem
to just use a serial port and rely on a separate terminal for their input.
I've got some old Volker Craig terminals with parallel keyboards on ribbon cables.
I'm know I've seen many others over the years ...
It would be
dead simple to make an adapter to convert a standard PC serial keyboard
into an ASCII/strobe parallel interface - you get the added benefits of having lots of
extra keys, and the ability to assign whatever codes you like to them.
I was pondering that. More than likely someone on this list has already done
exactly that. Speak now. ;-)
Somewhere around here I've got 8051 source
code to a little project I did to convert
a PC keyboard to an RS-232 serial interface - It would be very little work to turn that
into a parallel interface.
Quite by chance I found such a thing this morning at:
http://www.beyondlogic.org/keyboard/keybrd.htm#1
... the HC705 IC (not a chip I'm familiar with) used may not have enough ports
though if port A needs to be used exclusively by the keyboard (due to high
impedance requirements) and port B is only 8 bits and tied up with the ASCII
interface (plus the strobe line to the machine needs to go somewhere)
I'm sure it'd be dead easy for someone who knows about programming PICs and
the like - as I say, I'm sure someone on here's done it even :-) 
7:31 a.m.
I produced a board a while back that takes a PC keyboard and has
parallel output, in a number of formats. One of the members on this
list has two of them, and seemed quite pleased. I had intended to
productize it, but never got around to it.
A few of it's features are that it has is that PF keys are
programmable, any keyboard key can be mapped to any keycode, /RESET
output, several built-in keymaps (Apple II, SOL, Otrona, etc), serial
port (PS/2 keyboard can be mapped to serial port, serial port is used
for configuration also), keyboard LEDs track caps/numlock/scroll lock
state, key data and strobe polarity programmable, all through-hole,
readily available parts.
Here's a picture of the finished board:
http://tinymicros.com/gallery/keymapper/dscn1565
Since this was intended to be productized, I've never released the
source code. However, if there's interest in a device like this, I
would be willing to release it to anyone who bought a board with the
agreement that the source would not be redistributed, nor used in any
derivative products. I guess that's basically like a hobbyist license.
Currently, I have no boards, as I only made 3 prototypes of the
final version. If there's enough interest in raw boards, I could turn a
batch. I'd have to do a little research to get the final price per
board, but I'm *guessing* it would be less than $10/ea.
--jc
Dave Dunfield wrote:
Agreed on the "all in one" boards, I was thinking specifically about older
non-
comsumer equipment which often has a separate parallel keyboard inside.
Many of the "all in one" boards also have a keyboard decoder and basically
contain a complete parallel keyboard (but it would be tough to get at) - a lot
of the cheaper stuff does keyboard scanning via the CPU.
HC705 is a single-chip microcontroller. This project is very similar to the
one I did, except that I used an 8051, and mine worked on raw scancodes
(both ways, so that you could control the keyboard over the serial port as
well using the standard keyboard control codes).
For a parallel keyboard interface, you would translate the scancode to
ASCII. Most likely you would also implement Caps-Lock and Num-Lock
locally on the controller, setting flags to modify subsequent output and
sending the code to control the keyboard LEDs.
IIRC the existing code is only about 200 bytes, there would be lots of room
left in a 4k 8051 to implement a scan-code -> ASCII translate table and added
functions. To modify the code for a parallel interface, all you would need to do is:
- On the key-down code, check for special keys (CapsLock, NumLock) and
set appropriate flags/Leds, otherwise use the table to convert to ASCII, write it
to the parallel port and assert strobe.
- On key up, deassert strobe.
If you want to implement auto-repeat, just start inital timer on keydown, and
if it expires before key-up, pulse strobe and reset timer to repeat rate.
If you are able to wait a couple of weeks, I could do it for you, I just have
another project I need to get finished first.
Regards,
Dave
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html
Many (perhaps most) older equipment with an integrated
keyboard (ie: not
on a cable) used parallel keyboards - also any with an external keyboard on
a ribbon cable are likely parallel.
Hmm, most of the ones (internal keyboards) I've seen are dumb - the
large
number of lines exiting the keyboard are just connected direct to the matrix
and the decoding is done by something on the main CPU board (often the CPU
itself), so not easily transferrable to another system :(
Agreed on the external keyboards with a ribbon
cable - but I'm struggling to
think of that many systems which used them to be honest. Most micros had
integrated keyboards, whilst workstation-class stuff was often pretty
proprietary and usually serial. Machines laying somewhere inbetween often seem
to just use a serial port and rely on a separate terminal for their input.
I've got some old Volker Craig terminals with parallel keyboards on ribbon cables.
I'm know I've seen many others over the years ...
It would
be dead simple to make an adapter to convert a standard PC serial keyboard
into an ASCII/strobe parallel interface - you get the added benefits of having lots of
extra keys, and the ability to assign whatever codes you like to them.
I was pondering that. More than likely someone on this list has already
done
exactly that. Speak now. ;-)
Somewhere around here I've got 8051 source
code to a little project I did to convert
a PC keyboard to an RS-232 serial interface - It would be very little work to turn that
into a parallel interface.
Quite by chance I found such a thing this morning at:
http://www.beyondlogic.org/keyboard/keybrd.htm#1
... the HC705 IC (not a chip I'm familiar with) used may not have enough ports
though if port A needs to be used exclusively by the keyboard (due to high
impedance requirements) and port B is only 8 bits and tied up with the ASCII
interface (plus the strobe line to the machine needs to go somewhere)
I'm sure it'd be dead easy for someone who knows about programming PICs and
the like - as I say, I'm sure someone on here's done it even :-)
1:23 p.m.
> It would be dead simple to make an adapter to
convert a standard PC serial keyboard
> into an ASCII/strobe parallel interface - you get the added benefits of having lots
of
> extra keys, and the ability to assign whatever codes you like to them.
On Wed,
26 Jul 2006, Jules Richardson wrote:
I was pondering that. More than likely someone on this
list has already done
exactly that. Speak now. ;-)
I did it with an XT. Read a character and print it to LPT, in a loop.
Dave's mention of building a circuit would certainly be a smaller, more
"elegant" solution.
2:48 p.m.
> > It would be dead simple to make an adapter
to convert a standard PC serial keyboard
> > into an ASCII/strobe parallel interface - you get the added benefits of having
lots of
> > extra keys, and the ability to assign whatever codes you like to them.
:
> I was pondering that. More than likely someone on
this list has already done
> exactly that. Speak now. ;-)
I did it with an XT. Read a character and print it to
LPT, in a loop.
Dave's mention of building a circuit would certainly be a smaller, more
"elegant" solution.
Yeah, but an old PC is cheaper (ie: free), much faster to build (all you need
to make is the LPT->keyboard interface cable), already in a box and better
looking (at least compared to MY that my homebrew creations).
It's not such a bad idea.
Yes, it will draw more power than a itty-bitty dedicated controller, but for
the application we are discussing, it's unlikely to see high duty-cycle use.
You could write the program to run under DOS and autoexec it from a
floppy, no need for hard drive or monitor. Tuck the PC under the bench,
and just turn it on when you need it.
Dave
--
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.classiccmp.org/dunfield/index.html
2:43 p.m.
On 7/27/06, Jules Richardson <julesrichardsonuk at yahoo.co.uk> wrote:
Dave Dunfield wrote:
Hmm, most of the ones (internal keyboards) I've seen are dumb - the large
number of lines exiting the keyboard are just connected direct to the matrix
and the decoding is done by something on the main CPU board (often the CPU
itself), so not easily transferrable to another system :(
That was certainly the case for Commodore equipment (PET, VIC-20, C-64...)
Looking
for thoughts on which machines used parallel ASCII keyboards...
Many (perhaps most) older equipment with an integrated keyboard (ie: not
on a cable) used parallel keyboards - also any with an external keyboard on
a ribbon cable are likely parallel. Agreed on the external keyboards with a ribbon cable -
but I'm struggling to
think of that many systems which used them to be honest. Most micros had
integrated keyboards, whilst workstation-class stuff was often pretty
proprietary and usually serial. Machines laying somewhere inbetween often seem
to just use a serial port and rely on a separate terminal for their input.
My recollection is that the mid-1970s were the heyday of ASCII
keyboards (AIM-65 and similar machines). By the early 80s, small
machines tended to have matrix scanned (proprietary) raw keyboards or
some serial interface, as you mention, in both cases for cost.
Quite by chance I found such a thing this morning at:
http://www.beyondlogic.org/keyboard/keybrd.htm#1
... the HC705 IC (not a chip I'm familiar with) used may not have enough ports
though if port A needs to be used exclusively by the keyboard (due to high
impedance requirements) and port B is only 8 bits and tied up with the ASCII
interface (plus the strobe line to the machine needs to go somewhere)
Could that be a Motorola 68HC705?
-ethan
4:33 p.m.
Looking for thoughts on which machines used
parallel ASCII keyboards...
Many (perhaps most) older equipment with an integrated keyboard (ie: not
on a cable) used parallel keyboards - also any with an external keyboard on
a ribbon cable are likely parallel.
> I've got a couple of working machines here that used such a keyboard based
> around the AY-3-4592 chip, but only one keyboard to go between them.
As a real kludge to get things working, how about an old PC laptop, and
link the parallel port of said machine to the keyboard input on your
classic system. The necessary software shouldn't be hard to write.
> Knowing which systems to look out for would be a
start. Nascom, maybe? I think
> RML 380Z's are probably parallel ASCII too, but their keyboards are already
> rare as hen's teeth so I wouldn't be happy with that...
Ditto PERQ 1/1a
It would be dead simple to make an adapter to convert a standard PC serial keyboard
into an ASCII/strobe parallel interface - you get the added benefits of having lots of
extra keys, and the ability to assign whatever codes you like to them.
I was going to suggest something like that. In fact one day I must get
round to designing such and interface.
-tony
27 Jul
27 Jul
5:19 a.m.
Tony Duell schrieb:
I was going to suggest something like that. In fact one day I must get
round to designing such and interface.
This has been already done, and is available on the Net. Look at the
schematics for the Apple I replica at www.applefritter.com;
this contains an ATMEL controller to convert a PC keyboard to the
7bit+strobe required for the Apple I. It is probably just a matter
of changing the translation table in the code to adapt to any encoding.
An ATMEGA8515 is maybe overkill for such a converter, as
it has 2 unused 8 bit ports , but it is a little bit less powerconsuming
as a PC with a parallel port.
--
Holger Veit
Looking for thoughts on which machines used parallel
ASCII keyboards...
It would be dead simple to make an adapter to convert a standard PC serial
keyboard
into an ASCII/strobe parallel interface - you get the added benefits of having lots of
extra keys, and the ability to assign whatever codes you like to them.
6:19 a.m.
This has been already done, and is available on the
Net. Look at the
schematics for the Apple I replica at www.applefritter.com;
this contains an ATMEL controller to convert a PC keyboard to the
7bit+strobe required for the Apple I. It is probably just a matter
of changing the translation table in the code to adapt to any encoding.
An ATMEGA8515 is maybe overkill for such a converter, as
it has 2 unused 8 bit ports , but it is a little bit less powerconsuming
as a PC with a parallel port.
I'm a bit out of time, but this can be easily done with an atmega 2313
(18 pin, 15 I/O ports). Look for BASCOM in www.mcselec.com - this is a easy
way to program that, you just need to capture the PS/2 data and use data
lines and lookup to convert to your 7-bit desired value.
7:17 a.m.
Rumor has it that Holger Veit may have mentioned these words:
This has been already done, and is available on the
Net. Look at the
schematics for the Apple I replica at www.applefritter.com;
this contains an ATMEL controller to convert a PC keyboard to the
7bit+strobe required for the Apple I. It is probably just a matter
of changing the translation table in the code to adapt to any encoding. An
ATMEGA8515 is maybe overkill for such a converter,
For that *exact* use, it may be overkill - but I've been wanting to build
an PS/2 -> CoCo adapter for quite some time out of one of my currently
unused 90S8515's I have collecting dust... The CoCo needs 2 8-bit ports for
the keyboard matrix interface; and you could still have an 8-bit port
configured as a straight ascii backup.
I've wandered around that site for quite a while, and I found the
schematics, but no source code for the 90S8515/ATMEGA8515. Do you know if
it's available, or is it closed-source?
Thanks!
Roger "Merch" Merchberger
--
Roger "Merch" Merchberger -- SysAdmin, Iceberg Computers
zmerch at 30below.com
Hi! I am a .signature virus. Copy me into your .signature to join in!
8:42 a.m.
Roger Merchberger schrieb:
Rumor has it that Holger Veit may have mentioned these
words:
It's well hidden: download the
"Replica 1 Firmware" firmware.zip file at
http://www.applefritter.com/taxonomy/term/229,131 (search path: the
Apple I owners Club page, from there to File Library / Drivers).
--
Holger Veit
This has been already done, and is available on
the Net. Look at the
schematics for the Apple I replica at www.applefritter.com;
this contains an ATMEL controller to convert a PC keyboard to the
7bit+strobe required for the Apple I. It is probably just a matter
of changing the translation table in the code to adapt to any
encoding. An ATMEGA8515 is maybe overkill for such a converter,
For that *exact* use, it may be overkill - but I've been wanting to
build an PS/2 -> CoCo adapter for quite some time out of one of my
currently unused 90S8515's I have collecting dust... The CoCo needs 2
8-bit ports for the keyboard matrix interface; and you could still
have an 8-bit port configured as a straight ascii backup.
I've wandered around that site for quite a while, and I found the
schematics, but no source code for the 90S8515/ATMEGA8515. Do you know
if it's available, or is it closed-source? 
26 Jul
26 Jul
2:53 p.m.
Jules Richardson wrote:
Looking for thoughts on which machines used parallel
ASCII keyboards...
I've got a couple of working machines here that used such a keyboard
based around the AY-3-4592 chip, but only one keyboard to go between them.
I have a spare parallel ASCII keyboard in the loft. Would
that help, if I could get it to you?
--
John Honniball
coredump at gifford.co.uk
6722
days inactive
6723
days old
13 comments
10 participants
participants (10)
-
alexandre-listas＠e-secure.com.br -
ard＠p850ug1.demon.co.uk -
cisin＠xenosoft.com -
coredump＠gifford.co.uk -
dave06a＠dunfield.com -
ethan.dicks＠gmail.com -
holger.veit＠iais.fraunhofer.de -
jcwren＠jcwren.com -
julesrichardsonuk＠yahoo.co.uk -
zmerch-cctalk＠30below.com