18 Mar
2005
18 Mar
'05
2:32 p.m.
I have two IBM Model 5150s (one original rev, and a rev b). I think I've
explored every single inch of the hardware except for light pens -- I would
really like to experiment with one and write some software that interfaces with
one. Does anyone know:
1. What light pens were available and for which PCs? (I also own Tandy 1000s,
and they have "light pen" ports too)
2. Does anyone have any light pens for sale or trade?
I've already tried googling and searching usenet -- the only references I can
find are companies selling light pens for modern machines, and tech info that
states the obvious (ie. "The IBM PC supported a light pen"... yeah, thanks :-)
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
18 Mar
18 Mar
4:08 p.m.
I have two IBM Model 5150s (one original rev, and a rev b). I think I've
explored every single inch of the hardware except for light pens -- I would
really like to experiment with one and write some software that interfaces with
one. Does anyone know:
1. What light pens were available and for which PCs? (I also own Tandy 1000s,
and they have "light pen" ports too)
I can tell you that although the MDA card has a light pen connector, the
light pen certainly doesn't work on the 5151 monitor (far too long a
persistance). It does work on most CGA monitors
As regards machines that could take light pens. The Sirius could (or at
least there's a light pin input on the user port header). There's a light
pen signal on the analogue port of the BBC micro (I have the Torch
lightpen for the Beeb, it's not exactly simple!). The FTS88 could take
one as an option too (there's a header on the diagnostic LED board.
Obviously the GT40 does. As does the Vectrex. And I think the Atari 400,
800, etc. The Gemini has a lightpen socket (which happens to be the same
pinout as the connector between the Torch lightpen and its interfae box,
hmmm). The HH Tiger has a lightpen connector
2. Does anyone have any light pens for sale or trade?
No, but it's not hard to make one if you don't require high resolution.
There was at least one design in 80-micro for the Tandy 1000. There were
plenty of designs for the Beeb (most of them use the Honeywell 'Sweet
Spot' devices). Thoese were not as good as the Torch one I mentioned, but
they do work.
-tony
4:47 p.m.
Tony wrote:
I can tell you that although the MDA card has a light
pen connector, the
light pen certainly doesn't work on the 5151 monitor (far too long a
persistance).
Long persistence phospor doesn't preclude the use of a light pen, it
just introduces some limitations on the usage model. The DEC Type 30
and 340 displays as used on the PDP-1 through PDP-10 use a P7 phosphor
which has very high persistence, yet light pens were commonly used with
them.
Eric
6:21 p.m.
On Fri, 18 Mar 2005, Eric Smith wrote:
Tony wrote:
You can cheat with P7 and other double layer phosphors by using a blue filter
as they have a medium or short persistance blue phosphor and a very long
persistance yellow or orange phosphor.
Peter Wallace
I can tell you that although the MDA card has a
light pen connector, the
light pen certainly doesn't work on the 5151 monitor (far too long a
persistance).
Long persistence phospor doesn't preclude the use of a light pen, it
just introduces some limitations on the usage model. The DEC Type 30
and 340 displays as used on the PDP-1 through PDP-10 use a P7 phosphor
which has very high persistence, yet light pens were commonly used with
them.
Eric
10:01 p.m.
Peter C. Wallace wrote:
Okay, now my age and lack of experience is going to show: Can someone explain
to me exactly *how* a light pen works? What is the feedback mechanism if
drawing on, say, a completely black screen? How does the computer get
coordinates for where the pen is touching?
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
Long
persistence phospor doesn't preclude the use of a light pen, it
just introduces some limitations on the usage model. The DEC Type 30
and 340 displays as used on the PDP-1 through PDP-10 use a P7 phosphor
which has very high persistence, yet light pens were commonly used with
them.
You can cheat with P7 and other double layer phosphors by using a blue
filter as they have a medium or short persistance blue phosphor and a
very long persistance yellow or orange phosphor. 
10:13 p.m.
Okay, now my age and lack of experience is going to
show: Can someone
explain
to me exactly *how* a light pen works? What is the feedback mechanism if
drawing on, say, a completely black screen? How does the computer get
coordinates for where the pen is touching?
I can tell you how the C64 does it, and I'm sure the principle is broadly
applicable.
The VIC-II knows at any given point in time which pixel coordinate the
raster beam is currently at. Within the light pen is a sensor which can
pick up the presence of the beam. The screen is being updated 60 times
per second (NTSC), so unless you get the pen off within that 1/60th of a
second, at some point the raster beam will be within view of the light
pen's sensor. When this happens, a triggering signal is sent to the VIC-II,
which latches the current X/Y position of the beam (and therefore the pen)
into its registers. Once read, the registers reset for another read. Since
this all happens in literally a jiffy or two, there is a lot of jitter and
so the C64 PRG recommends sampling and averaging over a few frames before
using the generated coordinates.
There can be additional switches present for more functions. The Inkwell
Systems 170C that I use with my C128 has a simple single switch in the pen
nib which is triggered when depressed, but the pen location can still be
tracked with the pen held sufficiently close to the screen to see the beam,
even without the switch activated.
--
---------------------------------- personal: http://www.armory.com/~spectre/ --
Cameron Kaiser, Floodgap Systems Ltd * So. Calif., USA * ckaiser at floodgap.com
-- Whatever it is, I'm against it. -- Groucho Marx ----------------------------
10:53 p.m.
New subject: ISA Connectors
Can you still buy the 18x2 pin edgeboard that makes an 8 bit ISA slot into a
16 bit one?
I was toying with the idea of expanding my Amiga 2000 (with 286 bridgeboard)
from 2x16 and 2x8bit to 4x16bit ISA slots and
installing a SCSI card, video
card, network card, and something else. The 2000 has
the pinholes for the
connector so installing the edgeboard should not be that big of a deal.
Looking through my old 486 motherboards I noticed that they 16 bit slots are
all 1 piece, so desoldering one of them wont work.
Any ideas? has anybody else bothered to try this?
11:18 p.m.
New subject: ISA Connectors
Can you still buy the 18x2 pin edgeboard that makes an
8 bit ISA slot
into a 16 bit one?
Looking through my old 486 motherboards I noticed that
they 16 bit
slots are all 1 piece, so desoldering one of them wont work.
But mightn't desoldering one and cutting off all but the appropriate
piece? A dremel or a hacksaw should do fine.
I realize it wouldn't be as nice as getting the proepr connector, but
I'd expect it to _work_....
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
11:59 p.m.
New subject: ISA Connectors
From: "Teo Zenios" <teoz at neo.rr.com>
Can you still buy the 18x2 pin edgeboard that makes an
8 bit ISA slot into
a
16 bit one?
I have a small backplane with 4x 16bit ISA slots and 1 8 bit.
The 16 bit slots physically consists of the normal 8 bit plus a separate
edgeboard for the last 8 bits.
If you cant find the parts locally, you can mail me, and have the backplane
for the price of the postage
Nico
19 Mar
19 Mar
12:04 a.m.
New subject: ISA Connectors
Teo Zenios wrote:
Can you still buy the 18x2 pin edgeboard that makes an
8 bit ISA slot into a
16 bit one?
I was toying with the idea of expanding my Amiga 2000 (with 286 bridgeboard)
from 2x16 and 2x8bit to 4x16bit ISA slots and installing a SCSI card, video
card, network card, and something else. The 2000 has the pinholes for the
connector so installing the edgeboard should not be that big of a deal.
Looking through my old 486 motherboards I noticed that they 16 bit slots are
all 1 piece, so desoldering one of them wont work.
Any ideas? has anybody else bothered to try this?
Yes, desolder the whole edge connector (I used a hot air paint
stripper), and cut the bit you want off with a sharp hacksaw.
Gordon.
8:13 a.m.
New subject: ISA Connectors
On Sat, 19 Mar 2005 01:53:24 -0500, Teo Zenios <teoz at neo.rr.com> wrote:
Can you still buy the 18x2 pin edgeboard that makes an
8 bit ISA slot into a
16 bit one?
I was toying with the idea of expanding my Amiga 2000 (with 286 bridgeboard)
from 2x16 and 2x8bit to 4x16bit ISA slots and installing a SCSI card, video
card, network card, and something else. The 2000 has the pinholes for the
There are 8 bit SCSI card (I once sold my two 8 bit SCSI card for $5),
8 bit video card and 8 bit ethernet card.
vax , 9000
connector so installing the edgeboard should not be
that big of a deal.
Looking through my old 486 motherboards I noticed that they 16 bit slots are
all 1 piece, so desoldering one of them wont work.
Any ideas? has anybody else bothered to try this?
10:43 a.m.
New subject: ISA Connectors
At 10:53 PM 3/18/2005, you wrote:
Can you still buy the 18x2 pin edgeboard that makes an
8 bit ISA slot into a
16 bit one?
-Snip-
Looking through my old 486 motherboards I noticed that they 16 bit slots are
all 1 piece, so desoldering one of them wont work.
Any ideas? has anybody else bothered to try this?
one word, Xacto saw :)
4:11 p.m.
New subject: ISA Connectors
Can you still buy the 18x2 pin edgeboard that makes an 8 bit ISA slot into a
16 bit one?
Isn't it just a standard 0/1" pitch edge connector? It shouldn't be hard
to get.
I was toying with the idea of expanding my Amiga 2000 (with 286 bridgeboard)
from 2x16 and 2x8bit to 4x16bit ISA slots and installing a SCSI card, video
card, network card, and something else. The 2000 has the pinholes for the
connector so installing the edgeboard should not be that big of a deal.
Looking through my old 486 motherboards I noticed that they 16 bit slots are
all 1 piece, so desoldering one of them wont work.
IIRC, there's sigificant space between the 2 parts of the connector, so
it should be possible to cut your desoldered connector apart and use only
the '16 bit' part. Or can't you desolder the '8 bit' connectr from the
Amiga and remplace the lot with one of the connectors from the old
motherboard?
-tony
20 Mar
20 Mar
12:31 a.m.
New subject: ISA Connectors
----- Original Message -----
From: "Tony Duell" <ard at p850ug1.demon.co.uk>
To: <cctalk at classiccmp.org>
Sent: Saturday, March 19, 2005 7:11 PM
Subject: Re: ISA Connectors
bridgeboard)
I ended up just cutting the '16 bit' part away from the connector and
installed them in the Amiga (I just used a dremel tool to cut half way into
the connector and made a clean snap).
Since I was in there I did the lithium battery hack so my RTC works again.
Now to see about getting the cards installed and working.
>
> Can you still buy the 18x2 pin edgeboard that makes an 8 bit ISA slot
into a
16 bit one?
Isn't it just a standard 0/1" pitch edge connector? It shouldn't be hard
to get.
>
> I was toying with the idea of expanding my Amiga 2000 (with 286 > from 2x16 and 2x8bit to 4x16bit ISA slots and
installing a SCSI card,
video
> card, network card, and something else. The 2000
has the pinholes for
the
> connector so installing the edgeboard should not
be that big of a deal.
> Looking through my old 486 motherboards I noticed that they 16 bit slots
are
all 1 piece,
so desoldering one of them wont work.
IIRC, there's sigificant space between the 2 parts of the connector, so
it should be possible to cut your desoldered connector apart and use only
the '16 bit' part. Or can't you desolder the '8 bit' connectr from
the
Amiga and remplace the lot with one of the connectors from the old
motherboard?
-tony
19 Mar
19 Mar
9:10 a.m.
Cameron Kaiser wrote:
The VIC-II knows at any given point in time which
pixel coordinate the
raster beam is currently at. Within the light pen is a sensor which can
pick up the presence of the beam.
Does that mean the screen must be non-black for a light pen to work?
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
10:07 a.m.
The VIC-II
knows at any given point in time which pixel coordinate the
raster beam is currently at. Within the light pen is a sensor which can
pick up the presence of the beam.
Does that mean the screen must be non-black for a light pen to work? 
12:39 a.m.
On Sat, 19 Mar 2005 00:01:31 -0600, Jim Leonard <trixter at oldskool.org> wrote:
Okay, now my age and lack of experience is going to
show: Can someone explain
to me exactly *how* a light pen works? What is the feedback mechanism if
drawing on, say, a completely black screen? How does the computer get
coordinates for where the pen is touching?
On the machines I'm familiar with (VLSI video chip like a 6545 or C=
VIC-II), the video chip has a light pen input which looks for a pulse
from a phototransistor which may or may not have a
press-to-the-screen-to-read or a squeeze switch on the pen body (to
keep it from firing when it's not meant to). When the chip sees the
pulse, it latches its internal row/column counters to a register that
can be read after the fact by user software. Some chips (like the
VIC-II) can generate an IRQ when that occurs (the initial version of
the VIC-II chip, on the C= proto run had a flaw that when they warmed
up, they would generate spurious IRQs and hose the machine).
The only requirement is that the beam produce a bright enough flash to
cause the phototransistor to fire deterministically. From memory,
that typically required the application to put something visible to
humans as well on the screen. I've seen check boxes, etc., when used
to capture simple user input (YES/NO...) I do not know if it's
possible to have a dark area of the screen fire the phototransistor or
not.
-ethan
8:19 a.m.
On Sat, 19 Mar 2005 00:01:31 -0600, Jim Leonard
<trixter at oldskool.org> wrote:
It must be able to somehow. I have used a light pen on a Commodore 64 with a
Graphics Program called Picasso's Revenge and have drawn on the screen with
it even on a completely black background. Not sure how it does it though.
Greg
Okay, now my age and lack of experience is going
to show: Can
someone explain
to me exactly *how* a light pen works? What is
the feedback
mechanism if
drawing on, say, a completely black screen? How
does the computer get
coordinates for where the pen is touching?
On the machines I'm familiar with (VLSI video chip like a 6545 or C=
VIC-II), the video chip has a light pen input which looks for a pulse
from a phototransistor which may or may not have a
press-to-the-screen-to-read or a squeeze switch on the pen body (to
keep it from firing when it's not meant to). When the chip sees the
pulse, it latches its internal row/column counters to a register that
can be read after the fact by user software. Some chips (like the
VIC-II) can generate an IRQ when that occurs (the initial version of
the VIC-II chip, on the C= proto run had a flaw that when they warmed
up, they would generate spurious IRQs and hose the machine).
The only requirement is that the beam produce a bright enough flash to
cause the phototransistor to fire deterministically. From memory,
that typically required the application to put something visible to
humans as well on the screen. I've seen check boxes, etc., when used
to capture simple user input (YES/NO...) I do not know if it's
possible to have a dark area of the screen fire the phototransistor or
not.
-ethan
>> FREE spam killer: http://eliminatespam.com *
FREE PopUp Buster+:
http://popupbuster.net
4:08 p.m.
Okay, now my age and lack of experience is going to
show: Can someone explain
to me exactly *how* a light pen works? What is the feedback mechanism if
A light pen is beaically a small light detector (normally a
phototransistor) that detects the ligth from the screen. Since the image
on the screen is scanned (either as a raster, or as vectors), you get a
pulse from the light pne output as the part of the image that the light
pen is aimed at is being refreshed.
Typcially, on raster scan systems (like almsot all microcomputers), the
CRT controller takes the light pen signal and uses it to latch the
current video RAM address, or the X/Y coordinates, or something like
that. The latched values can then be read out by the processor.
drawing on, say, a completely black screen? How does
the computer get
It can't. Period. Any comptuer/light pen that claims to is doing one of 2
things. Either displaying, say, a 3*3 array of pixels under the light
pen, and the computer moves said pattern to keep the middle pixel under
the light pen (this is how a lot of vector displays did it -- if the
light pen posiition is 'lost' for any reason, it was typical to sweep a
line across the screen, then down the screen, to find it again)
Or more likely, the 'black' screen isn't totally black, but a very dark
grey or something. Dark enough that _you_ don't notice it, but the light
pen does
-tony
2:11 a.m.
On Fri, 18 Mar 2005 16:47:14 -0800 (PST), Eric Smith <eric at brouhaha.com>
wrote:
Tony wrote:
There were some tricks with LP displays. One was to generate "sensitive"
fields with a rather dark background which was set to black for every
second frame. The decay was shorter for very dark areas to start with, and
to make it work with a cheap pen you just halved the refresh frequency.
--
-bv
I can tell you that although the MDA card has a
light pen connector, the
light pen certainly doesn't work on the 5151 monitor (far too long a
persistance).
Long persistence phospor doesn't preclude the use of a light pen, it
just introduces some limitations on the usage model. The DEC Type 30
and 340 displays as used on the PDP-1 through PDP-10 use a P7 phosphor
which has very high persistence, yet light pens were commonly used with
them.
18 Mar
18 Mar
4:49 p.m.
2. Does anyone
have any light pens for sale or trade?
No, but it's not hard to make one if you don't require high resolution.
There was at least one design in 80-micro for the Tandy 1000. There were
plenty of designs for the Beeb (most of them use the Honeywell 'Sweet
Spot' devices). Thoese were not as good as the Torch one I mentioned, but
they do work. 
6:44 p.m.
I have an Honest-to-God Atari made light pen in my hand. It has a DB-9
female connector made to be plugged into an Atari 400, 600, 800, etc. front
panel "I/O port" ( used for more than just "joysticks" ). I would be
willing to part with it for only "half" of a song...
Best regards, Steven C. ( Southern California, USA )
>
> I have two IBM Model 5150s (one original rev, and a rev b). I think
I've
> explored every single inch of the hardware except
for light pens -- I
would
> really like to experiment with one and write some
software that
interfaces with
> one. Does anyone know:
>
> 1. What light pens were available and for which PCs? (I also own Tandy
1000s,
and they have
"light pen" ports too)
I can tell you that although the MDA card has a light pen connector, the
light pen certainly doesn't work on the 5151 monitor (far too long a
persistance). It does work on most CGA monitors
As regards machines that could take light pens. The Sirius could (or at
least there's a light pin input on the user port header). There's a light
pen signal on the analogue port of the BBC micro (I have the Torch
lightpen for the Beeb, it's not exactly simple!). The FTS88 could take
one as an option too (there's a header on the diagnostic LED board.
Obviously the GT40 does. As does the Vectrex. And I think the Atari 400,
800, etc. The Gemini has a lightpen socket (which happens to be the same
pinout as the connector between the Torch lightpen and its interfae box,
hmmm). The HH Tiger has a lightpen connector
2. Does anyone have any light pens for sale or trade?
No, but it's not hard to make one if you don't require high resolution.
There was at least one design in 80-micro for the Tandy 1000. There were
plenty of designs for the Beeb (most of them use the Honeywell 'Sweet
Spot' devices). Thoese were not as good as the Torch one I mentioned, but
they do work.
-tony
8:05 p.m.
I've got a crate of them (cream colored and all black)...
Its finding a boxed, mint condition Lightpen softwae package for the
CX-70 cream colored light pen that is truly worth its weight in gold.
Curt
Steven Canning wrote:
I have an Honest-to-God Atari made light pen in my
hand. It has a DB-9
female connector made to be plugged into an Atari 400, 600, 800, etc. front
panel "I/O port" ( used for more than just "joysticks" ). I would be
willing to part with it for only "half" of a song...
Best regards, Steven C. ( Southern California, USA )
--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.7.3 - Release Date: 3/15/2005
>I have two IBM Model 5150s (one original rev,
and a rev b). I think
>
>
I've
>explored every single inch of the hardware
except for light pens -- I
>
>
would
>really like to experiment with one and write
some software that
>
>
interfaces with
>one. Does anyone know:
>
>1. What light pens were available and for which PCs? (I also own Tandy
>
>
1000s,
and they
have "light pen" ports too)
I can tell you that although the MDA card has a light pen connector, the
light pen certainly doesn't work on the 5151 monitor (far too long a
persistance). It does work on most CGA monitors
As regards machines that could take light pens. The Sirius could (or at
least there's a light pin input on the user port header). There's a light
pen signal on the analogue port of the BBC micro (I have the Torch
lightpen for the Beeb, it's not exactly simple!). The FTS88 could take
one as an option too (there's a header on the diagnostic LED board.
Obviously the GT40 does. As does the Vectrex. And I think the Atari 400,
800, etc. The Gemini has a lightpen socket (which happens to be the same
pinout as the connector between the Torch lightpen and its interfae box,
hmmm). The HH Tiger has a lightpen connector
2. Does anyone have any light pens for sale or
trade?
No, but it's not hard to make one if you don't require high resolution.
There was at least one design in 80-micro for the Tandy 1000. There were
plenty of designs for the Beeb (most of them use the Honeywell 'Sweet
Spot' devices). Thoese were not as good as the Torch one I mentioned, but
they do work.
-tony
8:57 p.m.
I have two IBM
Model 5150s (one original rev, and a rev b). I
think I've
explored every single inch of the hardware except
for light
pens -- I would
really like to experiment with one and write some
software that
interfaces with
one. Does anyone know:
1. What light pens were available and for which PCs? (I also
own Tandy 1000s,
and they have "light pen" ports too)
I can tell you that although the MDA card has a light pen connector, the
light pen certainly doesn't work on the 5151 monitor (far too long a
persistance). It does work on most CGA monitors
As regards machines that could take light pens. The Sirius could (or at
least there's a light pin input on the user port header). There's a light
pen signal on the analogue port of the BBC micro (I have the Torch
lightpen for the Beeb, it's not exactly simple!). The FTS88 could take
one as an option too (there's a header on the diagnostic LED board.
Obviously the GT40 does. As does the Vectrex. And I think the Atari 400,
800, etc. The Gemini has a lightpen socket (which happens to be the same
pinout as the connector between the Torch lightpen and its interfae box,
hmmm). The HH Tiger has a lightpen connector
2. Does anyone have any light pens for sale or trade?
No, but it's not hard to make one if you don't require high resolution.
There was at least one design in 80-micro for the Tandy 1000. There were
plenty of designs for the Beeb (most of them use the Honeywell 'Sweet
Spot' devices). Thoese were not as good as the Torch one I mentioned, but
they do work.
-tony
>> FREE spam killer: http://eliminatespam.com *
FREE PopUp Buster+:
http://popupbuster.net
19 Mar
19 Mar
6:58 a.m.
Speaking of light pens, I would love to find a light pen for my Imlac. Here
is the data sheet that I have for the one which I believe was used at the
time:
http://ubanproductions.com/ImlacDocs/lightpendata.pdf
--tom
7218
days inactive
7220
days old
24 comments
18 participants
participants (18)
-
ard＠p850ug1.demon.co.uk -
bv＠norbionics.com -
cannings＠earthlink.net -
curt＠atarimuseum.com -
eric＠brouhaha.com -
ethan.dicks＠gmail.com -
geoffr＠zipcon.net -
gmanuel＠gmconsulting.net -
gordon＠gjcp.net -
mouse＠Rodents.Montreal.QC.CA -
nico＠FARUMDATA.DK -
pcw＠mesanet.com -
spectre＠floodgap.com -
teoz＠neo.rr.com -
trixter＠oldskool.org -
uban＠ubanproductions.com -
vax9000＠gmail.com -
vrs＠msn.com