27 Jul
2006
27 Jul
'06
12:48 p.m.
(sounds like a stevie wonder song, "r-g-b...and l-c-d..." (ugg, clearly
I've
had too much coffee).
I have an old computer from the '80s and it has a frame buffer with
RGB+S (sync) output on classic BNC connectors.
Back in the day I'd go find a suitable (unbearably heavy) RGB monitor and
4 coax cables and connect the two.
But I find myself without any RBG monitors these days. But I do have a
bunch of new-ish LCD monitors which seem quite happy to sync up to
pretty much anything.
So, can I just (somehow) connect the RBG+S signals to a mondern LCD?
Has anyone tried this?
I haven't even thought about it electrically so this may be thinking out
loud. Most of these lcd monitors seem to have VGA signals. I did once
have a DW13 to RBG/BNC connector. And I think I have a DW13 to VGA
adapter... Is that the right way to go?
I don't know anything about the frame buffer in this thing. I suspect
it's some sort of 640x480x8 device. I can do some digging. (it's a
Symbolics 3630 lisp machine in case you are wondering, a so called
"g-machine", where they put the original 3600 into a small number of
FPGAs).
Any advise appreciated...
-brad
27 Jul
27 Jul
2:05 p.m.
(sounds like a stevie wonder song, "r-g-b...and l-c-d..." (ugg, clearly
I've
had too much coffee).
I have an old computer from the '80s and it has a frame buffer with
RGB+S (sync) output on classic BNC connectors.
Back in the day I'd go find a suitable (unbearably heavy) RGB monitor and
4 coax cables and connect the two.
But I find myself without any RBG monitors these days. But I do have a
bunch of new-ish LCD monitors which seem quite happy to sync up to
pretty much anything.
So, can I just (somehow) connect the RBG+S signals to a mondern LCD?
Has anyone tried this?
I haven't even thought about it electrically so this may be thinking out
loud. Most of these lcd monitors seem to have VGA signals. I did once
have a DW13 to RBG/BNC connector. And I think I have a DW13 to VGA
adapter... Is that the right way to go?
I don't know anything about the frame buffer in this thing. I suspect
it's some sort of 640x480x8 device. I can do some digging. (it's a
Symbolics 3630 lisp machine in case you are wondering, a so called
"g-machine", where they put the original 3600 into a small number of
FPGAs).
Not rgb+s, but I hooked up my ATW800 with Sync-on-Green to my NEC
LCD ... The ATW800 has BNC connectors, and I just hacked a VGA cable
and put connectors on it ....
The result: It has a gorgeous picture, looks great and would be perfetly usable
except for the large white box covering the middle of the screen that you can't
get rid of no-how which says "OUT OF RANGE".
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
1:46 p.m.
On 7/27/2006 at 4:05 PM Dave Dunfield wrote:
Not rgb+s, but I hooked up my ATW800 with Sync-on-Green
to my NEC
LCD ... The ATW800 has BNC connectors, and I just hacked a VGA cable
and put connectors on it ....
The result: It has a gorgeous picture, looks great and would be perfetly
usable except for the large white box covering the middle of the screen
that you
can't get rid of no-how which says "OUT OF
RANGE".
Sounds as if a sync separator would come in handy. There's the
veneered-and-generated LM1881 or you can just set up a couple of one-shots
and some support logic to do the job.
Cheers,
Chuck
29 Jul
29 Jul
4:09 a.m.
On 7/27/2006 at 4:05 PM Dave Dunfield wrote:
Curious as to why a Sync Seperator would be useful - the monitor I was using
does handle sync-on-green, and the picture was nicely stable - I interpreted the
"out of range" message to indicate that the micro in the monitor had decided
that
the sync was not within the frequency specifications of the monitor (although the
monitor itself appeared to be handling it perfectly).
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
Not rgb+s, but I hooked up my ATW800 with
Sync-on-Green to my NEC
LCD ... The ATW800 has BNC connectors, and I just hacked a VGA cable
and put connectors on it ....
The result: It has a gorgeous picture, looks great and would be perfetly
usable except for the large white box covering the middle of the screen
that you
can't get rid of no-how which says "OUT
OF RANGE".
Sounds as if a sync separator would come in handy. There's the
veneered-and-generated LM1881 or you can just set up a couple of one-shots
and some support logic to do the job.
8:29 a.m.
On 7/29/2006 at 6:09 AM Dave Dunfield wrote:
Curious as to why a Sync Seperator would be useful -
the monitor I was
using does handle sync-on-green, and the picture was nicely stable - I
interpreted the "out of range" message to indicate that the micro in the
monitor had
decided that the sync was not within the frequency
specifications of the
monitor
(although the monitor itself appeared to be handling it
perfectly).
It wasn't clear to me that your monitor was handling the SOG signal
correctly. I suspected that perhaps the combined sync might be confusing
it causing to display the "Out of Range" message. Perhaps this isn't the
case and you really do have a signal that really does lie outside the range
of permissable sync frequencies for your monitor.
Just a thought, at any rate.
Cheers,
Chuck
27 Jul
27 Jul
2:24 p.m.
Brad Parker wrote:
(sounds like a stevie wonder song, "r-g-b...and
l-c-d..." (ugg, clearly I've
had too much coffee).
I have an old computer from the '80s and it has a frame buffer with
RGB+S (sync) output on classic BNC connectors.
Couple of things:
1) I expect any modern LCD is going to want analogue colour signals
2) Some LCDs will probably only work with separate H/V sync lines - some will
be good enough to accept composite sync (such as your machine is outputting),
and some will probably work with sync on green too.
I don't think I've ever seen a machine with separate RGB BNC outputs that
presents a digital (TTL or otherwise) signal at the outputs - they've always
been analogue. Doesn't mean to say it can't happen, though.
If you've got a 'scope, put it on one of the outputs of your system and check
the peak voltage. If your LCDs have a VGA connector (as I suspect they have!)
then you can look up VGA signal levels on the 'net and just check that you're
not going to toast the LCD because the voltage at the BNCs is too high.
Other than that though, it probably stands a good chance of working, and you
won't cook anything by trying.
cheers
Jules
--
(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination.
30 Jul
30 Jul
8:10 p.m.
Brad Parker wrote:
I haven't even thought about it electrically so
this may be thinking out
loud. Most of these lcd monitors seem to have VGA signals. I did once
have a DW13 to RBG/BNC connector. And I think I have a DW13 to VGA
adapter... Is that the right way to go?
Any decent scan converter will take the R/G/B/S and convert it to
something else, although "decent" means "expensive" in most cases.
The
Sony DSC-1024 series do this, as do RGB Spectrum units. Both show up on
ebay occaisonally.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Help our electronic games project: http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
A child borne of the home computer wars: http://trixter.wordpress.com/
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brad＠heeltoe.com -
cclist＠sydex.com -
dave06a＠dunfield.com -
julesrichardsonuk＠yahoo.co.uk -
trixter＠oldskool.org