[comp.sys.amiga.hardware] Connecting an Amiga to a TTL Monochrome monitor

Bill.Frandsen@samba.acs.unc.edu (BBS Account) (08/15/90)

Is there a special cable available to connect the Amiga to a TTL monochrome
monitor?  (specifically, one with a 640x800 resolution?)

Has anyone accomplished this?  If so, how well does it work (i.e. are the
characters as readable as they are on a 1950 in the same mode?, How about
interlace flicker?)

Now, I'm not referring to the mono video output jack on the back of the 
A500/2000/3000 series that is composite, meant for a luminance/composite
input on a VCR/TV.

It would have to be off certain pins on the video port, all I need is a good
clean B+W display.  Which pins are used?  I can build a cable quickly also.

At this time, I do not know the scanning frequency of the monitor, but it
appears to be compatible with an IBM graphics card.

Any help appreciated.  E-Mail address: Bill.Frandsen@bbs.acs.unc.edu

soh@pegasus.trl.oz.au (kam hung soh) (08/16/90)

I'd connected my old A1000 to a CGA-type TTL monitor.  The picture was
refreshingly
sharp in 640 x 256 (I had a PAL A1000) and almost usable in interlace
mode.  Them old
monitors have long persistence phosphor screens!  Unfortunately, the
monitor did not
display all colours (due to the digital input).

To do this, I had to invert the signals of the digital Red, Green and
Blue outputs
from the A1000 with a NOT chip.  Buy a chip prototype board & a chip
socket if you
don't want to burn the chip with your soldering iron.

---
Soh, Kam Hung      email: h.soh@trl.oz.au     tel: +61 03 541 6403 
Telecom Research Laboratories, P.O. Box 249, Clayton, Victoria 3168, Australia 

soh@shiva.trl.oz (kam hung soh) (08/17/90)

soh@pegasus.trl.oz.au (kam hung soh) writes:

>I'd connected my old A1000 to a CGA-type TTL monitor.  The picture was
>refreshingly
>sharp in 640 x 256 (I had a PAL A1000) and almost usable in interlace
>mode.  Them old
>monitors have long persistence phosphor screens!  Unfortunately, the
>monitor did not
>display all colours (due to the digital input).

>To do this, I had to invert the signals of the digital Red, Green and
                                                        ^^^  ^^^^^
>Blue outputs
 ^^^^

AAARGH!  I meant Hsync* and Vsync* outputs!  This should teach me
not to write late in the evening!


Soh, Kam Hung      email: h.soh@trl.oz.au     tel: +61 03 541 6403 
Telecom Research Laboratories, P.O. Box 249, Clayton, Victoria 3168, Australia 

trefz@ohstpy.mps.ohio-state.edu (08/17/90)

In article <816@beguine.UUCP>, Bill.Frandsen@samba.acs.unc.edu (BBS Account) writes:
> Is there a special cable available to connect the Amiga to a TTL monochrome
> monitor?  (specifically, one with a 640x800 resolution?)
> 
> Has anyone accomplished this?  If so, how well does it work (i.e. are the
> characters as readable as they are on a 1950 in the same mode?, How about
> interlace flicker?)
> 
> Now, I'm not referring to the mono video output jack on the back of the 
> A500/2000/3000 series that is composite, meant for a luminance/composite
> input on a VCR/TV.
> 
> It would have to be off certain pins on the video port, all I need is a good
> clean B+W display.  Which pins are used?  I can build a cable quickly also.
> 
> At this time, I do not know the scanning frequency of the monitor, but it
> appears to be compatible with an IBM graphics card.
> 
> Any help appreciated.  E-Mail address: Bill.Frandsen@bbs.acs.unc.edu

We have connected an Amiga 1000 to a RCA TTL monitor and it worked just fine.
The highest mode was 640 by 400.  This monitor was basicly an EGA monitor.

The cables can if you only want to use the TTL monitor, if you want to use
your Amiga monitor it is more complicated.  Find the pin outs in the manual
for the video port.  You will need a 23DB connector, 75 ohm cable and either
BNC or RCA connector to the monitor.  Connect the 75 ohm calbe to the digital
red, green, blue and composite out.  These four are needed for the monitor.
You might also need a box or cover to house the connection depending on the 
number and physical restraints. 

I hope this helps.

Kelvin Trefz
Ohio State University