Subject: Re: Good Question?
To: None <>
From: amaya <>
List: port-pmax
Date: 02/17/2001 09:43:20
>Peter C. Wallace skrev:

>>On Fri, 16 Feb 2001 wrote:

>>> I have a DecStation 2100 with a mono framebuffer - hence the good
>>> question...  Could I get a generic radioshack bnc to rca adapter and
>>> just pipe the video through my vcr to my tv?  It is after all just a
>>> mono composite video isn't it?  I just think it would be extremely
>>> cool to be able to switch the channel to my NetBSD DecStation running
>>> my browser, etc, at all.. -Linc.

>>Well, not quite,

>>   Signal level wise you would be alright (RS-343?) but DS2100s video
>>has 864 lines of vertical resolution (56 KHz horizontal) NTSC video has
>>much lower vertical resolution: 525 lines and interlaced (15 KHz
>>horizontal, alternate 262.5 line frames @ 60 Hz)

>>Also might consider that the video bandwith of your TV = ~5 Mhz but the
>>video coming out of the DS2100 is 70 Mhz...

>This sounds interesting. Any more exact specs on the 2100 mono output?
>I suppose this is the same as on the 3100? What is the vertical scan

I just know I looked up the specs of the VR262 years ago. The DS2100 and
3100 are identical in all respects other than CPU speed.

The VR262 is the same as almost all early DEC monitors:
VR150,VR160,VR260,VR262 (mono, composite sync. I was about to say sync on
green...) and VR160,VR290,VR299 (color, sync on green)

They are all designed for 1024x864 resolution at 60 Hz refresh. They are
all fixed frequency monitors with a 56 Khz horizontal rate.

These are the monitors that work with DS2100, DS3100, PMAG-B, VS3100 with
on card mono or GPX color, VCB01, VCB02 etc etc

Not sure about the earlier VS100 monitor - it looks like a VR260 but it
may have different video.

I have often wondered if you could get away with changing the 69 MHz xtal
in a DS3100, VS3100 or GPX card to about 80 Mhz to get a decent (non
headache generating) vertical refresh rate, using a multisync monitor.


>En ligne avec Thor 2.6.

>We have support for the PMAGC-B's on pmax right? That is a PixelVision
>card right? I see Bt 463, that chip looks bigger than the 21164! Just
>at it makes me want to write an Xserver!

>   Chris Tribo, NetBSD/pmax