View Full Version : Hooking up S100 Video boards to modern LCD's

November 11th, 2008, 10:34 AM
Hi Everybody, I'm new here and have just started to get back into working with (now vintage) S-100 Computer systems as a true hobby. I played around in the 70's and 80's and fortunately stored the 50 or so S100 cards I had. Anyway enough of that.

My first immediate "problem" is seeing if I can get my video cards to output on to a modern LCD display. They are suppose to be multi sync.

Case in point, I really like the SD Systems Video Board. It puts out a separate H Sync, V, Sync and video signal to a CRT. Now it's only 25 lines X 80 characters wide. So the V sync will be low. I measured it at 15.7 kHz.

Before I re-invent the wheel have any of you addressed the problem of using these older video boards with a current LCD display. Are there converter boxes or something?

November 11th, 2008, 10:54 AM
You'll need a "scan doubler" or "line doubler" to bring the scan frequencies in line with modern VGA-compatible LCD monitors. Basically, it does this by scanning each line twice, doubling the horizontal scan rate.

Software Hut used to have a reasonably priced model here (http://www.softhut.com/cgi-bin/test/Web_store/web_store.cgi?page=catalog/hardware/accelerators/apollo_scandoublers.html), but it seems to be in suspension.

November 11th, 2008, 11:00 AM
Thanks for the rapid feedback Chuck. Frustrating to see they are not currently making the "Toastscan"! has anybody else seen something similar or a circuit diagram.

BTW, I meant a Horz Scan rate 15.7 kHz. The V scan is of course 50/60

November 11th, 2008, 11:26 AM
Google around for "Line Doubler", which is what the video crowd calls the things--you might find something appropriate.

AverLogic does make a couple of ICs to do the job, if you're up to rolling your own:


November 11th, 2008, 01:37 PM
Think I found just the thing here:-
At $99.00 It's wort the try. Will let you kno how it works out later (traveling next week).

November 11th, 2008, 02:24 PM
Looks like just the ticket.

A little sobering when you consider that the little box probably has far more memory and a couple of orders of magnitude more computational power than the S-100 box! ;)