mrapple@quack.sac.ca.us (Nick Sayer) (06/14/91)
I've managed to obtain at a rediculously low price a motherboard for the grand old video game "Robotron: 2084". I know it generates analog R, G, and B signals, and separate TTL horizontal and verticle sync outputs. Fine and dandy. Setting aside for the moment concerns about losing definition, is there a way (I know it won't be easy) to convert this signal into an NTSC format? Monochrome will do, by the way. If not, all is not lost. I know that the Apple IIgs monitor is an Analog RGB monitor, but it needs a composite sync signal. My bright idea is to send the TTL H and V sync into the control pins of a pair of CD4066 "digital switch" elements, whose inputs attach to a pair of pots, and outputs connect together and go to the composite sync output. Will this plan work? -- Nick Sayer | Official Scapegoat for the | RIP: Mel Blanc mrapple@quack.sac.ca.us | MC68HC11 Mailing List. | 1908--1989 N6QQQ | To subscribe, send mail to | May he never 209-952-5347 (Telebit) | mc68hc11-request@quack.sac.ca.us | be silenced.
mrapple@quack.sac.ca.us (Nick Sayer) (06/15/91)
Many people have written with the answer to this question, so I thought I'd share it. I (Nick Sayer <mrapple@quack.sac.ca.us>) wrote: <I've managed to obtain at a rediculously low price <a motherboard for the grand old video game "Robotron: 2084". <I know it generates analog R, G, and B signals, and separate TTL <horizontal and verticle sync outputs. Fine and dandy. Setting aside <for the moment concerns about losing definition, is there a way <(I know it won't be easy) to convert this signal into an NTSC <format? Monochrome will do, by the way. <If not, all is not lost. I know that the Apple IIgs monitor is an <Analog RGB monitor, but it needs a composite sync signal. My bright <idea is to send the TTL H and V sync into the control pins of a pair <of CD4066 "digital switch" elements, whose inputs attach to <a pair of pots, and outputs connect together and go to the <composite sync output. Will this plan work? Motorola makes a chip numbered MC1377 that converts Analog RGB to NTSC or PAL. I have written to Motorola to get a data sheet. Without having a data sheet, I'm not sure it's the answer, but it is described as being an Analog RGB to NTSC converter. How much more straightforward can it get? Thanks to all those who replied. I am a happy camper. -- Nick Sayer | Official Scapegoat for the | RIP: Mel Blanc mrapple@quack.sac.ca.us | MC68HC11 Mailing List. | 1908--1989 N6QQQ | To subscribe, send mail to | May he never 209-952-5347 (Telebit) | mc68hc11-request@quack.sac.ca.us | be silenced.
rls@cbnewsc.att.com (richard.l.schieve) (06/18/91)
In article <kWHFvXK@quack.sac.ca.us>, mrapple@quack.sac.ca.us (Nick Sayer) writes: > I've managed to obtain at a rediculously low price > a motherboard for the grand old video game "Robotron: 2084". > I know it generates analog R, G, and B signals, and separate TTL > horizontal and verticle sync outputs. Fine and dandy. Setting aside > for the moment concerns about losing definition, is there a way > (I know it won't be easy) to convert this signal into an NTSC > format? Monochrome will do, by the way. > > If not, all is not lost. I know that the Apple IIgs monitor is an > Analog RGB monitor, but it needs a composite sync signal. My bright > idea is to send the TTL H and V sync into the control pins of a pair > of CD4066 "digital switch" elements, whose inputs attach to > a pair of pots, and outputs connect together and go to the > composite sync output. Will this plan work? > > -- > Nick Sayer | Official Scapegoat for the | RIP: Mel Blanc > mrapple@quack.sac.ca.us | MC68HC11 Mailing List. | 1908--1989 > N6QQQ | To subscribe, send mail to | May he never > 209-952-5347 (Telebit) | mc68hc11-request@quack.sac.ca.us | be silenced. Well, this will be the third time I tried to reply to this. If this is the 3rd time you have seen it, my appologies (sp), but as far as I can tell it is not getting out. First of all, I hope you mean board set not board as Robotron is a four board set, ROM, Input, Sound, and Video/CPU. Second, a composite sync is already available, just normally not used. Check out the schematics that show the connector that has the horizontal/vertical syncs and you will find an unused pin. On the schematic for the Video/CPU board you will find that this is a composite sync output. If you do want to make a composite sync out of seperate horizontal and vertical syncs, this is often done by connecting both syncs to inputs of an exclusive-or gate and the output is used as a composite sync. Sometimes some inversions are needed depending on whether you need active low or active high syncs. I hope this helps, Rick Schieve rls@ihlpb.att.com