Post by thread:Serial Video Display Module

I'm working on an automotive project and I have need of a simple way to output video to a normal NTSC monitor. I've looked at a bunch of solutions and I think I found one that will work. When I researched this problem it came to me that maybe other people could use a self contained module to do the same thing. Remember that none of this is set in concrete and the features listed are only the one's I need. Your needs may be different (if so tell me)... Here's what I came up with; see if it could be useful and send me a note: - Easy to use 3-wire (Enable, SerialData, Clock) serial interface - Software selected NTSC or PAL Video - Composite and Y/C (S-Video) Outputs - Extensive Command Set (23 commands) - Flexible Character Sizing: Up to 12 lines and 12 to 36 columns - 256 predefined characters - Each character is defined in a 12x18 dot matrix - 16 Colors for Foreground or Screen Background - Flashing text on a character-by-character basis - 6 different software selected flash rates - Small board size: 3" x 4.5" - 10-pin header connector for communications - Cursor Control - Power Saving Sleep Mode - Other display features similar to text LCD modules I'm not sure about pricing yet, but I'm fairly sure it won't be over $100. If there is enough interest I may be able to have a few ready by the beginning of next year. More info is available on a web page I put together. Please check out the page and give me some feedback. I want to be sure to include as many important features as possible: http:http://www.flash.net/~thoffman/video.html Thanks!

Hi, I saw the two words 'automotive' and 'video', and I have to comment that in the UK it is illegal to have a video display in view of the driver of a car. I am unsure of the scope of this law (or if it has now been dropped), since recently BMW were selling a top of the range model which had a TV incorporated in the dash. I wonder if the law prohibits specifically a CRT, and you get round it by using an LCD. >I'm working on an automotive project and I have need of a simple way >to output video to a normal NTSC monitor. I've looked at a bunch of >solutions and I think I found one that will work. When I researched >this problem it came to me that maybe other people could use a self >contained module to do the same thing. Remember that none of this is >set in concrete and the features listed are only the one's I need. Why not use a Teletext style video generator. It is all character-based, and gives you 40x24 characters (in the UK with PAL), 8 colours, flash mode and graphics (where each character is a 3x2 pixel block). A chip that does this was used in the BBC Micro (from Acorn Computers), and I think the part number began 'SAA' (I am sure someone has a BBC handbook just to hand. I seem to have omitted to bring mine). Anyway this is my opinion. You are welcome to it... =:^) Andy (the other one)

Andy Errington <spam_OUTa.erringtonTakeThisOuTLANCASTER.AC.UK> > I saw the two words 'automotive' and 'video', and I have to comment that > in the UK it is illegal to have a video display in view of the driver of > a car. Curious. In Australia most taxis now have a display mounted above the instrument panel which gives them information about what jobs are on offer, special messages etc. Many other delivery vehicles have similar systems - all mounted in view of the driver. I don't believe any of them are CRT based, but some of them are quite large flat display panels much like an LCD TV set. -- Clyde Smith-Stubbs | HI-TECH Software, | Voice: +61 7 3300 5011 .....clydeKILLspam@spam@hitech.com.au | P.O. Box 103, Alderley, | Fax: +61 7 3300 5246 http://www.hitech.com.au | QLD, 4051, AUSTRALIA. | BBS: +61 7 3300 5235 --------------------------------------------------------------------------- For info on the World's best C cross compilers for embedded systems, point your WWW browser at http://www.hitech.com.au, or email infoKILLspamhitech.com.au

Andy Errington wrote: > > Hi, > > I saw the two words 'automotive' and 'video', and I have to comment that > in the UK it is illegal to have a video display in view of the driver of > a car. I am unsure of the scope of this law (or if it has now been > dropped), since recently BMW were selling a top of the range model which > had a TV incorporated in the dash. I wonder if the law prohibits > specifically a CRT, and you get round it by using an LCD. > AFAIK, the law is still in place. BMW are careful to switch the TV off when the ignition is on. It is a couple of years since I was working in this area, but the companies I was working with had letters of exemption allowing them to use LCD and CRT displays (for navigation aids and vision enhancement aids using head up displays). Incidentally, it is not just direct sight of the display that counts. The driver must not be able to see any relections of it either...

{Quote hidden}>Hi, > >I saw the two words 'automotive' and 'video', and I have to comment that >in the UK it is illegal to have a video display in view of the driver of >a car. I am unsure of the scope of this law (or if it has now been >dropped), since recently BMW were selling a top of the range model which >had a TV incorporated in the dash. I wonder if the law prohibits >specifically a CRT, and you get round it by using an LCD. > >>I'm working on an automotive project and I have need of a simple way >>to output video to a normal NTSC monitor. I've looked at a bunch of >>solutions and I think I found one that will work. When I researched >>this problem it came to me that maybe other people could use a self >>contained module to do the same thing. Remember that none of this is >>set in concrete and the features listed are only the one's I need. > >Why not use a Teletext style video generator. It is all >character-based, and gives you 40x24 characters (in the UK with PAL), 8 >colours, flash mode and graphics (where each character is a 3x2 pixel >block). A chip that does this was used in the BBC Micro (from Acorn >Computers), and I think the part number began 'SAA' (I am sure someone >has a BBC handbook just to hand. I seem to have omitted to bring mine). It's the SAA5050. There's others which are more integrated - the SAA5050 requires you to feed it data at the right rate; I wrote a driver once for a teletext display generator which consisted of an 8K SRAM and one other chip which addressed the SRAM, generated RGB & sync and had an I2C bus for communication. I'd guess it would be found in the appropriate Philips databook, which I don't have to hand. I do have my BBC service manual, though :-) Dave ------------------------------------------------------------ David Knell Tel: 01843 846558 Fax: 01843 846608 E-mail: .....daveKILLspam.....dave-ltd.co.uk

In your message dated Tuesday 20, August 1996 you wrote : > Hi, > > I saw the two words 'automotive' and 'video', and I have to comment that > in the UK it is illegal to have a video display in view of the driver of > a car. I am unsure of the scope of this law (or if it has now been > dropped), since recently BMW were selling a top of the range model which > had a TV incorporated in the dash. I wonder if the law prohibits > specifically a CRT, and you get round it by using an LCD. The law states that it is illegal to have a video display, sure, but if the video display is relaying information about the vehicle (speed etc.) it's ok. I believe Aston Martin use CRTs to provide this kind of info on some models (or at least it's an option). A video display with TV etc. is prohibited for obvious reasons and I think the BMW gets around it by disabling the display whilst in motion. > Why not use a Teletext style video generator. It is all > character-based, and gives you 40x24 characters (in the UK with PAL), 8 How about the 6845 CGA (?) VDU Controller, should be loads of them about and still fairly easy to use? > Anyway this is my opinion. You are welcome to it... =:^) > > Andy (the other one) > -- If you have a problem with excess cash, mail all those unwanted notes in plain packing to; EraseMEclintspam_OUTTakeThisOuTclintsmc.demon.co.uk

At 07:24 PM 20/08/96 +1000, you wrote: >Andy Errington <a.erringtonspam_OUTLANCASTER.AC.UK> > >> I saw the two words 'automotive' and 'video', and I have to comment that >> in the UK it is illegal to have a video display in view of the driver of >> a car. > >Curious. In Australia most taxis now have a display mounted above the instrument >panel which gives them information about what jobs are on offer, special > messages, etc. And of course many large trucks, buses, semis, etc. have a small TV mounted on the dash that provides a view to the driver from the rear of the vehicle (for safe reversing). ___Bob

> How about the 6845 CGA (?) VDU Controller, should be loads of them about and > still fairly easy to use? Here's why not to use the 6845, according to Steve Jobs in the article "An Interview: The Macintosh Design Team" in the February 1984 issue of Byte magazine: Steve Jobs: Do you realize that in an IBM PC the video board, just the black-and-white video plug-in card, has got way more chips than the entire Macintosh?" [...] Steve Jobs: I just thought I'd show this to you. This is the IBM video board; it's only video, nothing else. It's 69 integrated circuits, more chips than an entire Macintosh, and it basically does nothing. And it doesn't even do that very well. Chris Espinosa: Fourty percent more chips than the Mac. Steve Jobs: So that sort of gives you a feeling. And again, this just has the video on it. Macintosh, in addition to having video that's far higher in resolution and far faster, [...] [...] Steve Jobs: If you bite into that IBM display board, it'll totally flicker if you do it at the wrong time. He was referring to the IBM Monochrome Display Adapter (MDA). And although he mentions the low resolution and fliker, he left out an even more scathing criticism of the MDA card: It couldn't do bit-mapped graphics at all! For years video cards for PC clones have used high-integration ASICs (which usually contain a functional equivalent of a 6845). The 6845 was useful in the late 70s and early 80s, and could replace a fair number of TTL MSI chips, but it isn't a very good choice for new designs today because you still have to add a bunch of additional chips to make it do anything useful, and because it is an NMOS chip and draws quite a bit of power by today's standards. The 6845 might be useful if you want to build a one-of-a-kind device (and thus can't engineer something more modern), but the original poster was hoping to find something highly integrated, small, cheap, and with a simple bit-serial interface. The TI TMS9118 and TMS9918 families provided a much higher integration solution, and saw widespread use in the TI 99/4 home computer and the Japanese MSX computers. All you have to add is a pair of 16K*4 DRAMs. They have a simple 8-bit parallel interface. Unfortunately the availability is poor now, and they were also NMOS. Yamaha LSI makes the V9938 and V9958, which are software compatible upgrades from the TI parts, but I'm not sure how available they are. It would seem that the ideal single-chip solution could now be built in a DRAM process and contain a frame buffer, a simple processor, and a small masked ROM with code and character sets. I wonder whether any DRAM vendors have considered making such a thing. It's sort of a logical evolution from VRAM, although it probably wouldn't be useful in PCs or workstatons. Of course, you could just build a gate array and use a standard DRAM or VRAM and a DAC to build a three-chip solution. The gate array could even provide digitally generated NTSC or PAL color encoding. Cheers, Eric

> >> How about the 6845 CGA (?) VDU Controller, should be loads of them about and >> still fairly easy to use? > >Cheers, >Eric > > How about the Motorola 6847? (I believe this is the correct number.) I used it when I designed/built a CPM compatible back when I was in university. The chip was largely used in the video games of the time (able to display 24 x 40 characters and limited colour (NTSC) graphics). I believe the Radio Shack Colour TRS-80s used them. The chip internally provides a character generator with an burned in font, address and data lines and outputs composite video. The address and data bus can be accessed at any time (you have to tell the 6847 you're accessing the busses and it will tri-state it's outputs) or an output will tell you when a retrace is taking place so you don't get "snow" on the screen when you update. It's a pretty nifty solution, you just require the 6847, an SRAM (I used the full 8K!), some tri-state divers, and some miscellaneous analog parts (Including a colour-burst crystal). Myke Do you ever feel like an XT Clone caught in the Pentium Pro Zone?

> > How about the 6845 CGA (?) VDU Controller, should be loads of them about and > > still fairly easy to use? > > Here's why not to use the 6845, according to Steve Jobs in the article > "An Interview: The Macintosh Design Team" in the February 1984 issue of Byte > magazine: > > Steve Jobs: Do you realize that in an IBM PC the video board, just the > black-and-white video plug-in card, has got way more chips than the entire > Macintosh?" > [...] > Steve Jobs: I just thought I'd show this to you. This is the IBM video > board; it's only video, nothing else. It's 69 integrated circuits, more > chips than an entire Macintosh, and it basically does nothing. And it > doesn't even do that very well. [snip] > Steve Jobs: If you bite into that IBM display board, it'll totally flicker > if you do it at the wrong time. > > He was referring to the IBM Monochrome Display Adapter (MDA). And although > he mentions the low resolution and fliker, he left out an even more scathing > criticism of the MDA card: It couldn't do bit-mapped graphics at all! For > years video cards for PC clones have used high-integration ASICs (which > usually contain a functional equivalent of a 6845). Actually, sounds more like a CGA. The MDA does not have the flicker problems Jobs mentioned, and it also does more than display video (it's a printer port too--yippee). And the big reasons the CGA has so many chips are: <1> Complication of displaying both text and graphics <2> Poor design [e.g. their cursor circuit]

>How about the Motorola 6847? (I believe this is the correct number.) I >used it when I designed/built a CPM compatible back when I was in university. > >The chip was largely used in the video games of the time (able to display 24 >x 40 characters and limited colour (NTSC) graphics). I believe the Radio >Shack Colour TRS-80s used them. > >The chip internally provides a character generator with an burned in font, >address and data lines and outputs composite video. The address and data >bus can be accessed at any time (you have to tell the 6847 you're accessing >the busses and it will tri-state it's outputs) or an output will tell you >when a retrace is taking place so you don't get "snow" on the screen when >you update. > >It's a pretty nifty solution, you just require the 6847, an SRAM (I used the >full 8K!), some tri-state divers, and some miscellaneous analog parts >(Including a colour-burst crystal). The 6847 is a wonderful solution, BUT it is obsolete. As far as I know Motorola isn't making them any more. This is one of the single chip solutions I looked at, and I wanted to use it, but nobody could find a source for them. Some of the other chips were the TI 9918 (used in the TI 99/4a computer) and the Comodore custom chips in the VIC-20, C64, and Amigas. Atari also had a decent set of custom chips in its 8-bit home computers. All of these were great, but where did they go? I guess computer and home console game video system are so advanced now that there's no market for the low res stuff any more. There are, however, on-screen display generator chips out there for TVs, VCRs, and Camcorders... These are great for text only solutions since they handle almost everything for you, but they won't do graphics. The NEC uPC6145 does have 16 user definable characters in RAM though if you can count that... The search continues! Tim

>>The 6847 is a wonderful solution, BUT it is obsolete. As far as I know >>Motorola isn't making them any more. This is one of the single chip >>solutions I looked at, and I wanted to use it, but nobody could find a >>source for them. Some of the other chips were the TI 9918 (used in the >>TI 99/4a computer) and the Comodore custom chips in the VIC-20, C64, >>and Amigas. Atari also had a decent set of custom chips in its 8-bit >>home computers. All of these were great, but where did they go? I >>guess computer and home console game video system are so advanced >now >>that there's no market for the low res stuff any more. >> >>There are, however, on-screen display generator chips out there for >>TVs, VCRs, and Camcorders... These are great for text only solutions >>since they handle almost everything for you, but they won't do >>graphics. The NEC uPC6145 does have 16 user definable characters in >>RAM though if you can count that... Who else besides NEC makes these on-screen display generators. I've been thinking about doing a text only display... Thanks, Eric

> > Who else besides NEC makes these on-screen display generators. I've > > been thinking about doing a text only display... > > Me too. I've always been impressed by the crisp, clear textual displays > most VCRs and TVs can generate on an NTSC display. > > Are these chips something you could actually get along with > documentation ? Chances are good you might even be able to > gen-lock them (for overlay of text) to an incoming NTSC signal. Most of the VCR's and TV's use speciallized chips that have video character generaters built in. A few are based on familliar chips most are processors developed for the application area. None of the ones that I have seen are available in low volume programmable versions. Walter Banks fttp://http://www.bytecraft.com

> From: Richard Katezansky > To: Multiple recipients of list PICLIST > Subject: Re: Serial Video Display Module > Date: Wednesday, 21 August 1996 16:42 > > >Who else besides NEC makes these on-screen display generators. I've > >been thinking about doing a text only display... > > > > Thanks, > > Eric > > > Fujitsu- MB88303, 88323, 88325 > > Mitsubishi- M50554 ect. > > Most of these are 20-24 characters per line 10-12 lines per screen. > > All overlay on a video source some will do color if generating their own sync. Motorola make an Advanced Monitor On-Screen Display chip, the MC141543, which has inbuilt 128 character and graphic symbol ROM, 3 selectable resolutions- 320, 480, or 640 dots per line, I2C interface. Font is 10x16 with various options like bordering, shadowing, colour (max. 4 colours per row). They also make a Color Television Composite Video Overlay Synchronizer, the MC1378, to overlay an RGB signal onto a external video signal, PAL or NTSC. Gary. -------------------------------------------- Email: RemoveMEGary.FowlerTakeThisOuTdsto.defence.gov.au Phone: +61 8 8259 5767 Fax: +61 8 8259 5672 Defence Science & Technology Organisation PO Box 1500, Salisbury, South Australia 5108 --------------------------------------------

Here is a message that appeared on the Stamps list, sorry if any of you have see n it before. Andy > Just happened to have read the September edition of Electronics World (published in the UK but also available in the US I understand). Article re using the NEC uPD6145 chip for putting characters onto a video signal--- PAL/SECAM/NTSC etc. Chip uses SPI link and looking at the rest of the circuit it would suggest it would be really Stamp friendly to implement. If anyone gets a Stamp version up and running before me, please give me a call. (Author of the article is- Ian Polczynski at 77, Glanton Way, Dianella, Western Australia 6062) -- Edward Buckley - To subscribe -or- unsubscribe send e-mail to spamBeGonemajordomospamBeGoneparallaxinc.com and - put SUBSCRIBE stamps -or- UNSUBSCRIBE stamps in the body of the message Attachment converted: wonderlandthree:WINMAIL.DAT (????/----) (0000753B)

In message <TakeThisOuTm0utJwa-000NVbCEraseMEspam_OUTn0jcf.com> RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU writes: > Eric Thompson wrote: > > > > Who else besides NEC makes these on-screen display generators. I've > > been thinking about doing a text only display... > > Me too. I've always been impressed by the crisp, clear textual displays > most VCRs and TVs can generate on an NTSC display. > > Are these chips something you could actually get along with > documentation ? Chances are good you might even be able to > gen-lock them (for overlay of text) to an incoming NTSC signal. I've been looking at the circuit for a Pace satellite receiver, this uses an on-screen display, which can be either gen-locked over the picture, or replace the existing picture completely with a coloured background. The chip used is the M50555001P from Mitsubishi. It's controlled via an I2C bus and enable line, and just requires composite sync, the incoming video enters one pin, and leaves via another with the displayed text overlayed. There are of course a handfull of components around the chip, including a 17.734MHz xtal (for PAL) and an LC circuit for generating the bit-clock. Like any of these sorts of circuits, the problems seem to be finding out what data needs supplying via the bus. Do Mitsubishi have a web site, where hopefully they may give details like this?. BTW, the reason for looking at the circuit was to try and add a gen-locked time display to a video camera signal for recording on security tapes. Nigel. /----------------------------------------------------------\ | Nigel Goodwin | Internet : nigelgEraseME.....lpilsley.demon.co.uk | | Lower Pilsley | | | Chesterfield | | | England | | \----------------------------------------------------------/