On Saturday 26 August 2006 01:10, Jon Smirl wrote: > On Fri, 25 Aug 2006 23:49:01 +0000, mykrowatt wrote: > > I didn't see this message earlier. > > Tim and I have been discussing support for fixed-frequency displays > > off-line, trying to whittle down the on-chip logic to the absolute > > Where are fixed frequency displays being used? I haven't seen one since > around 1996 or so and that was on a Sun system.
I'm as bemused as you about the issue. I've seen *one* fixed frequency monitor, and that was sitting on a shelf at Snell & Wilcox (http://www.snellwilcox.com/). Admittedly it was plugged into a real-time HDTV compositing system with 64 GB of RAM at the time... can you even buy them any more? In addition, my suggestion of, 'Borrow your friend's multisync for long enough to set up the card's PROM for your super-duper fixed-frequency monitor,' seems to be completely unacceptable for some reason. I've said it before, I'll say it again: an inordinate amount of time seems to be being spent putting in features that the _vast_ majority of users of TRV10 will _never_ need. Embedded systems developers will either have the PROM pre-programmed, or will eliminate the PROM entirely (possibly by emulating it). Users of OGC1 or other TRV10-based cards will either have a multisync monitor, be able to borrow one, ask their vendor to pre-program the card, or be able to log into their computer over serial/SSH/VNC/some other remote login protocol. Having said that, chaining onto the end of the SPI bus is the most reasonable solution I've heard so far. I'd suggest a PIC + serial port as the tidiest solution, requiring the following components: - 9-pin female DB9 connector - MAX233 (or similar RS232 level-shifter/line driver) - 8-bit PIC - 5-pin SPI connector - a couple of decoupling caps (probably a couple of 0.1 uF ceramics would do) You could probably fit the entire thing inside a 9-pin DB9 housing without breaking a sweat. If anyone's interested, I'll make up a PCB layout & a proper BOM for this, or a very similar circuit using an FTDI USB-RS232 converter chip. Usage would be as follows: before turning on the card, pre-program the PIC with the memory image wanted using the RS232 (or USB) link. Plug cable into card. Power on card. With some judicious use of diodes, you could probably get the PIC card to work as a standalone programmer for batch jobs, without needing to be connected by serial except for changing the desired memory image. For vendor & factory use, it would be nice to be able to (re)configure the card without having to put it into a PCI slot and power it up. Is there going to be any scope for this? At the moment, how are you planning to have the factory image programmed into the ROM? As you guys are probably aware, attention to manufacturing detail[1] can make or break an consumer electronics project. Quick question for users of fixed-frequency monitors: how do you change your BIOS settings, seeing as the BIOS of every PC-compatible I've ever seen uses VGA? I'm curious... I'm kind of assuming that you're not using PCs! Peter :) [1] If you look inside a recent Sony or Nokia phone you'll see that the circuit boards have components on one side almost exclusively. Why? They could pack the circuits in much closer if they put parts on both. Reason: a second run through the solder paste stencil, populate, reflow process takes time. The saving from avoiding a second assembly sequence easily outweighs the cost of a larger PCB. -- Fisher Society publicity officer http://tinyurl.com/o39w2 CUSBC novices, match and league secretary http://tinyurl.com/mwrc9 Quake II build tools maintainer http://tinyurl.com/fkldd v2sw6YShw7$ln5pr6ck3ma8u6/8Lw3+2m0l7Ci6e4+8t4Eb8Aen5+6g6Pa2Xs5MSr5p4 hackerkey.com
pgpqNVeWO25Es.pgp
Description: PGP signature
_______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
