News Ultimarc Emu Loader Programming MAME Artwork progetto-SNAPS MAMEUI HBMAME EmuChat Hardware The Loony Bin MAME Artwork X

Entrance | Main Index | Search | New user | Login | Who's Online | FAQ | Rules

MAMEWorld >> The Loony Bin Index   Flat

italie MAME owes italie many thank yous, hah Reged: 09/20/03 Posts: 15246 Loc: BoomTown Send PM Re: Xtal compensation theory 101: Part 2 07/03/12 05:29 PM Reply > > > "Reverse error generation"? "Cancellation signal"? > > > You mean, as opposed to a lookup table containing values such as "500000" and > > > "500012"? > > > > Yes. One solid difference is that most of these error corrections are generated > real > > time (analog). A digital look-up table would require a huge resolution to be > > effective at anything other than one very precise fixed temperature (see oven > > oscilator, the only way this principle works to any degree of accuracy). > > What do you mean by a "huge resolution"? Do you mean lost of entries? Or do you mean > that the entries themselves would have a lot of digits? > > What you could do is: instead of thinking in terms of cycles per second, think in > terms of (pico- or femto-)seconds per cycle. The table would have entries like: > > (figures pulled out of ass, for illustration only) > 20.0 deg C: 0.000 000 999 999 95 sec > 20.1 deg C: 0.000 001 000 000 00 sec > 20.2 deg C: 0.000 001 000 000 07 sec > 20.3 deg C: 0.000 001 000 000 18 sec > > and you're smart enough to figure out what happens with each oscillation of the > crystal. So you have built your uber precise table based upon a very controlled data collection in a stable environment... Then your dog sneezed on the clock... Your table has just been invalidated, enjoy your recalibration. Xtals are extremely sensitive to many factors, many of which I haven't even touched on. If you aren't compensating for them in some way, your tweaks are random and inconsequential minutes after they are implemented.

Entire thread Subject Posted by Posted on What time is it? (rant) amused 07/02/12 12:46 PM Did an elephant sit on your fence? GatKong  07/02/12 09:51 PM For reasons I can't explain, I love this thread. *nt* Stiletto  07/02/12 05:51 PM Re: What time is it? (rant) Gor  07/02/12 04:21 PM Re: What time is it? (rant) amused  07/02/12 05:05 PM Re: What time is it? (rant) Gor  07/02/12 06:45 PM Re: What time is it? (rant) JWJr  07/02/12 05:25 PM Re: What time is it? (rant) amused  07/02/12 07:18 PM Re: What time is it? (rant) italie  07/02/12 07:30 PM Re: What time is it? (rant) amused  07/02/12 07:36 PM Re: What time is it? (rant) italie  07/02/12 07:48 PM Re: What time is it? (rant) amused  07/03/12 03:45 AM Xtal compensation theory 101: Part 1 italie  07/03/12 05:45 AM Xtal compensation theory 101: Part 2 italie  07/03/12 06:23 AM Re: Xtal compensation theory 101: Part 2 amused  07/03/12 11:04 AM Re: Xtal compensation theory 101: Part 2 italie  07/03/12 01:42 PM Re: Xtal compensation theory 101: Part 2 amused  07/03/12 04:24 PM Re: Xtal compensation theory 101: Part 2 italie  07/03/12 05:29 PM Re: Xtal compensation theory 101: Part 2 Bekki Doll  07/07/12 12:05 AM Re: Xtal compensation theory 101: Part 2 Vas Crabb  07/03/12 04:27 PM Re: Xtal compensation theory 101: Part 2 Gor  07/03/12 05:20 PM Xtal compensation theory 101: Part 3 italie  07/03/12 07:25 AM Re: What time is it? (rant) lharms  07/02/12 10:01 PM Re: What time is it? (rant) amused  07/03/12 03:50 AM Just one question (yes, only one) italie  07/02/12 02:02 PM Re: Just one question (yes, only one) amused  07/02/12 02:40 PM Re: Just one question (yes, only one) Tomu Breidah  07/02/12 03:52 PM Re: Just one question (yes, only one) italie  07/02/12 03:47 PM Re: Just one question (yes, only one) amused  07/02/12 04:02 PM Re: Just one question (yes, only one) italie  07/02/12 04:22 PM Re: Just one question (yes, only one) amused  07/02/12 05:07 PM Re: Just one question (yes, only one) italie  07/02/12 07:51 PM Re: Just one question (yes, only one) TriggerFin  07/02/12 08:36 PM Re: Just one question (yes, only one) italie  07/02/12 09:07 PM

Extra information Permissions Moderator:  GatKong  1 registered and 191 anonymous users are browsing this forum. You cannot start new topics You cannot reply to topics HTML is enabled UBBCode is enabled Thread views: 2810

Browser Test | Delete Cookies atom-guru atom-guru atom-guru atom-guru UBB.threads™ 6.3.2