APU Sweep: Revision history

8 February 2024

• curprev 21:2321:23, 8 February 2024‎ Lidnariq talk contribs‎ 4,226 bytes −97‎ →‎Updating the period: enumerate things a little more clearly, fix DRY, move enumeration in
• curprev 21:1721:17, 8 February 2024‎ Lidnariq talk contribs‎ 4,323 bytes +40‎ →‎Registers: mention shift count=0 special handling

1 October 2023

• curprev 02:2902:29, 1 October 2023‎ Tepples talk contribs‎ 4,283 bytes +22‎ →‎Calculating the target period: Previous wording wasn't clear enough that $4001 and $4005 writes also change the target period. Reported by Vingal on Discord.

6 May 2023

• curprev 23:2623:26, 6 May 2023‎ Lidnariq talk contribs‎ m 4,261 bytes −33‎ Reverted edits by Lidnariq (talk) to last revision by Tepples Tag: Rollback
• curprev 23:2623:26, 6 May 2023‎ Lidnariq talk contribs‎ 4,294 bytes +33‎ →‎Calculating the target period: clarify that pulse 1 "ones' complement" does not overflow and cause muting Tag: Reverted
• curprev 23:2323:23, 6 May 2023‎ Tepples talk contribs‎ 4,261 bytes +41‎ →‎Calculating the target period: A user was seeing Bomberman do $08 on pulse 1 and assuming that the sum of -1 was causing wraparound to -1, which as an unsigned integer $FFFFFFFF, which is greater than $7FF, and concluding that this was causing muting.

12 June 2022

• curprev 03:0303:03, 12 June 2022‎ NobleEightfold talk contribs‎ m 4,220 bytes +47‎ text tweaks for clarity
• curprev 02:5402:54, 12 June 2022‎ NobleEightfold talk contribs‎ m 4,173 bytes +91‎ Minor formatting changes and clarifying words added

31 March 2021

• curprev 23:3923:39, 31 March 2021‎ Lidnariq talk contribs‎ 4,082 bytes −41‎ →‎Muting: rewrite for clarity

20 July 2018

• curprev 15:2315:23, 20 July 2018‎ Tepples talk contribs‎ 4,123 bytes −1‎ →‎Updating the period: Reflect rename of "not in range" to "muting the channel" elsewhere
• curprev 15:1915:19, 20 July 2018‎ Tepples talk contribs‎ 4,124 bytes +8‎ →‎Muting: Avoid passive voice per https://forums.nesdev.com/viewtopic.php?p=221611#p221611

29 June 2017

• curprev 01:0001:00, 29 June 2017‎ Tepples talk contribs‎ m 4,116 bytes −2‎ →‎Updating the period: damn you markdown muscle memory
• curprev 00:5700:57, 29 June 2017‎ Tepples talk contribs‎ 4,118 bytes +5‎ Mention earlier that the unit is half-frames
• curprev 00:5700:57, 29 June 2017‎ Tepples talk contribs‎ 4,113 bytes −266‎ →‎Updating the period: Zero before reload does the same thing whether reload is set or clear. Thus it can be factored out into a separate step.

7 January 2017

• curprev 05:1405:14, 7 January 2017‎ Tepples talk contribs‎ 4,379 bytes +86‎ →‎Updating the period: muting does not freeze the period divider per http://forums.nesdev.com/viewtopic.php?p=186150#p186150

28 December 2016

• curprev 17:0717:07, 28 December 2016‎ Tepples talk contribs‎ m 4,293 bytes +29‎ →‎Calculating the target period: left out some words in a refactoring of the "shift amount is zero" logic
• curprev 17:0317:03, 28 December 2016‎ Tepples talk contribs‎ 4,264 bytes +632‎ ch1/ch2 differences and muting are more related to the target period than to updates
• curprev 16:1116:11, 28 December 2016‎ Tepples talk contribs‎ 3,632 bytes −16‎ Make calculation of target period more distinct as a step in the sweep unit's operation; reiterate approximate rate of APU Frame Counter

22 August 2016

• curprev 04:5204:52, 22 August 2016‎ Furrykef talk contribs‎ m 3,648 bytes +1‎ standard pronunciation of "NES" is "en ee ess", so "an"

9 March 2014

• curprev 14:4414:44, 9 March 2014‎ Rainwarrior talk contribs‎ m 3,647 bytes +33‎ note that the reload flag is cleared when clocked

16 May 2013

• curprev 01:5501:55, 16 May 2013‎ Zepper talk contribs‎ m 3,614 bytes −5‎ No edit summary

7 May 2013

• curprev 15:0315:03, 7 May 2013‎ Ulfalizer talk contribs‎ 3,619 bytes +50‎ Sweep needs to be enabled too to adjust the period :P

6 May 2013

• curprev 14:5614:56, 6 May 2013‎ Ulfalizer talk contribs‎ 3,569 bytes +230‎ Note that the silencing overflow still happens with a shift count of zero (confirmed in Visual 2A03)
• curprev 09:3609:36, 6 May 2013‎ Ulfalizer talk contribs‎ 3,339 bytes +289‎ Clarify that the silencing-even-when-disabled behavior is only relevant for overflow

5 May 2013

• curprev 14:0314:03, 5 May 2013‎ Ulfalizer talk contribs‎ 3,050 bytes +38‎ Small silencing clarification
• curprev 12:4312:43, 5 May 2013‎ Ulfalizer talk contribs‎ m 3,012 bytes +3‎ Add an 'is'
• curprev 12:4012:40, 5 May 2013‎ Ulfalizer talk contribs‎ 3,009 bytes +389‎ Describe exactly when the period update happens and use the internal version of what's going in instead of the "clocked before reload" version (as it isn't any more complicated)
• curprev 09:4909:49, 5 May 2013‎ Ulfalizer talk contribs‎ 2,620 bytes +77‎ Internally, the target period is calculated continuously by the adder

26 May 2012

• curprev 20:0120:01, 26 May 2012‎ Rainwarrior talk contribs‎ m 2,543 bytes +17‎ APU category

18 May 2011

• curprev 15:0215:02, 18 May 2011‎ Tepples talk contribs‎ 2,526 bytes +245‎ In silicon, combinational logic begins to compute the next state immediately after the current state is updated.

14 May 2011

• curprev 17:0717:07, 14 May 2011‎ Tepples talk contribs‎ m 2,281 bytes −8‎ use the term "target period" throughout
• curprev 16:5616:56, 14 May 2011‎ Quietust talk contribs‎ 2,289 bytes +14‎ clarify
• curprev 16:4616:46, 14 May 2011‎ Quietust talk contribs‎ 2,275 bytes +104‎ the problem isn't in pulse 2, but in pulse 1 - pulse 2 adds the two's complement during subtraction (as it should), but pulse 1 adds the ONE'S complement due to its carry input being hardwired

31 December 2010

• curprev 06:3606:36, 31 December 2010‎ Jwdonal talk contribs‎ m 2,171 bytes +167‎ Thought of an easier/better way to clarify "shifter result".
• curprev 05:5005:50, 31 December 2010‎ Jwdonal talk contribs‎ m 2,004 bytes +15‎ Added a very important clarification that was driving me bonkers. This edit is a result of the following thread: http://nesdev.parodius.com/bbs/viewtopic.php?p=72158

11 March 2010

• curprev 19:5819:58, 11 March 2010‎ Tepples talk contribs‎ 1,989 bytes +46‎ why it works
• curprev 19:5619:56, 11 March 2010‎ Tepples talk contribs‎ 1,943 bytes +133‎ how to fully disable

12 June 2009

• curprev 15:1115:11, 12 June 2009‎ Banshaku talk contribs‎ m 1,810 bytes +1,810‎ Created page with 'A NES APU sweep unit can be made to periodically adjust a pulse channel's period up or down. Each sweep unit contains the following: divider, ...'