Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!gegeweb.42!gegeweb.eu!nntpfeed.proxad.net!proxad.net!feeder1-2.proxad.net!usenet-fr.net!de-l.enfer-du-nord.net!feeder2.enfer-du-nord.net!news.bbs-scene.org!not-for-mail From: Jerry Newsgroups: comp.sys.apple2.programmer Subject: Re: Converting HGR to DHGR Date: Sat, 21 Jan 2012 02:53:56 -0700 Organization: bbs-scene usenet news Lines: 37 Message-ID: References: <1cac2bf1-26df-4733-9a87-5a90a5e7c612@o9g2000yqa.googlegroups.com> <0c35bd21-7af2-41b1-a96e-fbd69aa33442@t8g2000yqg.googlegroups.com> <892a42af-44e2-4170-8f2a-8cd606e8c809@u2g2000vbe.googlegroups.com> <6055580d-a21b-49d3-b82b-57414beeff21@b20g2000yqb.googlegroups.com> NNTP-Posting-Host: d50-99-206-130.abhsia.telus.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: news.bbs-scene.org 1327139656 31095 50.99.206.130 (21 Jan 2012 09:54:16 GMT) X-Complaints-To: abuse@bbs-scene.org NNTP-Posting-Date: Sat, 21 Jan 2012 09:54:16 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) Cancel-Lock: sha1:kSqom3rIXPnrxrPeW9iq0sFdNZU= Xref: x330-a1.tempe.blueboxinc.net comp.sys.apple2.programmer:120 Vladimir Ivanov writes: > On Wed, 18 Jan 2012, BLuRry wrote: > >> 1 bit shift for DHGR though?? > > Not likely. If you have setup with color monitor just try it. 80-column mode, and DHGR actually starts seven bits (14.318180 MHz periods) sooner (one 80-column character width) than 40-column mode, which explains the shift in colors if either you don't do the shift to compensate, or you don't simulate the whole dot stream coming out of the shift registers. Try this on a IIe or IIc to see the effect: 1 D = 500 2 PR# 3: PRINT " " 5 GOTO 100 10 PRINT CHR$ (17); 20 FOR X = 1 to D: NEXT 30 PRINT CHR$ (18); 40 FOR X = 1 to D: NEXT 50 GOTO 10 100 HGR : POKE 49246,0 101 DATA 160,0,132,0,162,32,134,1,141,84,192,177,0,141,85,192,145,0,200 ,208,243,230,1,202,208,238,96 102 FOR A = 768 TO 794: READ X: POKE A,X: NEXT 110 HCOLOR= 3: HPLOT 0,0: CALL 62454 120 GOTO 10 You will see the left and right borders moving left and right a bit as the display switches from 80 columns to 40 columns and back. -- -- Jerry awanderin at yahoo dot ca