From filker@newton.physics.metu.edu.tr Wed Jul 13 10:27:13 1997 Status: RO X-Status: Path: news.metu.edu.tr!news1.usf.edu!atl-news-feed1.bbnplanet.com!smartdna!news-xfer.mccc.edu!news.radio.cz!nntp.uio.no!newsfeed.nacamar.de!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!infeed2.internetmci.com!newsfeed.internetmci.com!in1.uu.net!140.142.64.3!news.u.washington.edu!homer33.u.washington.edu!rrcc From: Raymond Carlsen Newsgroups: comp.emulators.cbm,comp.sys.cbm Subject: Re: 1571 Problem?? Date: Sun, 13 Jul 1997 10:27:13 -0700 Organization: University of Washington Lines: 17 Message-ID: References: <33C857F8.33A3@gate.net> NNTP-Posting-Host: homer33.u.washington.edu Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII NNTP-Posting-User: rrcc To: Paul Graber In-Reply-To: <33C857F8.33A3@gate.net> Xref: news.metu.edu.tr comp.emulators.cbm:16330 comp.sys.cbm:64328 > Help! I think my 1571 is trashed. Whenever I power it on the green light > just stays lit and the drive spins forever no matter what I do, unless I > power it back off. Does anybody know what the problem is? Paul, As in the 1541, when the drive cannot finish the startup sequence, it produces those symptoms. In the 1541, the DOS ROM is usually the culprit. It is socketed in both drives. You might try reseating the socketed chips. Sometimes a bad connection develops between the chip and the socket. Lift up on each end of the chip and then press it back down... or just mash down on them, then try the drive again. Are there any other drives laying around that you could use to swap out the ROM chip as a diagnostic? If it's bad, this might be a good time to upgrade to JiffyDOS. Ray Carlsen CARLSEN ELECTRONICS... a leader in trailing-edge technology. From filker@newton.physics.metu.edu.tr Wed Jul 13 20:00:45 1997 Status: RO X-Status: Path: news.metu.edu.tr!news1.usf.edu!atl-news-feed1.bbnplanet.com!news.bbnplanet.com!smartdna!news-xfer.mccc.edu!news.maxwell.syr.edu!News1.Ottawa.iSTAR.net!News4.Ottawa.iSTAR.net!news.istar.net!news.inforamp.net!news From: crs0794@inforamp.net (Geoffrey Welsh) Newsgroups: comp.sys.cbm Subject: Re: 9090 Hard Drives Date: 13 Jul 1997 20:00:45 GMT Organization: Izot's Swamp Lines: 19 Message-ID: <5qbc5d$ggi@news.inforamp.net> References: <33C336D7.3473@intuit.com> <5q3eca$k41$1@mathserv.mps.ohio-state.edu> NNTP-Posting-Host: ts69-10.tor.istar.ca X-Newsreader: Forte Free Agent 1.1/32.230 (posted to comp.sys.cbm and mailed to dfevans@bbcr.uwaterloo.ca (David Evans)) On Fri, 11 Jul 1997 20:02:57 GMT, dfevans@bbcr.uwaterloo.ca (David Evans) wrote: >In article <5q3eca$k41$1@mathserv.mps.ohio-state.edu>, >Ethan Dicks wrote: >> >>It's attached to a _SASI_-MFM board which is attached to the "DOS Board", >>the part with the IEEE interface and C= DOS. > > So you're saying that if we have a SASI disk around we could use it? :) Better yet, if you have a comparable MFM drive, you can use it with the existing SASI-based controller. -- Geoffrey Welsh; crs0794@inforamp.net; http://home.inforamp.net/~crs0794/ From filker@newton.physics.metu.edu.tr Tue Jul 12 22:05:48 1997 Status: RO X-Status: Path: news.metu.edu.tr!news1.usf.edu!atl-news-feed1.bbnplanet.com!news.bbnplanet.com!smartdna!news-xfer.mccc.edu!hub.org!news-feed.inet.tele.dk!europa.clark.net!news-peer.sprintlink.net!news-pull.sprintlink.net!news-in-east.sprintlink.net!news.sprintlink.net!Sprint!131.103.1.114!chi-news.cic.net!ftpbox.mot.com!newsfeed.acns.nwu.edu!news.acns.nwu.edu!merle!judd From: judd@merle.acns.nwu.edu (Stephen Judd) Newsgroups: comp.sys.cbm,comp.sys.sinclair Subject: Re: Elite line routine (was Re: spectrum faster in 3D) Date: 12 Jul 1997 22:05:48 GMT Organization: Northwestern University, Evanston, IL Lines: 83 Message-ID: <5q8v3s$m38@news.acns.nwu.edu> References: <33A9DD07.153E@skynet.be> <33C4CD48.41C6@wi.leidenuniv.nl> <5q4jpr$4cu@news.acns.nwu.edu> <11449.imc@comlab.ox.ac.uk> Reply-To: sjudd@nwu.edu (Stephen Judd) NNTP-Posting-Host: merle.acns.nwu.edu Xref: news.metu.edu.tr comp.sys.cbm:64310 comp.sys.sinclair:8991 In article <11449.imc@comlab.ox.ac.uk>, Ian Collier wrote: >In article <5q4jpr$4cu@news.acns.nwu.edu>, sjudd@nwu.edu (Stephen Judd) wrote: >>Now, I have a question for anyone interested: What is the Bresenham >>algorithm? > >They are, of course, more or less equivalent (it's down to which way >you go when the answer is exactly zero) and so I guess they can both >be referred to as Bresenham's algorithm. > >The derivation is something like this (actually I just went to the library >so at least one text gives this derivation (-: ). Thanks -- I've gone through it, still find it confusing, and will hence go through it again later :). For what it's worth, my own derivation goes like: From the definition of a line: dy=m*dx where m=slope. That is, if I take a step of size dx in the x direction, I will take a corresponding step dy in the y-direction. Since we're on a computer, steps of interest are of size 1. Let's say we move in the x-direction by one at each step: x=x+1 y=y+m where m=Dy/Dx i.e. (y2-y1)/(x2-x1). So, if we just keep a running sum of m at each step, once that sum is >1 it's time to take a step in y. The running sum just looks like m + m + m + ... = Dy/Dx + Dy/Dx + Dy/Dx + ... = (Dy + Dy + Dy + ...)/Dx So, the idea is to just keep adding Dy to itself, and once it is larger than Dx, the fraction is >1 and it is time to take a step in y. By then subtracting off Dx, we retain the remainder. The only thing to realize is that by starting this counter off at Dx/2 we are in effect rounding the numbers up (we've just added 0.5 to the fraction), which in turn has the effect of splitting one of the horizontal line segments evenly between the first and the last point. So, by my reckoning, the 2*dy-dx junk is all just a complicated way of starting a counter at dx/2. >>(I've also heard of Bresenham circle algorithms, but have never seen >>one of those either). > >It can be derived in a manner rather similar to the above reasoning, but >instead here is my take on the matter. This may not be exactly Bresenham's >algorithm but it's similar in style and totally amazing in its simplicity if >you have never seen one before. Again, thanks. The circle routine I came up with was Y = Radius X = 0 A = Radius/2 :loop Plot4(x,y) ;Could just use Plot8 X = X + 1 A = A - X if A<0 then A=A+Y : Y=Y-1 if X < Y then :loop As you say, you can use plot8, but in BLARG I actually computed the next eighth by basically reversing the above steps, and using plot4. That way I could maintain four pointers and make the plotting very fast. I think I put a derivation in C=Hacking somewhere; what it does is solve the differential equation for a circle dy/dx = -x/y using a running sum, similar to the line routine above. Actually when I first wrote it I had a very strange geometric/pictoral reasoning -- the above derivation came a day later. I actually have a secret belief that there's something deeper going on, because the routine is just too beautiful, and works too well across all values of R. Anyways, it looks pretty similar to your routine, and it continues to amaze me that it actually works, and works incredibly well. -S From filker@newton.physics.metu.edu.tr Wed Jul 13 00:52:58 1997 Status: RO X-Status: Path: news.metu.edu.tr!news1.usf.edu!atl-news-feed1.bbnplanet.com!news.bbnplanet.com!smartdna!news.io.com!news.eden.com!uunet!in3.uu.net!144.212.100.12!news.mathworks.com!chi-news.cic.net!ftpbox.mot.com!newsfeed.acns.nwu.edu!news.acns.nwu.edu!merle!judd From: judd@merle.acns.nwu.edu (Stephen Judd) Newsgroups: comp.sys.cbm,comp.sys.sinclair Subject: Re: Elite line routine (was Re: spectrum faster in 3D) Date: 13 Jul 1997 00:52:58 GMT Organization: Northwestern University, Evanston, IL Lines: 51 Message-ID: <5q98ta$pmd@news.acns.nwu.edu> References: <33A9DD07.153E@skynet.be> <33C3830B.446B@wi.leidenuniv.nl> <33C4CD48.41C6@wi.leidenuniv.nl> <5q5a8o$fl6@ds2.acs.ucalgary.ca> Reply-To: sjudd@nwu.edu (Stephen Judd) NNTP-Posting-Host: merle.acns.nwu.edu Xref: news.metu.edu.tr comp.sys.cbm:64314 comp.sys.sinclair:8999 In article <5q5a8o$fl6@ds2.acs.ucalgary.ca>, Alvin R. Albrecht wrote: > > >Here we go: one last line draw routine. What's new: I've adopted >Stephen's plot in a byte approach and I've dropped the stack as a source Good; I hoped that someone would clue in to the bit unrolling ala Elite. Since Braben and Bell seemed to be Z80 guys, I assumed the Elite routine was pretty much translated code. But... >DRAW EXX 4 > > SUB C 4 ; A=A-dy > JR C,fixy5 7/12 ; if A<0 next y pixel >back5 SET 5,E 8 ; plot bit 5 > > SUB C 4 ; These are all the same. > JR C,fixy6 7/12 ; Really. >back6 SET 6,E 8 ; But for different bits, o'course How were you planning on terminating the line? Or is this supposed to draw lines within +/-8 pixels? Not exactly a line routine I'd want to use for a game... (Might make for an interesting demo effect though). If I were to do a chunky 6510 equivalent, it would look like SBC #blah 2 BCC fixy1 2 four cycles. But I wouldn't want to do that :). Incidentally, it is possible to rewrite my 10/40 routine as an 8/43 routine. I also take it as obvious that if speed were the real concern, a 10/40 (note to self: do taxes early this year) routine would be user for lines with slope <1/2, and an e.g. 28 cycle routine for lines with slope >1/2. So, minimum of 8-10 or so cycles and a max of, hmmm... 28-32. (And yes, I'm ignoring things like moving through columns, which might add a cycle to the average; and yes, the 8 cpp routine has a slightly more involved setup.) So, why don't you fix up the routine to draw lines correctly, and then we can compare. -S From filker@newton.physics.metu.edu.tr Sat Jul 9 13:20:31 1997 Status: RO X-Status: Path: news.metu.edu.tr!news1.usf.edu!atl-news-feed1.bbnplanet.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!newsfeed.direct.ca!news-sea-19.sprintlink.net!news-in-west.sprintlink.net!128.122.128.2!cmcl2.nyu.edu!newsserv.cs.sunysb.edu!news.cc.sunysb.edu!news-pen-15.sprintlink.net!news.nysernet.net!news-pull.sprintlink.net!news-in-east.sprintlink.net!news-peer.sprintlink.net!news.sprintlink.net!Sprint!howland.erols.net!europa.clark.net!dispatch.news.demon.net!demon!delos.dra.hmg.gb!server1.netnews.ja.net!lyra.csx.cam.ac.uk!news.ox.ac.uk!news From: imc@ecs.ox.ac.uk (Ian Collier) Newsgroups: comp.sys.sinclair,comp.sys.cbm Subject: Re: Spectrum Emulator for C64 Date: 9 Jul 1997 13:20:31 GMT Organization: Oxford University Computing Laboratory, UK Message-ID: <11428.imc@comlab.ox.ac.uk> References: <339d8a2a.3224107@news.demon.co.uk> <11408.imc@comlab.ox.ac.uk> NNTP-Posting-Host: boothp2.ecs.ox.ac.uk X-Local-Date: Wednesday, 9th July 1997 at 2:20pm BST Lines: 27 Xref: news.metu.edu.tr comp.sys.sinclair:9028 comp.sys.cbm:64343 In article , "Bruce R. McFarling" wrote: > BTW, a fully unrolled loop (obviously) doesn't care about byte >order. However, if we restricted the 8-byte BCD number to be page aligned, >the following can be put into RAM somewhere (you'll notice that it aint >ROMMable) >op2 = *+11 >ADD16DEC: > STA OP2+1 ; 4 > CLC ; 2 > TYA ; 2 > ADC #8 ; 2 > STA OP2 ; 4 > CLC ; 2 > LDX #(0-8) ; 2 > - LDA $FF00,X ; 5 > ADC OP1,X ; 4 > STA OP1,X ; 4 > INX ; 2 > BNE - ; 3/2 > RTS ; 5 What is the question to which this is the answer? What does LDX #(0-8) mean, and which location is op2? -- ---- Ian Collier : imc@comlab.ox.ac.uk : WWW page (including Spectrum section): ------ http://www.comlab.ox.ac.uk/oucl/users/ian.collier/imc.html From filker@newton.physics.metu.edu.tr Fri Jul 15 00:49:09 1997 Status: RO X-Status: Path: news.metu.edu.tr!news1.usf.edu!atl-news-feed1.bbnplanet.com!smartdna!news.radio.cz!nntprelay.mathworks.com!howland.erols.net!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!firehose.mindspring.com!news.mindspring.com!usenet From: Radioactive Warrior Newsgroups: comp.emulators.cbm,comp.sys.cbm Subject: Re: Where is the DOS chip on the 1571? Date: Tue, 15 Jul 1997 00:49:09 +0000 Organization: :Critical Mass for our Unstable Society: Lines: 34 Message-ID: <33CAC905.6C2E@mindspring.com> References: <33C95BF4.7977@gate.net> Reply-To: radwar@orl.mindspring.com NNTP-Posting-Host: user-38lc3gm.dialup.mindspring.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Server-Date: 15 Jul 1997 04:39:29 GMT X-Mailer: Mozilla 2.02 (Macintosh; U; PPC) Xref: news.metu.edu.tr comp.emulators.cbm:16356 comp.sys.cbm:64362 Raymond A. Madison, Sr. wrote: > > On Sun, 13 Jul 1997, Paul Graber wrote: > > > Hi, > > I am trying to find the DOS chip on my 1571. I have found two chips > > which can be pulled off the board, one is small and one is longer, so I > > am assuming one of these is it or both. Which is which. And what is the > > other one for. > > > > Any help would be appreciated. > > > > Thanks > > -- > > Paul Graber > > gedwyn@gate.net > > "Ultima Dragon and Classic Gaming enthusiast" > > > > > The larger chip is the DOS chip. I believe you have to remove the > "powerbox" to get to it. Huh? Well, if the "DOS chip" means the 1571 ROM then it is the smaller (28 pin) chip. The larger (40 pin) chip is the 6526 CIA chip, yes the same used in the c64... The 1571 accesses this extra I/O chip at $4000 and uses the built-in SP (hardware serial port) that the origional 6522 VIA chips were unable to use because of a design flaw. Both 8-bit data ports ($4000/$4001) are completely unused and the ICT hard drive interface uses these two data ports along with a modded 1571 ROM to talk to an 8-bit XT hard drive card. I don't have the part number for the latest CBM 1571 ROM but funet should give some good info on it... good luck, RadWar From filker@newton.physics.metu.edu.tr Fri Jul 15 09:09:49 1997 Status: RO X-Status: Path: news.metu.edu.tr!news1.usf.edu!atl-news-feed1.bbnplanet.com!news.bbnplanet.com!smartdna!news-xfer.mccc.edu!news.maxwell.syr.edu!howland.erols.net!infeed2.internetmci.com!newsfeed.internetmci.com!news.cmc.net!news.efn.org!not-for-mail From: "Ron C. Hackley & Ruth Hackley" Newsgroups: comp.emulators.cbm,comp.sys.cbm Subject: Re: Where is the DOS chip on the 1571? Date: 15 Jul 1997 09:09:49 GMT Organization: Oregon Public Networking Lines: 28 Message-ID: <01bc90fe$2b1942e0$4e58cbcc@fgm1> References: <33C95BF4.7977@gate.net> NNTP-Posting-Host: jeffnet.org X-Newsreader: Microsoft Internet News 4.70.1161 Xref: news.metu.edu.tr comp.emulators.cbm:16363 comp.sys.cbm:64375 from the "Users Guide" - 6502A microprocessor (2) 65C22A I/O 23256 32K bytes ROM 4016 2K bytes RAM 64HI156/64HI57 Gate Array R/W Hybrid IC Analog Circuit IC (MFM,GCR) -- Ruth Hackley fgm@jeffnet.org fgm@rosenet.org Paul Graber wrote in article <33C95BF4.7977@gate.net>... | Hi, | I am trying to find the DOS chip on my 1571. I have found two chips | which can be pulled off the board, one is small and one is longer, so I | am assuming one of these is it or both. Which is which. And what is the | other one for. | | Any help would be appreciated. | | Thanks | -- | Paul Graber | gedwyn@gate.net | "Ultima Dragon and Classic Gaming enthusiast" |