...and I have spent, a week, trying every XON/XOFF threshold value I can think of, it doesn't make much of a difference in the output. Greg King suggested this, as well. -Thom On Sun, Jul 1, 2018 at 12:46 PM Thom Cherryhomes <thom.cherryhomes@gmail.com> wrote: > there is no simple text mode in PLATO. can't do that. > > -Thom > > On Sun, Jul 1, 2018 at 12:43 PM <groepaz@gmx.net> wrote: > >> i'd try those routines with a very simple text terminal implementation >> first, >> and see if the flow control works right. XON/OFF is always a bit tricky, >> so it >> might just be the thresholds that need tweaking. >> >> Am Sonntag, 1. Juli 2018, 19:32:04 CEST schrieb Thom Cherryhomes: >> > great, now if only I can figure out wtf to do... I'm not a skilled C64 >> > programmer, am only passing through to write this terminal. >> > >> > -Thom >> > >> > On Sun, Jul 1, 2018 at 12:30 PM David Roberts <daver21145@gmail.com> >> wrote: >> > > I have never used cc65 - but I know programmers who have been caught >> out >> > > on other platforms. >> > > >> > > NMI routines need to make sure that all CPU registers are >> saved/restored >> > > and that data structures remain intact. If the NMI routine changes >> > > anything >> > > that is relied on outside of it (without the appropriate protection) >> you >> > > are in trouble... >> > > >> > > Interrupts can be inhibited during critical processing outside of the >> > > interrupt service routine. An NMI requires special treatment. We use >> NMI >> > > as >> > > a critical error and real-time clock handler (in preference to an >> > > interrupt) in a piece of communications hardware we use; but the >> hardware >> > > contains a mechanism for (very briefly) disabling the NMI around very >> > > critical data structures that absolutely must not be modified should a >> > > critical error (such as a bus timeout on the MULTIBUS) occur. >> > > >> > > Not sure how much of this is relevant to your problem, but it fits the >> > > symptoms you have... >> > > >> > > Dave >> > > >> > > On Sunday, 1 July 2018, Thom Cherryhomes <thom.cherryhomes@gmail.com> >> > > >> > > wrote: >> > >> The up2400 routines use the NMI to do all the shifting and filling >> of the >> > >> buffers. >> > >> >> > >> I'm not entirely sure volatile has any meaningful consequence in >> cc65. >> > >> >> > >> -Thom >> > >> >> > >> On Sun, Jul 1, 2018 at 11:54 AM David Roberts <daver21145@gmail.com> >> > >> >> > >> wrote: >> > >>> I have only just had a cursory look at the sources, but does >> anything >> > >>> use interrupts? Usually interrupts cause unexpected results. >> > >>> >> > >>> The other thing to be wary of (with C code) is the ability of the >> > >>> hardware to change stuff 'under' the compiler's feet... If C code is >> > >>> mapped >> > >>> onto hardware anywhere - you need to use the 'volatile' keyword to >> force >> > >>> the compiler to re-read the data before use as opposed to using its >> own >> > >>> cached value. >> > >>> >> > >>> Just a couple of thoughts... >> > >>> >> > >>> Dave >> > >>> >> > >>> >> > >>> On Sunday, 1 July 2018, Thom Cherryhomes < >> thom.cherryhomes@gmail.com> >> > >>> >> > >>> wrote: >> > >>>> Hello, everyone. >> > >>>> >> > >>>> My name is Thom Cherryhomes, and I am both the systems operator of >> > >>>> IRATA.ONLINE, and developing a series of terminal programs for >> > >>>> different >> > >>>> machines that can connect to the currently running PLATO systems en >> > >>>> extant: >> > >>>> IRATA.ONLINE, and CYBER1.ORG. >> > >>>> >> > >>>> I've gotten the vast majority of the terminal written, using CC65, >> and >> > >>>> appropriating some bits of code from other places, namely: >> > >>>> >> > >>>> * up2400 for cc65 based on George Hug's user-port 2400 driver. >> > >>>> https://github.com/nanoflite/c64-up2400-cc65 >> > >>>> >> > >>>> * The swiftlink driver for cc65: >> > >>>> >> https://github.com/gilligan/snesdev/blob/master/tools/cc65-2.13.2/libsr >> > >>>> c/c64/c64-swlink.s >> > >>>> >> > >>>> * ip65 for ethernet support https://github.com/oliverschmidt/ip65 >> > >>>> >> > >>>> As I said, the terminal is mostly functioning, but I am having >> problems >> > >>>> when flow control needs to assert itself, The type of flow control >> that >> > >>>> PLATO supports is XON/XOFF, so I've implemented a threshold model >> that >> > >>>> sends XON/XOFF based on threshold values: >> > >>>> https://github.com/tschak909/platoterm64/blob/master/src/io.c#L20 >> > >>>> >> > >>>> #define XOFF_THRESHOLD 250 >> > >>>> #define XON_THRESHOLD 100 >> > >>>> And this is asserted during the io_recv_serial() which gets called >> > >>>> every pass through the main loop: >> > >>>> https://github.com/tschak909/platoterm64/blob/master/src/io.c#L20 >> > >>>> >> > >>>> I understand that the code as is only works with user-port devices >> > >>>> (because up2400 re-uses the kernal structures), these are the >> devices >> > >>>> that >> > >>>> need it most, and I am trying to get these devices working, before >> I >> > >>>> refine >> > >>>> things for the swiftlink cartridge. >> > >>>> >> > >>>> However, what happens, is something like this: >> > >>>> https://www.youtube.com/watch?v=K9VgIigaJzw >> > >>>> >> > >>>> and this: >> > >>>> https://www.youtube.com/watch?v=xjSlCOPXYRk >> > >>>> >> > >>>> I'm not entirely sure what's happening here, as the buffer is >> filling >> > >>>> up, and draining, and the amount of glitching is directly >> proportional >> > >>>> to >> > >>>> the tiniest bits of changes in my drawing routines. The one biggest >> > >>>> cause >> > >>>> of glitch is the block erase routine (which given a set of pixel >> > >>>> coordinates, erases an area of the screen...the cc65 implementation >> > >>>> draws >> > >>>> horizontal lines until the bottom of the bounding box is >> reached... I >> > >>>> would >> > >>>> think this would simply cause the buffer to fill up, which would >> cause >> > >>>> xoff >> > >>>> to trip, stuff would stop being sent, and the buffer would >> subsequently >> > >>>> be >> > >>>> drained until the buffer is empty...but something very subtly >> wrong is >> > >>>> happening. >> > >>>> >> > >>>> I have already spent days messing with the threshold values, as >> well as >> > >>>> trying to shuffle code around to try and alleviate the problem, >> but I >> > >>>> seem >> > >>>> to just keep getting the short end of the stick on this one. >> > >>>> >> > >>>> Could really use some help, any insights? >> > >>>> >> > >>>> Code is here btw: http://github.com/tschak909/platoterm64 >> > >>>> >> > >>>> -Thom >> >> >> -- >> >> http://hitmen.eu http://ar.pokefinder.org >> http://vice-emu.sourceforge.net http://magicdisk.untergrund.net >> >> Habe ich schon erwähnt, daß mir HDTV/Blueray/HD-DVD völlig am >> Allerwertesten >> vorbeigehen? Das derzeitige Programm noch hochauflösender zu sehen, >> empfinde >> ich als Drohung. >> >> >> >> >> >>Received on 2018-07-01 20:02:40
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