That's what I partially assumed. The problem is that this function in turn calls the kernal routines CHKOUT and BSOUT. I am trying to work out the code path from the user code to the serial handler itself witinn the NMI handler. For example, if a keyboard character is detected (that calls ser_put within keyboard.c) and an incoming serial character arrives at the same time (resulting in another call of ser_put from io.c) will they interfere with each other? If the NMI handler is already processing a transmit character, and an XOFF/XON is required before the previous character has been transmitted, will this cause problems? This is my current thinking. Dave On Sunday, 1 July 2018, Thom Cherryhomes <thom.cherryhomes@gmail.com> wrote: > The ser_kernel ultimately jumps to this: > https://github.com/nanoflite/c64-up2400-cc65/blob/master/dri > ver/c64-up2400.s#L163 > > -Thom > > > > On Sun, Jul 1, 2018 at 1:03 PM David Roberts <daver21145@gmail.com> wrote: > >> Where is the source code for ser_put()? >> >> Dave >> >> >> On Sunday, 1 July 2018, <groepaz@gmx.net> wrote: >> >>> uh, its like 5 lines of code. thats kinda the point - take your plato >>> stuff >>> out of the equation and test *only* the rs232 driver. when this works, >>> then >>> the problem is in your code, not the driver. (i'd even test against some >>> terminal program on the other end, not the plato server - because who >>> knows) >>> >>> >>> Am Sonntag, 1. Juli 2018, 19:46:17 CEST schrieb Thom Cherryhomes: >>> > 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/oliverschmi >>> dt/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. >>> >>> >>> -- >>> >>> http://hitmen.eu http://ar.pokefinder.org >>> http://vice-emu.sourceforge.net http://magicdisk.untergrund.net >>> >>> Wer im Glashaus sitzt hat immer frische Gurken. >>> >>> >>> >>> >>> >>>Received on 2018-07-01 22:00:04
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