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|    alt.os.development    |    Operating system development chatter    |    4,255 messages    |
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|    Message 3,910 of 4,255    |
|    Robert Pengelly to Robert Pengelly    |
|    Re: COM1 interrupt for 16-bit OS    |
|    12 Nov 23 11:13:14    |
      From: robertapengelly@gmail.com              On Sunday, 12 November 2023 at 19:04:55 UTC, Robert Pengelly wrote:       > On Sunday, 12 November 2023 at 15:18:45 UTC, wolfgang kern wrote:        > > On 12/11/2023 15:34, Robert Pengelly wrote:        > > ...        > > >>>> the mouse sends a sequence of bytes where every byte causes in IRQ.        > > >>>> so you first need to fill a buffer with the gotten bytes before you       can        > > >>>> calculate/scale/interpret the values. mouse IRQs can easy come out of        > > >>>> sync, so checking always for the first byte mark is a good idea.        > > >>> Oh I thought you had to get them all at the same time when the       interrupt was fired. As for filling the buffer how would I tell the interrupts       apart? I can test for 0x40 and 0x01 (which I'm already doing) I'm just a       little confused how I would        know whether it's the 1st, 2nd and 3rd bytes.        > > >> there is a mark for the first byte (reread the RBIL I posted)        > > >> I use one variable for count down (easier than count up) and use this        > > >> with BX as an index into my buffer.        > > >> and when the buffer is filled I adjust all my mouse-variables which I        > > >> later use on my mSec timer-base schedule to update cursor and act on        > > >> buttons.        > > > Yeah, there's bit 6 for the initial bit, I weren't sure if there's       anything identifying the others. So basically have two variables one being a       counter and just write to the buffer until I get three (or if it's counting       down then it would be until        I hit zero)?        > > yes.        > > As for:        > > >> I use one variable for count down (easier than count up) and use this        > > >> with BX as an index into my buffer.        > >        > > > How do you use it for the buffer if your counting down? If you were       counting up you could shl by 8 and add that to the buffer offset.        > > no shift required here at all:        > >        > > push ...ds,ax,bx,cx,dx        > > ... ds become ptr to my data        > > IN AL,port        > > TEST AL,0x40        > > jz skip_init        > > xor bx,bx        > > MOV CX,3 ;(or eight in my case)        > > MOV [count],cl        > > MOV [index].bx        > > skip_init:        > > MOV BX,[index]        > > MOV [BX+buffer],AL        > > INC word[index] ;or: INC BX |MOV [index],BX        > > DEC byte[count]        > > pop ... dx,cx,bx        > > MOV AL,0x20        > > out 0xA0,AL        > > jnz done_it        > > got_all:        > > ;store/modify, update only variables, actions are done in idle queue.        > > done_it:        > > pop ax        > > pop ds        > > iret        > > __        > > wolfgang       > Ahh you have 3 variables instead of 2, right I think I understand. What       should I do about the buffer though? Like should I get them in say a 1Ch       handler to move the cursor in there?       That should have been "What should I do about the values though?" Like should       I parse the buffer in say 1Ch and move the cursor in there?              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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