Search found 6 matches

by gacaffe
Sun Dec 11, 2016 1:47 pm
Forum: Hints and Tips
Topic: FS and HS interrupt flags
Replies: 11
Views: 10871

Re: FS and HS interrupt flags

Simon, thanks a lot.

I will post soon.

Gabriel
by gacaffe
Sat Dec 10, 2016 12:45 pm
Forum: Hints and Tips
Topic: FS and HS interrupt flags
Replies: 11
Views: 10871

Re: FS and HS interrupt flags

Amazing stuff Simon. Hi Gabriel.... you can do it another way if you want to..... if you know what frequency the noteplayer has to be serviced at, then you can interleave some jsr's into your code at regular intervals... i do just that in this demo: https://www.youtube.com/watch?v=prkZSet3MbM this i...
by gacaffe
Fri Dec 09, 2016 6:59 pm
Forum: Hints and Tips
Topic: FS and HS interrupt flags
Replies: 11
Views: 10871

Re: FS and HS interrupt flags

Thank you Simon, I am concerned about your comment on polling instead of using an ISR. the costs of a vectored irq are prohibitive as the 6809 stacks all the registers... thus a polled irq (using the flags at $ff01/03) is alot cheaper... (just remember to ACK) the irq (lda$ff00/$ff02) or else they w...
by gacaffe
Sun Dec 04, 2016 5:22 pm
Forum: Hints and Tips
Topic: FS and HS interrupt flags
Replies: 11
Views: 10871

Re: FS and HS interrupt flags

Re the HS being flagged even when disabled: food for thought; this could be a bug in XRoar. The interrupt received line of the control register is always updated in the PIA code, even if the IRQ isn't signalled to the CPU. It's been that way (bar a brief period from about July 2005, where it was re...
by gacaffe
Sun Dec 04, 2016 11:43 am
Forum: Hints and Tips
Topic: FS and HS interrupt flags
Replies: 11
Views: 10871

Re: FS and HS interrupt flags

Thanks robcfg! It's a bit worrying that the video timing changes from board to board. Anyway, I think I forgot to mention some important points: 1. I am using Xroar to do the test. I do have a Dragon 64 (made in Wales), so at some point I will test the code in this machine. 2. What I need is the fol...
by gacaffe
Fri Dec 02, 2016 11:29 pm
Forum: Hints and Tips
Topic: FS and HS interrupt flags
Replies: 11
Views: 10871

FS and HS interrupt flags

Hi guys, I am writing a test routine to increase two counters. Counter CHS is increased with the HS interrupt (falling edge) and the other counter (CFS) with the FS interrupt (rising edge). First, I set the interrupts: ORCC #$10 ; Disable IRQ ; set hsync interrupt ;set bit 0 of P0CRB (enable FS IRQs...