X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f Message-ID: <000e01c44ef4$7d941520$0d01a8c0@josepmariaxp> From: "turomas" To: References: <001701c44ed6$30907d40$0d01a8c0 AT josepmariaxp> <200406101615 DOT 35163 DOT pavenis AT latnet DOT lv> Subject: Re: Troubles with hard interrupts aand HDD Date: Thu, 10 Jun 2004 16:09:05 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-MailScanner-Information: Please contact the ISP for more information X-MailScanner: Found to be clean Reply-To: djgpp AT delorie DOT com I have caugth HDD interrupt and I put there my own interrupt wich calls HDD interrupt. I can see that delay comes when HDD interrupt has finished, and only with smartdrv installed. May be DMA? Now we have began to work with rtlinux. But now I have to solve this problem in dos. > On Thursday 10 June 2004 13:32, turomas wrote: > > I am developing a CNC. I use a hard interrupt every 500 micro seconds. I > > have used Irq9 and Irq0 too. It works fine but when I use HDD the latency > > gets back to 2,5 ms. Can somebody help me. > > Perhaps HDD interrupt handling could take rather much time in DOS or somewhere > interrupts are getting masked for up to 2.5 ms. Also switching between real > and protected mode requires time. > > I myself would try to use some real time operating system for such task (see > for example http://www.rtai.org). > > Andris > >