Re: Help writing a vblank server in assembly

Article View: comp.sys.amiga.tech

Article #11258

Back to comp.sys.amiga.tech Previous Next

#11258

From: Randell Jesup
Date: Mon, 30 Jan 1989 21:30

10 lines
895 bytes

In article <3777@crash.cts.com> billk@pnet01.cts.com (Bill W. Kelly) writes:
>Also, I believe d0-d1/a0-a1 may be used as scratch regs. by library routines.
>(or it may be d0-d3/a0-a1, so be careful...)

	Oh, when writing vblank routines, currently you must not assume the
value of a0 on entry, but MUST set a0 == _custom on exit!  Especially note
this, people writing in C.

-- 
Randell Jesup, Commodore Engineering {uunet|rutgers|allegra}!cbmvax!jesup

Technical Details

Message-ID: <5854@cbmvax.UUCP>

Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!cbmvax!jesup

References: <3777@crash.cts.com>

Show Full Headers

Complete Article Headers

Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!cbmvax!jesup
From: jesup@cbmvax.UUCP (Randell Jesup)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Help writing a vblank server in assembly
Message-ID: <5854@cbmvax.UUCP>
Date: 30 Jan 89 21:30:09 GMT
References: <3777@crash.cts.com>
Reply-To: jesup@cbmvax.UUCP (Randell Jesup)
Organization: Commodore Technology, West Chester, PA
Lines: 10

Reply to Parent Message