[stella] Syncing without WSYNC

Subject: [stella] Syncing without WSYNC
From: "B. Watson" <atari@xxxxxxxxxxxxxx>
Date: Thu, 30 Aug 2001 10:42:47 -0400 (EDT)
Hi everybody

Does anyone know, is one scanline *exactly* 76 cycles? I.E. if I write a
scanline loop with no STA WSYNC in it, that takes exactly 76 cycles (with
dey;bne start_of_loop as the last 5 cycles), will the Atari stay in sync
with the TV picture, or are the WSYNCs absolutely necessary? The emulators
all handle it fine, but will a real Atari be able to do this?

I saw some code in the Freeway disassembly that does this (with a comment
saying `TV is already on next scanline, no need for WSYNC'), but he only
does it for one scanline. I'm trying to do it for 8 or so.

Pretty soon, I'll be able to stop asking questions like this, my roommate
is a hardware hacker and just bought a bunch of 2732 EPROMs, and is in the
process of building his own EPROM burner (I wouldn't!)



If a trainstation is the place where trains stop, what is a workstation?

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