SGI Personal Iris 4D/35

John Ball ball.of.john at
Mon Feb 11 19:02:35 CST 2019

Hey Kyle.
You can narrow things down a bit by removing the optional Z-buffer and
additional bitplane memory (ZB3 and BP4). While that removes those two
masses of memory out of the equation that still leaves the still massive
amount of ZIPP base video memory. for the later Onyx systems I've only seen
pinstriping when the video memory or supporting glue has been allowed to
overheat. I can't recall if it tests the graphics as well but have you tried
running the ide diagnostics in case that refines the error a little?


>I've got a graphics issue in my 4D/35, and I suspect it's a VRAM chip. I've
>got vertical lines appearing on the screen, but not everywhere on the
>screen; that seems to hint at an issue with one buffer having bad memory.
>It was especially evident in the flight simulator demo, where alternating
>frames flashed with and without lines.
>The ever helpful self test says, "ERROR: Failure detected in the
>Electronics Module (graphics). press <Enter> to continue".
>The system is equipped with the ZB3 and BP4 on a GR1.2.
>How can I better diagnose this issue? There are so many RAM chips soldered
>on these three boards. Tracking it down to a single chip sure would be

More information about the cctalk mailing list