PowerMac 8100 Booting issues

[nottomhanks]

Hello there!

I just picked up an 8100/100, and it chimes when you boot, (actually it powers up when you plug the IEC cable in, which is interesting).

Do you have to have the HPV video connector to see video, or will it jump to the next available video card?

I tried resetting the PRAM, but it wouldn't work.

Please help if you can.

Craig

 

[RetroTheory]

Have you tried resetting after powerup?

if the battery is flat or not present you just get black screen after bong, so the reset is necessary if the machine was off for a length of time.

See here:

https://twitter.com/i/web/status/1510977014714490885

 

[Mr. Fahrenheit]

The 6100, 7100, and 8100 series require a good PRAM battery on-board to display any video.

The instant power-on you experienced could be the power button on the rear rotated into the “always on” position.

 

[nottomhanks]

Ah. Those are helpful tips. Will the video show up on the DB 15 connectors on the Nubus Video card, or will it try to go to the HPV first??

 

[RetroTheory]

The mac has sense pins on its monitor connections, it knows there is nothing there so will initialise nubus if monitors is connected there. HPV is not required.

 

[JustG]

I may be incorrect but I remember reading somewhere that 7100 and 8100 systems need to have a card in the PDS slot otherwise the computer may not boot or can crash.

 

[RetroTheory]

You are quite right, That's what it says in the Service source, i have not encountered an issue in real live though. Currently running my 8100/100 without a video card or terminator, that the link above shows my one going to flashing floppy as such.

 

[nottomhanks]

The weird thing about this machine is that the bezel says 8100/100 but the logic board says “Flagship 110 Mhz”. Plus it has the NewerTech G3/300 card installed. Is this a rare logic board or something?

 

[bakkus]

The weird thing about this machine is that the bezel says 8100/100 but the logic board says “Flagship 110 Mhz”. Plus it has the NewerTech G3/300 card installed. Is this a rare logic board or something?

The NewerTech is a cool addon, but could be one source of issues.
Did you try booting with the G3 removed?

There was a 110MHz model released late 1994.