PowerMac 8100 Booting issues

nottomhanks

Tinkerer
Oct 31, 2021
118
51
28
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
 

Mr. Fahrenheit

Tinkerer
Founder
Sep 2, 2021
141
230
43
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

Tinkerer
Oct 31, 2021
118
51
28
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

Tinkerer
Oct 17, 2021
77
118
33
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.
 
  • Like
Reactions: nottomhanks

JustG

New Tinkerer
Dec 12, 2021
50
7
8
California
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.
 
  • Like
Reactions: RetroTheory

RetroTheory

Tinkerer
Oct 17, 2021
77
118
33
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

Tinkerer
Oct 31, 2021
118
51
28
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

Moderator
Staff member
Mar 18, 2022
85
61
18
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.
 

nottomhanks

Tinkerer
Oct 31, 2021
118
51
28
Just following up on this TWO YEARS LATER. I had my friend @ComputerCompulsive take a look at this over the past few weeks, and he figured out that the L2 Cache was bad, and it wouldn't post if it was installed. He removed it, and then got it to boot. I was over there this morning and we did some extensive testing with two logic boards, two G3 accelerators, AND two HPV cards!! Will post YouTube links soon.
 

Attachments

  • 8100:110 G3 300 Intro.MOV
    21.5 MB · Views: 0
  • Like
Reactions: ComputerCompulsive
Nov 27, 2022
95
45
18
Just following up on this TWO YEARS LATER. I had my friend @ComputerCompulsive take a look at this over the past few weeks, and he figured out that the L2 Cache was bad, and it wouldn't post if it was installed. He removed it, and then got it to boot. I was over there this morning and we did some extensive testing with two logic boards, two G3 accelerators, AND two HPV cards!! Will post YouTube links soon.
I did a recap too ;) should be good for a while
 
  • Like
Reactions: nottomhanks