EII can´t boot from the disk

[dr.c]

Yes, I did know, but I have never seen an EII with only two rows of rams fitted, and two empty !

[Elmbeatz]

Ah, I see.

[Jim Stout]

Well no luck, I sit broken hearted 

I guess the only thing I can do is see if I can find another one for parts and make it a project.

Thanks for all your help!

[dr.c]

I cant believe this shit... can you leave only one floppy reader connected ?

WITHOUT floppy disk into the readers, does it seek slowly, really slowly, is it is brlink fast ?

[Jim Stout]

everything lights up the drive is spinning.

But the drive is not seeking or trying to read anything, it just spins.... like record... round and round...

sorry couldn't help it 

[dr.c]

Wait.....

[dr.c]

Okay, go to :
http://cjoint.com/?hbwDzgDrSK

Have you got the tech manual ? The related pages are 7-14 and 7-15. You should sneak around the Z80 SIO2 and PIO; I had as well some trouble with the LS07, they are the ones driving the floppy readers.

Thake them off and put them back, or change them, they cost peanuts (50ç)

[Chaztech]

The very first set of ram chips must work to store the very first sequence of disk software.
segment one! or the boot progress just holds. if you can swap the chips in the first bank to the second bank 8 chips. then try! they are ic12 to ic20 on EII's MT4264-15 chips.
I used a memory test diskette and found this problem and was able to fix it that way.
I used the first slot to test each chip individually to isolate the bad ones even the test disk will hold if the first cells of the ram are bad. hope this helps!

[Chaztech]

made a mistake! IC13 not 12 don't swap 12 out just IC13 to 20 and using the next bank of chips IC32 to 39

[Chaztech]

I was looking at this tread again and realize that those chips in the first position need to be there IC13 to 20. i know this is a unit without a piggy back board but i did a lot of testing on this and think it really needs the first set of them to run boot. i don't think its the A and B areas you indicated. but it uses the first set ic13 to ic20. i took all other chips out and it booted up with 8 good IC's. Of course i may be wrong and the units without piggy back boards had a different structure so forgive me. but whats the harm in trying. Could it be possible someone took out the first set before you got it?