kickstart ROM 3.1 on OCS machine

[satiropan]

I have recently tryied a 3.1 kickstart ROM on my A500/1.3 rev.6a OCS (1MB Agnus) computer.
I have had errors and boot only with 1.3 workbench disk.
Then I have added 512KB on board, adding 4 DIL chips and DIL sockets, with no trapdoor expansion, and the machine would boot with 3.1 workbench but being unstable.
Now I have read on DC-KF500.lha on Aminet:
'Make sure you aren't trying to run Kickstarts later than 37.350 (2.05)with an OCS chipset.'
Is this the reason of my problems?
Has anybody tryied the same?
So it is impossible, let say, to use kickstart 3.1 on a A2000-A which can't be upgraded to ECS due to differences on Agnus socket?
Where to find cheap ECS kit?
Thanx for any advice.
Ciao
S.

[spirantho]

My "Disk Factory" system:

Amiga A1500 (originally OCS 1.3)
Apollo 2030
GVP SCSI card
25MB RAM (16MB on the accelerator, 8MB on the SCSI, 1MB Chip)
And of course Kickstart 3.1 running OS 3.9.

(actually it has tons of other stuff as well like a 486 bridgeboard, but that's all that's pertinent!)

So yes, I'd say it can work.

[satiropan]

But is your machine still OCS?
My A2000A (which can't be upgraded to ECS, being similar to A1000) is now dead for yet unknown reason so I can't test, but on my OCS A500 with 1MB chipram, 3.1 rom doesn't work properly.
Of course it could be the rom chip which has problems, I have no other Amiga around to test it.
Thanx
Ciao
S.

[Piru]

Kickstart 3.1 works fine with OCS (at least if it's the A500/A2000 one).

[satiropan]

So maybe the chip is bad?
Taking off the sticky label on it, I have found it is a AMD chip, AM27C400-120PC.
Of course the pinout must be the same as the MX23C4100, which is the average 3.1 rom chip for A500/2000, otherwise I wouldn't be able to boot, even with instability.
I am wondering whether this AMD chip has some sort of different sensitivity to voltages, kind of I could need to put some capacitor or resistor some where to improve compatibility.
Actually, with the 4 added ram chips, jumper 2 as default (first 512KB as chip and added 512KB as fast) and jumper 7a setted as internal ram (no trapdoor expansion) the 3.1 rom boots normally.
I mean, increased current drain (4 chips more) stabilizes the system?
What do you think?
Thanx
S.