Progressive Peripherals & Software (PP&S) A2000/040 overclock

[wmaciv]

Is there any data on the importance of refresh rates for this card?  I am currently using two chip, 60ns rated 4MB SIMMS, 4K refresh from what I can tell.  Is there any speed or stability advantage of going to a 1K / 2K refresh SIMM with this hardware?  Nothing in the user manual makes any distinction about refresh rates.  I am asking because the PP&S memory autoconfig function only works to configure memory within the Zorro II address range; all other memory is added via an "AddMem" type utility at boot time.  This auto config function stops working above about 37 Mhz, but if I boot with the autoconfig disabled, I can easily boot at 40mHz and maybe above.  I have an L88M mask 40 MHz rated 040 that runs cool in use at these frequencies.  Something in the auto config circuitry or bus does not like the higher clock frequencies at boot time.  What is the limiting factor here?  Thanks for any help you can provide.

Mac

[Whaka]

Hi,
with a 040, and 60ns ram, you have a lot lot of room.
in your case, the problem is clearly not the ram itself.
there's a lot of gal/pal on this card, and some certainely start to fail when you're near 40 Mhz.