exxos's Atari, Amiga & retro forum

The bus resistors should be changed from 10K (or in some cases 4.7K) to 2.2K values. This is on the address and databus from the CPU. Resistor networks are 9 pin bussed types.

The ST bus is very weak and needs a lower value resistor array to keep the bus stable. Symptoms can be machine not booting when a cartridge is plugged in, or intermittent crashes or screen corruption in general and even some DMA related issues.

I will list motherboards as I work out where the arrays are located. There are so many revisions it may take some time before the list is complete. Currently I am assuming resistor pack numbers are common between ST/F/M & STE Machines.

SEE HERE HOW TO IDENTIFY THE SIL ARRAYS https://www.exxosforum.co.uk/forum/viewt ... =35&t=4730


C070789



C103253


STE (EXTERNAL BLITTER)

NOTE: P100 needs to be 1.2K (if its not already).

Changing bussed Resistor Packs (Arrays) on a Mega 1.

Yellow is address bus and red is data bus. On a Mega 1 the address bus is normally (if not always) 4,7k ohm and the data bus seems to be 10k ohm. Change for 2,2k Ohm.
I've moved this to be in the correct location @DoG

C070523


Thanks @Robson ;)