A590 14 Mhz SCSI Mod

[SpeedGeek]

Well my fellow EABer's it's been 5 months since I posted the A2091 version and to the best of my knowledge no A590 owner has done a "Bloody Damn" thing about it! ...and why not? Was a 5 month head start and plenty of hints not enough? Would you rather be a "Slowpoke Rodriguez"?

Oh well, the reason I really wanted A590 owners to do this for themselves was because I don't own an A590 or even an A500. So I can't actually do the mod and say "Been there. Done that". A very special Thanks to AmmoJammo for testing this mod!

Here are a few suggestions in preparation for the mod:

1) First have a good read of the A2091 version here:
http://eab.abime.net/showthread.php?t=58433

2) The 7 MHz clock input to the SCSI chip should be cut as close as possible to Pin 7 of the chip to avoid possibly disconnecting it from DMAC.

3) See tips from AmmoJammo in post #2.

4) If you don't have any fast memory installed on your A590 then see Buzzfuzz's post on the A2091 thread. It does make a difference!

Enjoy!

[SpeedGeek]

The name of this mod has been changed. It is no longer a theoretical mod thanks to AmmoJammo!

Originally Posted by AmmoJammo

In theory, is this correct?

Cut track at U4 pin 7
Wire from U6 pin 11 to U4 pin 7
Cut track at U6 pin 13
Wire from U6 pin 13 to U6 pin 6
Wire from U6 pin 12 to U6 pin 9

thanks.

edit: pulled the board out of my A590, the track that runs to U6, pin 13, is under the IC... not sure where it goes from there, or if it goes anywhere else, so the easiest way would be to cut the leg of the IC ontop of the board