English Amiga Board - View Single Post - A-590 questions ( ROMs, power, HD limits, etc. )

patrik · 09 April 2006, 19:59

Atleast with the adaptor for the GVP GuruROM, there is a GAL mounted under the EPROM which acts as a bank-switcher, to enable the GuruROM to be larger than the 16kB ROM-size the GVP cards supports.

The switcher works so that on a read, when A13-A5 all are zeroes, it will set A15:A14 on the EPROM to what A1:A0 is. This enables the EPROM to be 64kB (four 16kB banks), but if I dont remember wrong, the GuruROM only utilizes the two first banks - ie it is 32kB large.

I suspect the A590-adaptor is similar, but I dont know if they are interchangable.

09 April 2006, 19:59	#12
patrik Registered User Join Date: Jan 2005 Location: Umeå Age: 43 Posts: 926	Atleast with the adaptor for the GVP GuruROM, there is a GAL mounted under the EPROM which acts as a bank-switcher, to enable the GuruROM to be larger than the 16kB ROM-size the GVP cards supports. The switcher works so that on a read, when A13-A5 all are zeroes, it will set A15:A14 on the EPROM to what A1:A0 is. This enables the EPROM to be 64kB (four 16kB banks), but if I dont remember wrong, the GuruROM only utilizes the two first banks - ie it is 32kB large. I suspect the A590-adaptor is similar, but I dont know if they are interchangable. Last edited by patrik; 10 April 2006 at 21:42.