Zorro II and CPU slots on Amiga 500 plus!
Finally! 30th of October 2004

This page has to be considered as a preview, sooner or later I will give to it a better look ;-)

Yesterday, 29th of October, 2004 the European Constitution has been signed and I am not happy at all with this. But today I managed to complete the board I have been building for giving to an A500+ motherboard I own a much faster CPU and the ability of using Zorro II boards: photos should be exhaustive! :-)


The whole thing is far from being completely stable, in particular I will have to "strengthen" the power supply lines of the Zorro II riser card. Also, if I enable 68040 caches, there is some corruption of the display graphics, seen in benchmark programs such as AIBB. I hope I will be able to fix these issues, if possible.

If you are interested, by clicking here you can read a text (in English language) where I wrote something about the history of this design and the various phases of its carrying out. I wrote it because such an article had been asked to me by an online Amiga magazine from Germany, its first issue being available just recently (2nd of March 2005). The magazine is called "BBoAH-MAG" and here is its website.
I hope I will sooner or later be able to translate it into Italian too, and also draw a schematic of the design.

Here are the photographs:

General view. Please note the A4000T keyboard, connected through an adapter cable (reset not working) and the big 5,25" SCSI drive used for the tests

 
From left to right, the G-Force 040 33@40MHz (with the crystal temporarily floating), the A2088 Bridgeboard and an A2091 SCSI controller with 1 MB of RAM
The G-Force 040 installed on my Slot CPU board
There is no cheat, everything is autoconfigured!
With caches enabled, I eat stock A4000s for breakfast with respect to CPU power...
A2088 and A2091 on an A4000 daughterboard...
The busboard removed from A500: the biggest chip is BUSTER, the others are mainly 74LS245 buffers
The back: just few meters of wire wrap cable! :-)
Top view of the A500 with empty busboard