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Archived: SECAM 74LS574 modification instructions.
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Author:  classics [ Thu Apr 14, 2011 11:12 pm ]
Post subject:  Archived: SECAM 74LS574 modification instructions.

Ok, here are the instructions for installing the address latch for those who wish to DIY.

I've tested it with a GAL16V8 but a 74LS574 should work the same. Instructions for using both are included.

1) Cut the traces shown, there are two on the front side just below the IDE connector, and one on the rear.


2) Take the programmed GAL16V8 or 74LS574 and bend up all of the pins except 10 and 20.

Solder this chip in place on top of the 74245 IC on the PC, with only pins 10 and 20 soldered to the IC below.


3) Make the following connections:

E IC -> GND IC (Pin 11 to Pin 10 on GAL16V8, Pin 1 to Pin 10 on 74LS574)

A0 PCB -> A0 IC (Pin 2)
A1 PCB -> A1 IC (Pin 3)
A2 PCB -> A2 IC (Pin 4)

B0 IC -> B0 PCB (At IDE header pin shown, on front PCB)
B1 IC -> B1 PCB (At IDE header pin shown, on front PCB)
B2 IC -> B2 PCB (At IDE header pin shown, on rear PCB)

PCB o2 -> IC o2 (Pin 1 on GAL16V8, Pin 11 on 74LS574)







The equations and JED file for the GAL16V8 are attached.


Author:  classics [ Sat Apr 16, 2011 2:56 am ]
Post subject:  Re: Let's do something constructive about the MyIDE+F stabil

Sysop*Marius wrote:
Two other questions:

1. I also have an original AtariMax 1Mbit Flash card with MyIDE. The one where there is room for the original TTL chips. This board has different layout (as far as I can see that) I can not find the connection pads A0, A1 and A2 on this older (original) board.

2. Will this fix (with that GAL) also work on the original non-flash based MyIDE?

Hi Marius,

Here are the connection points for the older MyIDE+Flash with the TTL chip layouts. I don't have any of the original PCB on hand for real pictures but these are made from the PCB drawings.

Besides the different traces to cut and the different connection points, everything else should be the same.


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