[Coco] 24Pin to 28Pin EPROM Adapter PCB for sale

Chad H chadbh74 at hotmail.com
Sat Feb 7 14:44:26 EST 2015


With my recent acquisition and ongoing restoration attempt of a FD-500
controller, one of the things I wanted to do was get the 24-pin ROM out and
put in an adapter for 28-PIN EPROMS (2764, 27128, 27256 & 25512).  I took a
look around the web and at the Cloud-9 unit but honestly they were all a bit
pricy for me and didn't give me easy access to the A13, A14 and A15 lines
like I want because eventually I will be installing switches on the case to
allow me to power down and switch ROM's quicker.

 

So. I designed my own PCB's and just tested one with the controller.  You
can see pictures here .

http://tinyurl.com/m8992jh

 

The boards have header/wire access points for:  VCC, GND, A13, A14, A15 to
make it easier to wire up switches.

 

The FD-502 controller pictured has a single green wire running from the A13
pin to the cartridge connector to allow the 16K rom to work properly and it
has been very stable.  I will be adding switches for the A14 and A15 lines
so I will be able to put 4 x 16K ROM's on a 27512 and have pretty much all
my standard ROMs in one place, which I did on a EPROM adapter but not on
floppy controller yet.

 

Anyways, I only really needed one of the PCB's so I have 2 extra if anyone
is interested.



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