[Coco] CoCoEPROMPak

Chad H chadbh74 at hotmail.com
Thu Nov 28 12:07:40 EST 2013


Mark , the COCOEPromPak as been working flawlessly thus far.  I finally go
around last night to building a 'test' 32K ROM out of 4 x 8k HDBDOS ROM's
and flashed them into a 27256 32k chip.  I modified the startup message to
show "BANK 1", "BANK 2", etc. depending on the 8k section I had selected by
jumper, but I could only ever get "BANK 1" or "BANK 3".  I wondered what
happened to 2 and 4 and thought I messed up when I soldered but found
nothing wrong in the continuity.  I then went back to your information in
the GitHub project....

4k:
    * Install 2732 at U1
    * JP2, JP3 not used
8k:
    * Install 2764 at U2
    * Set JP2 to 1
    * Set JP3 to 1
16k:
    * Install 27128 at U2
    * Set JP2 to 1
    * Set JP3 to 1
32k:
    * Install 27256 at U2
    * Select 16k bank with JP2
    * Set JP3 to 1
64k:
    * Install 27512 at U2
    * Select 16k banks with JP2 and JP3

If I'm reading this correction, you can only select banks of "16K" and NOT
"8K" with the jumpers as the board is configured?
If this is true, what changes would I have to make to enable "8K" selection?

Thanks!

-----Original Message-----
From: Chad H [mailto:chadbh74 at hotmail.com] 
Sent: Wednesday, October 23, 2013 9:50 PM
To: 'CoCoList for Color Computer Enthusiasts'
Subject: RE: [Coco] Blank EPROM-based Program Pak Board Design Released

I ordered a set of 3 to tinker with when experimenting with ROMS.  Now I
won't have to put so much wear and tear on my CoCoFLASH.

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
Behalf Of Mark J. Blair
Sent: Wednesday, October 23, 2013 1:38 AM
To: CoCoList for Color Computer Enthusiasts
Subject: [Coco] Blank EPROM-based Program Pak Board Design Released

Good news: It's released!

I've tested it with 2732, 2764, 27128 and 27256 EPROMs. Unfortunately, I
don't have any 27512 EPROMs handy to test out, but I'll take a chance and
call it "probably working" anyway.

For more details, including a link to order bare PCBs from the vendor I used
if you're daring enough, see this page:

  http://www.nf6x.net/2013/10/cocoeprompak/

-- 
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/


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