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Originally posted by Stolistic on 7/13/2008:

I got to thinking the other day about how hard it is to find replacements for the color PROM on the PE+ and decided to mock up a little adapter using a UV EPROM instead.  The advantage would be being able to program them in a basic model programmer, since color PROMs generally require special adapters and high voltages.

One of the challenges with this project is that color PROMs have an access time near 60ns, and most EPROMs today are 250ns or higher.  After a bit of searching I found some fairly cheap EEPROMs on JAMECO that have an access time of 45ns.  They are M27C512-45XF1 and run about $2.35 each.  They are a bit overkill in memory size, but the price is right.

So I ordered a few and some 28-pin and 20-pin sockets to go with them.

All that was required next was to map the pins from the EPROM to the color PROM, and solder it together on a piece of perfboard.  The 28-pin socket goes on the top, and the 20-pin socket goes on the bottom (with wires soldered through the board to connect to the bottom layer).

Below are some pictures of the final adapter installed and working in my PE+ machine. (Pictures pending at this time.)

I drafted a PCB layout and may consider making a bunch sometime, but for now my prototype is enough.

I saw someone post something like this on the old site. They used a 27c256 or 27c512.

Given the small size of the prom theoretically you could dump a number of these into a 27c512 and make it dipswitch selectable.

I gave credit - I was re-posting this for the sake of preserving the information, not to steal someone else's work.  :)  I'm actually in communication with Stolistic right now to try and get the pictures he posted.



In fact, you posted that on the old thread.   :71-

Can't find my old pics, but made a new picture of the most important part below:

(http://www.stolistic.com/slots/adapter.png)

I'll snap a photo of the completed adapter sometime and update this page.

Nice!  Thanks for posting, Stolistic!

Now the hard part..... getting the data off the old bi-polar proms.....

Pretty sure you could swap the sockets and put the thin CAP socket on top, and wide eprom pins on the bottom and read it in with a standard burner as a 27c512 and truncate off the excess data.  The mapping of the pinout would remain the same, just the placement of the sockets would change.

That makes some sense but I thought there were dual voltages required to operate the older chips. Other wise why would my burner not simply support the chip via an adapter like they do others.

The dual voltages generally refer to the fact that burning the chip requires a different voltage than reading it.  Reading takes much less voltage, so if you just want to read the chip, you should be fine.  I put my CAP in a breadboard and read it fine with a 5V regulator tied to the pins to light up some LEDs.  I'll probably build an equivalent adapter and try it out sometime in the near future.

I built a crude example this afternoon to test my theory. 

Its ugly but it works.  After you read the CAP in, you need to trim everything starting at 0x200 to the end of the file, so all you have is 0x000 through 0x1ff.

If you are reading in a normal CAP you have to interlace a row of 32 0xFF's every other row starting at 0x020 and ending on row 0x1e0.  I didn't read in a superboard prom (CAPX) but assume you would leave the data as is, making sure rows 0x100 to the end of file is all 0xFFs or all 0x00s.

Pictures are below:
(http://www.stolistic.com/slots/cap1.png)
(http://www.stolistic.com/slots/cap2.png)

Sweet, I like the adapter to read the PROM's.  Looks like I need to make a run to RatShack and/or HSC this weekend.

Confused on the rest of it though.  On a regular CAP, after reading it with the adapter you install 2 rows of 0x00 to extend the data to restart at 0x40 for 2 rows and then 2 rows of 0x00 at 0x60, 2 rows of date at 0x80, etc ?  This is necc. to make it read correctly once burnt onto a 27c512?

000: DA TA DA TA DA TA DA TA DA TA DA TA DA TA DA TA
010: DA TA DA TA DA TA DA TA DA TA DA TA DA TA DA TA
020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
040: DA TA DA TA DA TA DA TA DA TA DA TA DA TA DA TA
050: DA TA DA TA DA TA DA TA DA TA DA TA DA TA DA TA
060: 00 00 00 .............................. . . ... . ..

Also, this process is not necc. for a CAPX and the data ends at 0x0ff ??

Just trying to get my few remaining brain cells around this.
 :5-   :47-   :5-

Yes, you got the concept.

CAP Data after reading it in:
0000: 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01
0020: 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02
0040: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03
0060: 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04
...etc...

CAP Data after editing:
0000: 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01
0020: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0040: 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02
0060: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
0080: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03
00A0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
00C0: 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04 04
00E0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
...etc...

I have not read in a CAPX (superboard) yet, so cannot confirm, but from what I've seen, it appears you just leave the data alone.

Have fun soldering and be sure to test all your connections for breaks and continuity before you use it.  Post a pic if you get it working.

** UPDATE **

I tested the adapter with a CapX chip and with a normal Cap and things work just great.  However, my initial discussion about the non-CapX chips needing the data interlaced with FFs is INCORRECT.  The data read in is in the proper order.  So the reader works the same for both CAP and CAPX chips.  No need to make edits afterwards.

-------------------------------------
On that note:

I'm going to be sending the design off for PCB manufacturing, and would like to get a count of people interested in purchasing a board or two.  Depending on the results, the price will be lower.  But an initial estimate puts them in the range of $10-$12 each for a small quantity.

So if interested, either plop a reply here or send a pm.  Be sure to note what type of adapter you would like and quantity.  Remember the pcb design allows for either a cap reader or a cap replacement.

Example request:
Qty 1 - CAP Reader Adapter
Qty 3 - EPROM to CAP Adapter

I'd like to order before month-end so please reply if you think you may be interested.  Just trying to get a ballpark idea of the batch size.

Thanks!

Please sign me up for 1 Cap to Eprom adapter.

Sign me up for:

Reader = Qty. 1
Adapter = Qty. 2

Saves me the time of rounding up parts and assembly.   :3-

FWIW, Jameco current catalog shows single unit M27c512-45xF1 at $2.65, 10+ at 2.39 and 100+ at 2.12 each.

Just to clarify, it will include all the sockets and be assembled and tested, but you will need to purchase your own EPROMS.

I'm in for:

Reader = Qty. 1
Adapter = Qty. 2

Thanks!

Please put me down for 2 EPROM to CAP adapters.

Small bump to see if anyone else is interested in ordering some reader or adapter boards.  I'll probably work on placing an order by end of the week and let everyone know when they are available.  I'll be adding extra quantities onto the order in case someone inquires later.

Thanks!

I'm in for One of each (Reader and Adapter) also.

Thanks!

Sorry for the delay, I'm in for one of each also! Cool stuff! :)

What ever became of this project? Did these boards ever get produced?

Thanks,

I'm in for one of each.  :200- :96- :97- :97- :97-
2nutz, you can go to HSC, just stay away from my retail stash of Molex connectors. :208- :208- :208- :208-

If it's not too late, I'm in for:

Qty 2 - EPROM to CAP Adapter

Thanks,
Eric

I am still in for 2.

Looks interesting...

Stolistic:  if they are still available PM me to sort out how I'll send you the money to get one of each shipped to my actual address (01 reader + 01 adapter)

Best regards

OK, it's been a while since I looked at this.  The circuit layout was on a different computer, and I'm not sure if I lost it or not, but may have to recreate it.

I tested the old design on a non-superboard, and will need to confirm the settings on a superboard.  I know sets like the multi-poker have a larger cap chip and I have to make sure it will be ok with those too (of create a new circuit).

So I'll try to get back on this and let everyone know the results (again).

Thanks

Cool... K+ for the good work on PE+ (as usual)    Let me know when you're ready ;)

Cheers

I'm still in, as you know.  :)

If anyone has any extras, may I get one?
I'd like to play with the dip switchable one.

I wonder if anybody has gotten this board to work, when I create my own schematic in Eagle Cad, I come out with a different layout.  Is there something I am missing?

Here is the layout I came up with:

(http://www.fluffyshihtzu.com/webimages/capprom.jpg)

I would like to know before I go to all the work and make a junk board.

Scott

You schematic looks correct.  I can see a mistake on mine what A5-A8 are shifted.  The actual prototype I have does not have them shifted.  It is just a translation problem to the schematic, which I believe I updated in a later revision.  Good catch!

Thanks for the quick response, I was going nuts when what I thought was right could be wrong!  As they say, measure twice, cut once!

I am new into this stuff, figured the problem may have just been me and my lack of experience.  I picked up a copy of Eagle Cad software and started learning the program.  From what I see it is possible to make the unit support many different CAP PROMS if a few jumpers were to be added. Pins A9..A15 can all have jumpers.  For instance if we place a tri-state jumper on A9 and ground A10 through A15, this should offset the memory by 512K.  By changing the jumper on A9, back to ground, the unit should read the first CAP Prom's memory location.   Here is a quick example of what I am thinking explained a different way.

Cap Prom #    A9             A10           A11                 Offset
     0                GND          GND           GND                0
     1                5V             GND           GND                512K
     2                GND          5V              GND                1024K
     3                5V             5v              GND                1536K
     4                GND          GND           5V                   2048K
     5                5V             GND           5V                   2560K
     6                GND          5V              5V                   3072K
     7                5V             5V              5V                   3584K

 We could have many more CAP Proms on a single 512K chip if we placed more tri-state jumpers on the board, many more than proms than is on the market!

Note: I am pretty new at this so I could be wrong so don't take what I post as gospel concerning this information.

Scott

HOLY ROLLER ... I DID IT!!   :267- :267- :267- :267- :267-

I am in total gratitude for this completely awesome post!

 :131- :131- :131- :131- :131-

I never imagined I could actually solder a circuit board, but after a little practice, checking it a gazillion times, I did it!  In my continuity check, I found one connection that crossed, but that's because the wires got a little hot and joined, but as soon as I separated them, all was good.

I LOVE IT!  I LOVE IT!  I LOVE IT!
THANK YOU!!  THANK YOU!!  THANK YOU!!

Had to add pictures!  I put a ziff socket on top to make it easier to change chips.  Hope that's safe!  (And yes, I plan to label the chip ;-)

Wow, nice job!!

That really cool!  :133-

Great job with that!  :89-
Those low-profile ZIF sockets are the best!

And now I've got the reader too ... did that one in just a few hours!

This is such as awesome site and post!   :131-

Now I just can't wait for Kevin Knagl or Neon Kiss to figure out the CGA to LCD PE+ conversion!   :89- :89- :89-

Dave  Send a PM to CerTech ( Troy ) and ask  any questions you have on a monitor.  Troy is the tech at Ceronix's and has been for close to 20 years, and one real nice guy.  If a PM fails let me know I'm pretty sure I have his phone number.

First off emm386, your doing a great job! 

I used your drawing to just bite the bullet and make a PCB for the adapter.  I used ExpressPCB mini board service.  Kind of over kill since what you did works just fine, but I wanted to try something I have never done before.

I now have some extra boards so if anybody is interested in one let me know, you can have it at cost.  knagl, with as much help as you give everyone on this site I would be happy to just give you one.

Unfortuantly I didn't see the post about adding jumpers to store multiple caps on one 27c512. that would have been great to add that, maybe next time.

K+ and an excellent offer, thank you.   :89-  I'll send you a PM as I'm actually interested in a few of them.

Just in case anyone wanted to know how the boards I made look.
I have just a few more if anyone wants one.

You mean like this,

2Nutz,
Nice setup...  :244- :3- :244-
Someone had posted one of those before and they look great. Did you make these? or just the proud owner of one. :96-

That rig looks like the way to go. If your not selling them could you post the pinout.
If you are selling them could you please send me a PM with your price.

Thank you....
and K+

I wish I had some of these.

Just posting some pics I had since there seems to be some interest/activity in being able to have CAP's available.

  :89-

Do you own the one you posted the picture of?
If so, with a few more photos we might be able to get the pinout of how it's made.

 :99- I've tried the adapter, but somehow I fail, I program the 27C512 with the original file 707, and does not work well, progress achieved by connecting pins 18 and 20 of the 27C512 ground, but just does not look right play, letters appear colorless. could give me some advice? I made the adapter along the plane published here and rectify the connections A0-A7, Q0-Q7, the A8-A15 are grounded, like the plane. help!  :99- :99- :99-

see the picture

I have found the problem, I had not noticed I was using a CPU 340, and change the CPU and the game looks good.

Nice job, congrats on getting it working.

Forgive my ignorance, but what is a CPU 340?

I know here in Colombia and three types of CPU 300, 320 and 340, each with differences between them, but used to deserts types of games, the CPU 340 is the one you call superboard.

I have the file color prom 320 for a cpu that does not work on a 340 cpu, besides that the prom is a different color reference.