Making PC Engine HuCards

[pbj]

We all knew where this was going.  You start with a PC Engine Duo and a $30 flashcard.  The flashcard can play the entire library, no exceptions, and loads games in less than 10 seconds unless it's SF2.  SF2... I dunno.. 30 seconds?

Anyway...

First you start trying to buy SF2 to go along with your joystick.  Gotta have at least ONE legit HuCard.  Feels like the right thing to do.  And you notice you can't get one for any less than stupid money on Ebay.  So then you decide to wrestle with Yahoo Auctions Japan again.  This round, I used Jauce.  Unlike Buyee, Jauce will operate on good faith after your initial deposit and let you settle things up once they calculate shipping fees.  Buyee will automatically debit whatever the ---fudgesicle--- they want from your bank, even if it's 4-5 times as much as they estimated.  Then when you file a fraud complaint and claw back your money, it's suddenly, "wait, wait, wait, did we say $350 shipping?  We really meant $60!  Wait!"  ---fudgesicle--- Buyee.  Hope they enjoyed that box of "as is" PC Engines.  They spent 2 years contacting me afterwards.   

Second, you realize you just spent a -lot- of money on random HuCards.  Then you start looking into exactly what's in the things.  Well, they're a surface mount ROM under a blob of epoxy and covered with black plastic.  The white plastic surrounding it contains nothing.  Even on SF2, there's nothing in that bump.  Fraud!

So, ---fudgesicle--- it.  I'm in this deep on a system with like 3 actually good games.  Might as well keep digging.  There's 2 PCB designs floating around.  One you have printed at 1.6mm and then bulk up the bottom.  The other is two separate 1.2mm boards that you glue together.  There's nothing on the bottom board besides a couple of holes for the EPROM legs.
 
Here's the first one:




Found it here:  https://z-team.itch.io/diy-pc-engine-hucard

Here's the second one:



Found here:   https://www.aussiearcade.com/topic/90002-pc-engine-pcbs-rgb-amp-hucard-controller-board/


Ordered up 10 of each.  Also ordered 10 27C801 & 10 27C040 EPROMs. 

We shall see how this goes...

 

[pbj]

So, PCBWay has given me total hell over that board with no traces on it.  We’ve gone back and forth for over a week and I’ve paid shipping twice.  We shall see.

HuCards are the size of a business card and 2.4mm thick.  My repro cartridges will involve those small PCBs with an EPROM soldered on them.  I’ve also, as previously shown, bought a few loose cards.

I got to thinking about the size challenges, and considered cards holders and all that but then I remembered cassette tapes.

For $12ish I got a box of 30 sealed tapes.  Some selection of beautiful Spanish ballads.

Here’s a quick prototype..







I also finally bought a legitimate PC Engine CD - some of you may dimly remember The Manhole from the late 80s.  It boots, plays, and transititions beautifully which is everything a CDR doesn’t do on this thing.  Good to know.




 

[pbj]

Made a few more… pretty quick and easy.  These are on photo paper but don’t really look any different once in the case.



And since I have all these cassette racks laying around…



It’ll make more sense once I start assembling EPROM cards.

 

[firedance]

Very nice work again 

On the artwork for the cassette cases have you thought about adding some pc engine logos as for me there seems to be a lot of dead black space 

[pbj]

Yeah, I agree it feels a little dead but it also reminds me of KMFDM album covers so I've enjoyed that, too.



This next blurb involves far, far too many hours of research on my part and may be incorrect, but so far I've just got a stack of chips in hand and no PCBs yet.  Might as well document this before I forget.

So there's a design for a USB flashable HuCard out there.  The creator doesn't sell them anymore but he's released all the plans and software for free.  This is important because his software can do the appropriate mirroring and strip region protection.  384Kb roms need the first 256Kb of the image mirrored.  USA roms contain a region check.  JAP roms will run on anything.



That takes care of those obstacles.  The next issue is that D0 - D7 are reversed on PC Engine vs TG-16.  The PCBs I ordered are for PC Engine.  So, until I can actually test this, that means that USA roms are going to have to be rearranged to run this board on PCE, and PCE roms will need flipped for TG16.  Not sure on TG16 roms on this board to a TG16, too bogged down in details to keep it straight.

Anyway, this very helpful app that prepares the rom files refuses to save a version with the outputs flipped.  It will only write to his flashcard (which I guess you could then in turn dump).  I've emailed him and asked if he would consider modifying this, but it's very old software.



Everyone I've asked about how to scramble outputs on roms assures me it's easy but can't point me to a utility or instructions.  So here comes AFS Megadrive Rom-Suite to the rescue.  It's incredible how handy this program has been.




There's also another program intended for NES chips which can be made to work with the 512Kb chips.  I'm not sure how it would do with the 1024Kb eproms as pins 1 is now A19 instead of VPP.  It'll probably work.

[mourix]

Loving the dedication. This should be the point where the rabbit hole makes you get a 3D printer to finish up these hucards

[PL1]

Loving the dedication. This should be the point where the rabbit hole makes you get a 3D printer to finish up these hucards

He'll probably just hit me up for that part.   

Not sure how well it will work since 2mm (overall card thickness) minus the PCB thickness leaves very little wiggle room.
https://consolemods.org/wiki/Dimensions_for_Game_Cartridges


Scott

[pbj]

The first batch of repro pcbs arrives tomorrow.  They’re 1.6mm.  Apparently you’re supposed to bulk them up with something to get them to a good thickness.  I’ve also read that 1.6mm will probably work fine as is.  We will see.  You can buy really cheap plastic cards the size of playing cards.  Glue and trim might do it.

The second batch is a 1.2mm eprom board and then a 1.2mm blank board with a hole for the eprom legs in it.

Going by the rom set I downloaded, there’s less than 30 games over 512Kb.  The 512Kb chips are around $0.50 each.  The 1MB about $1.10 each. 

I’ve also read that PC Engine eprom bootlegs were quite common back in the day.

Anyway, I did pick up some cheap sleeves for my loose HuCards and possibly to mangle for my bootlegs.




 

[pbj]

So my two different boards showed up today.  I only had round hole sockets which I’ve learned are a PITA with 35 year old chips, but I couldn’t resist.

This one is a thin pcb that you solder the chip to and another thin pcb you glue to the bottom. 



And here we go…



Works great, but uses 27C800 chips.  Less than 30 games need a chip that big and they’re three times as expensive as 27C040 which accommodate the rest of the library.

Here’s the other design.  This one has jumpers but it also has sharp edges on the corners for no discernible reason.  He’s got a better revision but hasn’t released the files that I can find.




This one you have to bulk up on the bottom to get the card edge against the connector.  I used four stacked strips of electrical tape for now.



I still haven’t figured out how to modify a US rom to work on these boards… but… soon..

[firedance]

Great work as always 

[pbj]

Well, Klax is known to have region protection that doesn’t work.  Using my chip remapper software to reverse D0 - D7, I got the US rom booting on my PCE Duo.

So, halfway there.

Supposedly changing AD 00 10 29 40 F0 to AD 00 10 29 40 80 in the ROM defeats the region check.  The USB flashable HuCard software makes this change to the rom file, supposedly the Everdrive does it on the fly.

More information here:

https://pcengine.proboards.com/thread/662/american-hucard-region-check-code?page=1   Using my chip remapper software to reverse D0 - D7, I got the US rom booting on my PCE Duo.



Thus far, making this change and then doing the rom reordering hasn’t worked for me.  PC Engines typically require a hardware mod to run TG16 games.  I had hoped to avoid this but I’m in too deep to stop now.


https://gamesx.com/wiki/doku.php?id=imports:pc_engine

[pbj]

Turns out that on a PC Engine Duo, pin 29 isn't connected to anything, so you can just bridge it to pin 30.

So, I did so.  No change in behavior.  At this point, 2 hours into it this morning, I'm halfway convinced there's another layer of physical protection on USA HuCards and until someone burns off the epoxy on a legitimate game we're never going to know for sure.  Swapping the D0-D7 and grounding out pin 29 defeat protection that prevents an actual cartridge from booting but I've yet to encounter anyone else running a US ROM on a PCE PCB.


When you do the mirroring on the 384KB ROMs, they balloon to 640KB.  Makes buying those $1.50 EPROMs a little easier to swallow.

[pbj]

Alright, turns out you don't actually have to do any byte swapping on the ROMs.  I guess it's just a physical lockout thing.  Unsure on the pin 29 thing but that's done.

Derp.

 

[pbj]

Okay, so now that I realized I didn’t need to be messing with the roms, it’s time to make some HuCards!  This is more or less their final form.  Doing some napkin math my cost is about $4 each, so I’ll probably make like… the entire library.










Still a couple of kinks to work out.  As the super glue that is holding the two boards together cured, I wasn’t getting great contact.  A little tape underneath the edge connector instantly fixed that but I think it’s best to let them sit overnight at this point.  I may sandwich something between the boards before I glue them and see how that goes.  Legitimate HuCards are just ever so slightly thicker than these.

I’ve also got some credit card sized blanks coming, those may be the trick.

Anyway, chugging along.

 

[pdco_arcade]

You might consider adhesive transfer tape to stick the pile together.  DigiKey has assorted varieties.
https://www.digikey.com/en/products/filter/tape/908?s=N4IgjCBcpg7LVQGMoDMCGAbAzgUwDQgD2UA2iAMxgAMATNQJwgC6hADgC5QgDKHATgEsAdgHMQAX0IBaWohApIAgK4FiZEAFYWEqSABs8wQBNu0mhHZdIIEIQ4BPNrm7psKXUA
Picking from what is in stock maybe the 9626 ( 2 mil thickness ) or 950 ( 5 mil ) products would be good.  Best I can tell PCB material ( solder mask ) has a "low surface energy" characteristic.  Both models of tape are specified to work with that surface characteristic. 
YMMV - This is all new stuff for me.  I have used adhesive transfer tape before but never give much thought to the surface energy stuff.

[pbj]

The blue HuCard PCBs are so much more visually pleasing but they continue to vex me.  Things shifted further out of alignment overnight and it’s almost impossible to get Neutopia 2 to boot now.  I was resorting to whittling down the unevenness in edges with a sharp knife. Remember blowing on cartridges and wedging them in at funny angles?  It’s exactly like that.

So I spent more time on the square edge pcbs.  They have unnecessary jumpers that have to be populated, but that rectangular shape means alignment is perfect. 

Anyway, today’s haul.

[pdco_arcade]

Here are the HuCARD PCB's with square corners.  Didn't add traces to the 'blank' PCB but did add text in the copper on both sides.  Should be covered by the soldermask.  See the png's.  Think that will work?

[pdco_arcade]

Forgot to ask - think adding small alignment holes ( 2 or 4 ? ) in both PCB would help keep them in alignment while they are being sandwiched?  If so where?  Am thinking some sort of base with vertical posts.  Drop bottom PCB onto the posts, slather with whatever adhesive ( keep away from the posts ) and add the top PCB onto the posts.  Clamp & hold as needed.  I assume the only interface to the game console are the fingers at the end?

[eds1275]

This is really cool. Took me a min to register what the PC Engine was (TG16 where I live.) Radioshack used to have a kiosk with one, they'd put it right outside the door in the mall, and I would rotate it so they couldn't see me playing Bonk for hours on end.

[pbj]

Forgot to ask - think adding small alignment holes ( 2 or 4 ? ) in both PCB would help keep them in alignment while they are being sandwiched?  If so where?  Am thinking some sort of base with vertical posts.  Drop bottom PCB onto the posts, slather with whatever adhesive ( keep away from the posts ) and add the top PCB onto the posts.  Clamp & hold as needed.  I assume the only interface to the game console are the fingers at the end?

Oh man, that's a great idea.  A small hole on the left and right edge would do it.  Or another thought is a spot that would eventually be covered by a label.  Yeah, only the fingerboard interacts with the console.

On your square PCBs, does the top PCB still have rounded edges?  Kinda looks like it does from the png.

[pdco_arcade]

You mean the stuff in the attached image?  ( how to insert image into the message? )
The blue line specifies the PCB physical outline.  Is in file PCB_2_BoardOutline.GKO.  Viewing the file in a gerber view program ( gerbv ) will show the right angle corners.  The red is the copper pour the original author added.  I did not try to fill that in.  Did not seem necessary to me.

About the alignment tool - maybe something easier came to me.  Just take 3 rectangular pieces of something with nice straight sides and thick enough to be higher than the stacked PCB's.  Make borders for the PCB stack by place the 3 pieces of stuff on 3 sides of a PCB to form a sort of cradle and secure those pieces down somehow ( tape ? ).  Then nestle a bottom PCB in the pocket, add adhesive and set the other PCB on top.  Clamp as needed.  The borders should hold it all in-place until the adhesive sets.

The first card listed ( PC ENGINE / HuCARD printed on it ) has 3 offset contacts.  Two are extended closer to the PCB edge while the third is set back a bit from the PCB edge.  Probably they are like this so those closer to the edge make contact first when plugging in a card.  Looks like the extended contact close to side edge of the PCB is +5V while the extended contact in the middle it the pack is GND.  And the function of the contact set back is "L level w/Game Card, H w/o GC".  On both cards appears the contact is tied to GND so I guess means w/Game Card.
 
And comparing overall the 2 card designs the plug contacts on the PC ENGINE / HuCARD model are about 0.01 closer to the PCB edge compared to the plug contacts on the HuCARD model ( rounded corners ) .  Not sure if this matters or not.

Some web sites state the real HuCARD is 2.4mm thick while another states is 3.0mm.  Not sure which is right.

But thinking more about the alignment tool stuff above - poked around the PCBWay site and gathered the following:

For the 1.2mm PCB - need 2 PCB designs fabricated. 
If PCBway will combine the orders into a single shipment charge
  HASL with lead finish, 50 of each PCB ( 100 PCB total ) == $117.92, $2.36 per PCB.
  HASL with lead finish, 25 of each PCB ( 50 PCB total ) == $83.91, $3.36 per PCB.
If PCBWay will not combine the shipping so must pay 2 shipping costs-
  HASL with lead finish, 50 of each PCB ( 100 PCB total ) == $141.84, $2.84 per PCB.
  HASL with lead finish, 25 of each PCB ( 50 PCB total ) == $114.84, $4.59 per PCB.

Using the 2.4mm thick PCB option-
  HASL with lead finish, 50 PCB, $122.93 order total, $2.45 per PCB, no gluing etc., $0.09 difference
  HASL with lead finish, 25 PCB, $100.19 order total, $4.00 per PCB, no gluing etc.

So might consider to just use the 2.4mm option.  To make 50 total PCB the cost difference between the 2X 1.2mm solution and the 1X 2.4mm solution is very little.  And the 2.4mm solution saves from the gluing headaches etc.

In all cases the HASL lead free finish option is less than $10 more if that is a desired option.


About the contact fingers -
Using the HASL might cause connection problems. In the pictures looks like the finish height on the PCB fingers is somewhat irregular.  This could lead to contact problem when inserted. Also the HASL finish not the most durable of the finishes for PCB which will be inserted to connectors.  The hard gold finish is good for that application.

Looks like the most cost effective gold options are the immersion gold or immersion gold + Selective Hard gold.  These cost out the same.  The hard gold on the contact would be the most durable.

To make the 2.4mm PCB with the immersion gold + selective hard gold option -
   IG+SHG finish, 50 PCB, $162.49 order total, $3.25 per PCB, no gluing etc., increase of $0.80 for the good stuff
   IG+SHG finish, 25 PCB, $133.16 order total, $5.33 per PCB, no gluing etc.
   
   So again going for 50, 2.4mm thick PCB seems to be the right option.  Not sure how many are needed. 

[pbj]

Problem with a single layer 2.4mm thick PCB, you're going to have the EPROM pins scraping the console.  With the two board design, you solder to the top PCB, cut the legs off as flush as possible on the bottom, and then glue together.

[pdco_arcade]

A trick used before surface mount became dominant.  Extend the PCB pads, bend the IC leads out 90 degrees, set onto the new pads and solder.  Surface mount style.  No leads protruding through the PCB.

Image is just to show the concept.  Obviously is not ready to actually use.

[pbj]

That’s just crazy enough to work.  I will take calipers to a few HuCards this weekend and report thickness results.

[yamatetsu]

You mean the stuff in the attached image?  ( how to insert image into the message? )

Click on this button



and insert the link to your image between [ img ] and [ /img ].

[pbj]

Didn’t get to the calipers yet, but I did take a closer look at my Neutopia 2 card.  The print is out of alignment on it, just ever so slightly - so the fingers are out of whack.  If I recall correctly, I think they actually sent me 11 of the top boards.  Guess one was a free misprint.

As for gluing, I’ve had good luck with a thin bead of super glue.  Immediately putting the front edge of the cards against a flat surface, and using my hand to align the left and right edges.  Then you sit there and feel like a trained monkey holding it tightly in place for a couple of minutes. 

Anyway, just to further cement how dumb a project this has been, the clone Everdrives have been slightly revised and are down to $16 shipped.  I’ve got three friends with this console and none of them can name any games they want.   

[Malenko]

Anyway, just to further cement how dumb a project this has been, the clone Everdrives have been slightly revised and are down to $16 shipped.  I’ve got three friends with this console and none of them can name any games they want.   

Saramander, Lords of Thunder, Ourun , Galaga 88 or 90 , Ninja Spirit , final lap twin , street fighter 2

I also need one of those controllers =)

EDIT: at $4 a pop I might want the whole library too

[pbj]

Lords of Thunder is a CD.  Burn your own.
Street Fighter 2 is impossible.  Buy your own.

[pbj]

Found calipers, confirmed on a couple of retail HuCards.  2.4mm thick.

[pbj]

pdco_arcade, PCB Way is rejecting the bottom layer PCB - "Failed reason: Lack of the Silkscreen layer."

 

[Malenko]

*pbj tears*

Rabio Lepus Special  -English patch please
Knight Rider Special (ナイトライダースペシャル)  -English patch please
Ninja Spirit
Final lap twin
Saramander
Soldier Blade
Galaga 90
Blazing Llazers

[pbj]

So, I got my blank 0.8mm PVC cards on the mail.  I’m still unsure why I didn’t order these from Amazon.  That takes the French PCBs to the proper 2.4mm thickness.

Used one of these wonky Aussie cards to mark out the channels for the eprom legs.  Plan was to burn the channels with a soldering iron, make a groove.



I actually didn’t burn all the way through.   



Came out pretty good, just ran a pocket knife around the edges to shave off the minor misalignment.  Those ---smurfing--- jumpers continue to be an issue.  I can’t even figure out what 256Kb eprom would be compatible with this system.  Making it impossible to get a good bond in that area.

Simplest solution may be cutting the bottom half inch off the pvc cards and leaving the pins exposed.

Anyway, since alignment is driven by that top PCB, performance is perfect.  I’m giving up on the blue ones.  Plan on soaking them in acetone to dissolve the super glue and pop off those EPROMs.


 

[pdco_arcade]

pdco_arcade, PCB Way is rejecting the bottom layer PCB - "Failed reason: Lack of the Silkscreen layer."

Added top & bottom silk layers.  Was that a complaint with the original order?  PCBWay likes to add the job # into the silk layer to make their job tracking easier.  Also rounded the insertion edge corners 0.025".  The other card has that radius while these originally had 0.100" radius on the corners.  Should make insertion easier.  Might also want to file the leading edges a bit to add some taper there.  That should help reduce insertion effort too.

Also completed the gull wing EPROM mount version.  Too much fun.

Will post both later today after they get a final review.

So, I got my blank 0.8mm PVC cards on the mail.  I’m still unsure why I didn’t order these from Amazon.  That takes the French PCBs to the proper 2.4mm thickness.

Used one of these wonky Aussie cards to mark out the channels for the eprom legs.  Plan was to burn the channels with a soldering iron, make a groove.

Anyway, since alignment is driven by that top PCB, performance is perfect.  I’m giving up on the blue ones.  Plan on soaking them in acetone to dissolve the super glue and pop off those EPROMs.

Don't give up too easy.  Remember you do not like those jumpers on the first model card.

With the gull wing mount - fab @ 1.6mm & attach one of those blank fillers.  Or go for the 2.4mm fab.

The attached files pcb_1_B.png & pcb_2_B.png are more of less the original version with round corners, text in copper and silks for the
'blank pcb.  While pcb_1_wings.png & pcb_2_wings.png show the surface mount idea.

Got fingers crossed all this is correct.

[pbj]

Sir, I await your pcb file revisions like things I haven’t anticipated in at least 20 years.

Meanwhile, playing around with the garbage I have on hand.





PS - Malenko had some beautiful inserts printed intended for 10.4mm jewel cases.  I will begin rotating my loose legitimate HuCards to something more fitting.  I can’t believe I’m buying CD cases in 2023…

[pdco_arcade]

Whew-
Here are the modified PCB - Have slightly rounded corners at insertion end,  have extra pads for surface mount of the EPROM, have 2 new holes for PCB alignment help, modified the insertion fingers & via's to support gold plating if wanted.

Hope it all is correct.  Editing gerber files is a tedious process.  So much easier working with a PCB in the CAD tool. 

Give it all a good review before ordering and go the least expensive route initially. 

[pdco_arcade]

Found on PCBWay site their specification for copper pull back from a non-plated hole is >0.2mm.  I had only about 0.1mm.  So have increased the hole diameter in the bottom copper for the 2 alignment holes.  That is ready as Rev C.

Any other suggestions for changes?  If not I can post Rev C.

[pdco_arcade]

Having heard nothing negative ( or positive ) I am assuming the files are perfect

Attached here are the Rev C versions.  Only change is to open the copper pull back around the 2 new holes for alignment posts to be used when fastening the 2 PCB together.

Again give it all a good review before using them for PCB order.  And go low expense first.

****

How do the cards operate ( this version and the other ) ?  I like the game connector layout in the other version.  Specifically some of the contacts are staggered compared to the majority of others.  Looks like this is how the real HuCard's are fabricated.  I think so the +v and gnd contacts make  first when plugging a card, then the remainder make contact.  But other flash cards use the same layout of of the attached card.  Not sure it matters if the cards are always inserted with the game console power OFF.

About the other style card - is the EPROM size select feature really needed?  I mean will either the 1MiB or 512 KiB EPROM be used or only the 1MiB seen in the pictures?

[pbj]

I ordered 10 of your previous revision boards earlier this week.  They’re in the mail.

I still need to hash out the rom vs jumper situation.  I think it’s like Genesis where the rom doesn’t care so long as the system addresses it correctly.  From the other pcb, it seems like 512Kb roms will work on a 512Kb or 1024Kb chip so long as it’s jumpered to either 4 or 8Mb.  The true test of your board will be the handful of 1024Kb roms.  I haven’t searched too hard but I’m still unsure which 256Kb chips work with this thing.  At 90 cents each for 512Kb chips, I don’t particularly care, either.

I have 9 legitimate HuCards and 1 bootleg Everdrive.  The contact situation seems to vary.  I’m not sure the original PC Engine had the physical lockout to prevent you from inserting or removing cards with the power on.

The boards I had printed from the Aussicade files are such a pain in the ass to use that I’m about to scrap all of them. 

Anyway, stay tuned… I will know more soon…

In other news, I’ve been playing around with artwork for those 3D printed HuCard trays shoved into CD jewel cases.  I’m really happy with the look:



I also beat Splatterhouse this evening.



I also discovered that contemporaneous bootlegs using EPROMs were sold in cassette cases.

 

[pdco_arcade]

So is the z-team design with the EPROM size selection jumpers the preferred design?   Maybe I should have updated that design instead of the aussirarcade design?

[pdco_arcade]

Attached is updated version of the z-team design for review.  This design has the EPROM select size jumpers.  Added the pads to surface mount the EPROM, 2 new holes for pcb alignment during assembly, what else ?.

Had to perform a lot more work on this design re-routing traces to make room for the extra pads.  I think it all is correct however I will give it more review in the next few days.  Look it over well before spending money.
Opinions welcome.

This PCB layout is a bit backwards compared to 'normal' ( to me anyway ) .  The component side is listed as the bottom while the solder side is the top.  Also found a few problems ( I think ) with the original files and fixed them.  An example is in the original PCB files the locations for the EPROM size select jumpers do not have pads in the top copper ( side away from the mounted EPROM ).  In the pictures looks like there is some copper present at those locations.  I guess the PCB fab house added them.  They do not like having plated through holes with no annular rings on the top & bottom copper layers as minimum.

What's next?  Need to investigate that USB flashable HuCard design.  The flash chips are only 1mm thick.  The EPROM chips ( 5mm thick ) look like albatrosses now.

[pbj]

Well, your December 24 revisions arrived and I tested them out.  No need for jumpers, works perfectly with 512 and 1024 chips.

I need to figure out how to bend the eprom legs to try your surface mount thing but got very good results with flush cutters.  I’ve got a piece of wood with two finishing nails for my glueing jig, which also performed very well.

[pdco_arcade]

Good News.  Any thoughts about changes / improvements?  Maybe an adapter to receive the PC Engine card and change to a 32pin DIP pattern to mate with the ERPOM programmer?   So can re-program them without unmounting the EPROM.  Really a problem if using the bent lead idea.

For the lead bending I have used small long nose pliers and work from both ends.  The ones with smooth internal surface on the jaws ( no teeth ).
https://www.harborfreight.com/5-34-in-needle-nose-pliers-63815.html

[lilshawn]

just throwing my 2 cents in...

the 27c801 can be found in a TSOP package (although it is one time programmable on not erasable so you'd have to make sure about your programming) ... but you could probably design a board set like what you have there to flush mount it upside down in a cutout and then slap a sticker over it and it would almost look stock.

[pdco_arcade]

I have been thinking about a similar solution but using the flash chip from that Flash HuCard project.  More readily available and re-programmable.  Not sure if having the chip suspended only by the package leads would be a failure point.  Used normally looks like the chip is slightly off of the PCB surface.  So supported by the package leads anyway.  Having label(s) covering it might reinforce the soldered leads.  Those chips cost $3.50 - $4.20 each though.    PJB has to comment if that is a budget buster or not. 

[lilshawn]

Not sure if having the chip suspended only by the package leads would be a failure point.

if it was a real concern, i would build it, test it, and then fill the void around it with epoxy.

[pdco_arcade]

Is there any reason could not add a contact in either of the the general areas depicted in the image?   Is there anything in the PCEngine / TurboGrafx card slot / connector to made adding a contact a bad thing?

[pbj]

Nope, shouldn't hurt a thing

https://jt-studios.com/product/38pin-pc-engine-connector/

[lilshawn]

Is there any reason could not add a contact in either of the the general areas depicted in the image?   Is there anything in the PCEngine / TurboGrafx card slot / connector to made adding a contact a bad thing?

i mean as long as you aren't using it as a solder pad that will increase thickness, as those 2 spots in particular, are within the "rails" that guide the card in.