Yes, that’s correct.

[e5frog]

All pins are only supposed to work one way, address in and data out.

But, OK, I understand, I guess that’s why I didn’t find any such suggestion on the other sites…

Best case scenario then is if I can have just a single resistor in series (any ideas about a range, 2k2, 3k3, 10k?).

Otherwise it’s a resistor and a diode to 3V3, 23 address pins, #OE, #CE – so just 25 sets then. 😉

I found the datasheets for both Numonyx and the Intel brands of these 28F128J3. Neither says anything about any ESD protection diodes or anything about ESD at all and neither has any schematics of the input nor outputs.

Question then is if I need to do anything to the data bus as well…

I have written to Numonyx and asked about it, otherwise I guess I’ll have to go the safe way. Most other sources don’t worry about there being 5V on the databus, they just say that the output of a 3V system is usually enough for a 5V system.

• This reply was modified 16 years, 6 months ago by e5frog.

I laid out the flash roms, needed caps, the connector and the dipswitches, put a voltage regulator there but it’s not hooked up yet and tried routing. It seems possible…

This is the pcb adapted for a new connector, haven’t checked it it fits yet though but it’s still in the planning phase so.

Anyway, it seems like it’s possible to make a 32 slot multi-cart with dip-switches.
I need to check to sort out the voltage level converting, check that I have large enough traces for the needed current and correctly hook up the regulator. But even if I need to solder jumpers manually it seems feasible.

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[e5frog]

How about two silicon diodes in series on every address pin?

They have a forward voltage of 1,4V – which gets us in the safe area.

I know people sometimes make 3V out of 5V by connecting three silicon diodes in series…

Something I also have thought of is to connect VSS of the eproms to 1,5V and VCC to 5V. A “zero” from the VB would be at it’s lowest -1,5V which is “OK” since the eproms can handle -2.0V. But it’s normal rate is only -0,5 so it will keep within the absolute maxium ratings but not the normal rating.
Ouputs of the data bus would relative to VB GND be about 5V then… The address bus would get 3,5V from the VB.

• This reply was modified 16 years, 6 months ago by e5frog.

OK, I’m considering 74LVC125 or 126 also… They’re 5V tolerable 3V circuits.

Found another picture with other methods as well.
http://www.siongboon.com/projects/2006-01-08_more_circuit_schematic/

Ahh… a sigh of relief.

5.1. Table 4, Absolute Maximum Ratings
-2.0 < VCC < 5.6 (V) -2.0 < VCCQ < 5.6 (V) Voltage on any input/output signal (except VCC, VCCQ) min: –2.0 max: VCCQ (max) + 2.0 I guess I can run it on 5V then... no I guess that wouldn't be very good, but it can take it if necessary. "I'd use series resistors w/ low voltage drop diodes to shunt to Vcc" How does that look, any picture of a schematic?

The outputs are “High Z” when they’re not outputting data, and it seems like there should be no other unit writing to the databus when the cartridge rom is set to “chip enable” and “ouput enable”.

So I guess the outputs are sorted out then, good, cause the SOIC20 74LS541 took a lot of space.

[e5frog]

If I use a simple buffer circuit CMOS/TTL levels, it will lift the levels to the right level – but should I worry about delay?

I’m thinking this perhaps:
http://www.futurlec.com/74HCT/74HCT541.shtml

Better go for the SMD, even though it LS:
http://www.futurlec.com/74LS/74LS541SMD.shtml

• This reply was modified 16 years, 6 months ago by e5frog.
• This reply was modified 16 years, 6 months ago by e5frog.

The faint “1” on V.F. JP could be the edge of the stamping tool that has left an impression.

Got a new price for 75 units: $11.00 / pcs, but where would I get $825?

I was looking at the ezoflash.com page again and apparently there’s a 128Mbit chip that can also be programmed with the Willem programmer. There has been successful tests with one particular chip that is, it’s likely others work as well.

You have to manually switch the three upper address bits and program 16Mbit at the time (fits fine with the padded VB rom images then). And there has to be a custom adapter made for the TSOP56-capsule. I have found pretty cheap socket(s) and I’m planning to make my own top board for the Sivava adapter set (http://www.sivava.com/buynow.php?pd=T10).

CAD:ing
Currently working on a PCB, I had to make the symbols and description manually, luckily the package was already done.

There is room for 32 16Mbit slots and it will have 16 pins to switch, either I’ll do it by dipswitches – the quick and dirty way – or I’ll setup latches to hold that information and have it run by a menu… The latter would take more time of course, especially if I have to do the programming myself…

HELP LOOK FOR MEMORY?
If you want to help, look for Intel TE28F128J3D, other manufacturer might work as well but the Intel version has been tested and works.

Larger chips will make things easier, and as it seems also cheaper. I saw these for $13.50 and that’s not the cheapest place to buy them – if I can find them elsewhere.

It has been recommended to me to use voltage dividers for the address-inputs in case they’re not TTL-level compatible, and it seems they are not. And level shifters for the data out – it should be possible to get a small packet of 8…

Then a 3v3 regulator and required components for that as well.

So for now it leans more to a single side of components and the usage of a donor cartridge. I guess anyone who wants a multi-cart can send a donor-cartridge and get a discount, and a larger discount for several donor carts…

To make this happen however I will need support to be able to buy all needed parts.

LABEL
It would be fun to stamp the labels (label-contest!!!) with a two digit serialnumber like the original labels have their version number stamped or whatever it is (Mario’s Tennis having 19 for example).
Regarding the label I’m mostly worried about the thin material and glossy finish. Thin enough photo paper might do it – any thoughts on that?

I’ve had lousy result with red-cyan and purple-green, so it would be nice to try a pair of red-blue…

I’m guessing it’s not in Sweden (never heard of Comcast).

😉

VirtualChris wrote:
OK, but what if there’s two exit points, like in my example shown below? (by the way, the game *is* playable in its current form, so tell me what you think of level 2. Too hard? Too easy?)

I tried it, perhaps the cursor could be just a thin line instead of looking the same as the blocks? The mouse moves really slow… Wasn’t there supposed to be a cat as well?

I haven’t figured out the solution yet, you can only place two blocks and then it’s supposed to get to the cheese.

What are the limits of the mouse’s movements, how does it move?

Don’t know if anyone still reads this thread but I got a price from my circuit supplier: $18.50 each…

Which would mean the eprom circuits only for one cartridge would be $148.

Is anyone really interested in a Multi-Cart for around $200?

It should be about 0,4mm then I guess.

I think DogP has a loose one to measure on, so I hope he’ll be able to check.

Just want to figure out if the socket I bought will make a good connection without having to adjust the connectors, do a lot of soldering replacing an original connector and test or disassemble my own unit and measure it when connected.

I got confirmation that the 64Mbit chip is programmable with the hardware I bought without any large fuzz.

So… I guess I need to find someone who sources the reverse tsop version as well.

Normal version is called
Am29LV065DU-90REx
and the reverse is
Am29LV065DU-90RFx

x is the temperature rating, usually “I”.

When I was walking the dog I thought that perhaps a tool could be constructed to bend the pins the other way thereby making reverse tsops myself…

Got it, they didn’t have it in 2×30 so I had to buy 2×40 (probably exists from other sources like farnell.com for example).
Size looks fine, hole spacing fine, I just need to check if I get a good connection with the pins in the VB without modification (other than cutting it down to 2×30).

So, either I remove the original connector from let’s say Mario´s Tennis and solder this one and see if it still works or I disassemble my VB and make a proper investigation.

Sad thing is that it’s probably still cheaper to buy a bunch of ordinary carts than to buy these connectors… On the plus side however is that it would be possible to place components on both sides.

I’ll see what I’ll do, I have a few other things that I need to do before that.

Also it’s only 4mm long so the pcb would have to extend about 1mm outside the shell – and perhaps also be shaped like the original connector to make a proper fit.

RunnerPack, could you get me a pair and I’ll PayPal you some money for them?

Me too, I logged in manually today so I’m guessing it still bugs.

Or grab the “Little Mickey Mouse”-frames from that animation on this page:
http://yahoofreak.com/cartoon-animated-emoticons

I’m going down to the city tomorrow and get one of those 2mm connectors and see if I can make it fit… if it does it will be possible to fit the PCB in the middle and have circuits on both sides.