Eprom Burner

[Memblers]

29F flash is programmable with 5V, 28F types needs higher voltage.

[sevast]

At least the willem programmer I have will step up the usb 5 volts to the necessary 12.5 volts. Depending on your programmer, there is a good chance that is not the issue.

[NESvirus_981]

I made a programmer that was very cheap probably under $10 depending on what you have lying around.
http://www.zws.com/products/epromr2/epromr_stage1.html
Futurlec is great for parts and EPROM's. I think it would take months for the sun to erase an EPROM, not too much UVC around luckily.

Hi! I'm trying to build this ZWS emprom Reader/Burner, but I have some doubts. Maybe you can help me:

1 - In the original project (www.zws.com), pin32 of the EPROM socket goes connected to nothing. Do you connect it to Vcc?

2 - does the trimpot regulates LM317 voltage only?

This is the only doubts about the circuit, since I made a board schematic and the device is already constructed.

Thanx!

[Lloyd Gordon]

Pin 32 definitely connects to the regulated 5V+ from the 7805. The trimpot does just regulate the LM317. I added bypass capacitors for all the IC's which are recommended. I also modified it slightly adding an extra dipswitch so it will program the 27C080 1 mbyte EPROM's. I hope you are using a ZIF EPROM socket, they are really cheap from Futurlec. Let me know if you have problems. By the way, I run mine by booting right to Win98 DOS and use a really old Pentium 90 with a bidirectional parallel port.

[NESvirus_981]

Pin 32 definitely connects to the regulated 5V+ from the 7805. The trimpot does just regulate the LM317. I added bypass capacitors for all the IC's which are recommended. I also modified it slightly adding an extra dipswitch so it will program the 27C080 1 mbyte EPROM's. I hope you are using a ZIF EPROM socket, they are really cheap from Futurlec. Let me know if you have problems. By the way, I run mine by booting right to Win98 DOS and use a really old Pentium 90 with a bidirectional parallel port.

Hi, Lloyd Gordon! Thank you very much for your support. I've tried to contact zws and Mike Gordon (from the 27C801 mod) without success.

1 - Just like I was thinking: the trimpot regulates only the LM317. But... I used a 12Vcc plugpack and my voltage measures stands for:

a ) 5Vcc in each 4040 (normal)

b ) no voltage at EPROM socket (because in the original ZWS project there's no connection for pin32, different from Mike Gordon Project).

c ) - The trimpot isn't changing the LM317 voltage, although the voltage at DB25 pin16 (init) is normal, I think (~5Vcc). Does voltage change occurs only with the EPROM burner connected to the parallel port? I'm using a vertical trimpot, and my connections are:



Is this right?

2 - I didn't use the 240ohms resistor, since I'm unable to find this measure So, I'm using a 270ohms instead. I think there's no problem...

3 - So, what do you think about the LM317 voltage? Does my trimpot is wired correctly?

4 - And.... if you connect the pin 32 to 5Vcc, How can the programmer burn/read 27C256, witch has 28 pins?

My initial tests where done without connect to the parallel port, because I must make the cable first. Btw, I've included all the capacitors mentioned by Mike Gordon mod.


Sorry for bother you, but I'm very confident cool about this project.

Cheers

[Lloyd Gordon]

1) You must connect the 5V+ to pin 32 of the EPROM socket. Otherwise you will not be able to use any 32 pin EPROM
2)You seem to have connected the trimpot as a fixed resistor. That is likely why the voltage is not changing. The connection to the wiper arm must be used. One of the other connectors must be used as the other connection to the trimpot. You really should use a multiturn trimpot for the variable resistor as it will be very hard to set the Vpp otherwise. The multiturn ones are only a few cents more.
3)Using a 270 Ohm resistor will change the voltage range. Likely you will still be able to set the proper Vpp. Try it out and if you can't, use a 240 Ohm, they are readily available. I'll even mail you one if you want.
4)When you use the Eprom software it tells you how to set the dipswitches. For the 28 pin ones pin 28 gets 5V+. For the 32 pin ones, A17 goes to pin 30. You must always put the EPROM at the "lower" end of the socket so the pins are aligned properly.
5)I get the feeling that this is sort of new to you. I'm not being critical. I've made tons of crazy mistakes such as vaporizing tools and frying components. However, I advise you to check each connection at least 3 times before trying it out. I make a separate copy of the schematic and check off every connection as I use a multimeter to check the actual connection. I also check all adjacent pins and connectors to make sure they don't connect where they shouldn't. Even then I still pick up some errors. Keep trying, it's lots of fun getting stuff to work.
6)Don't make a parallel port cable. It's wasted work. I just soldered a 25 pin connector to the EPROM'er board and it sticks directly into the computer parallel port with no cable at all. It's very convenient, cheap and easy and avoids problems with long cables.

[NESvirus_981]

Hi, Lloyd Gordon! Your tips are awesome! I've waited years (seriously) for someone to help me in this project!!

1 - I take all your tips as a bless. You're right, I'm not too good with electronics, altough I have some knowledge and a digital multimeter. I keep checking all the connection and fixed various of them. Also, I made some extra holes in the board, in order to make changes in a more simple way. However, I'm reading EPROM/NES stuff for years, and only now I'm feeling able to do this project.

2 - Just like I've suspected: the ZWS project has an error about the pin32 of the socket. I was wondering: how can the eprom has power suply without this connection? I've included some extra holes for this purpose, and it's only a matter of wire a jumper.

3 - Yes, just like I've figured. My trimpot connection is wired like a common 10K resistor. So, I must wire pin 1 to somewhere. Ground? And can I free pin 2 or 3 instead?

Is the "wiper" arm the pin 1 of the trimpot in the picture, right? And I don't know about "multiturn trimpot" (sorry, but english is not my natural language) Can you point me to some pictures of this component?

4 - Can you believe I was unable to find a 240ohms resistor in here? The only measures I could find was 220 and 270ohms. Very strange. Thank you for your offer, but I really don't want to bother you. I'll try with the 270ohms resistor and if things burn out, I'll use the 240 instead.

5 - I've choice the parallel cable for some reasons. The mais reason is because I was unable do make correct holes in order to wire the DB25 connector 90º directly. So I decided to make this cable (less than 1 meter, like recommended). Also, it's interesting for me to operate the unit while sited down to my computer chair. Finally, there's a serious space problem in my room....

6 - I'll remember the correct position of the 28pin EPROMs. Good advice!

7 - My plugpack suplies a maximum voltage of 12Vcc. Do you think it's enough or should I buy a 18Vcc like recommended?

Thanks!

[Lloyd Gordon]

The lack of a 5V+ connection was not actually a mistake on the schematic. Lots of things are left off schematics as they are "understood". This is one of them. Another is the use of 0.1 uf bypass capacitors from ground to the 5V+ on each IC. These should be as close as possible to the IC's to bypass voltage transients and are good practice. The variable resistor in this circuit needs only two leads connected but one must be the one connecting to the wiper arm. One of the other two leads is left open. Multiturn variable resistors look like little rectangular or square boxes with 3 leads and a screw head. They take multiple 360 degree turns to go through the full resistance range and are much easier and more stable to use. If the wall-wart power is not high enough then the Vpp might drop below the critical level on a EPROM write operation. This would be very buggy. Best to go higher than the 12V+ but it might be Ok.

[NESvirus_981]

Very good! I'll try this fixes next weekend.

[calvinthedestroyer]

I have been wanting to get a BK programer.
http://www.bkprecision.com/

I want to use it for my test cart:
http://www.akroncdnr.com/ph/users/a4s8b ... oard01.JPG

I also want it for other PIC's and progects, Do you guys have any sugestions? What model / brand do you prefer?
I've used a BK precision 45 before and it was nice, To bad it cost over $400.

I don't have access to it anymore. It belong to my boss and I don't work there anymore.

Thanks
calvinthedestroyer www.dsprototyping.com

[dXtr]

the willem programmers can do e(e)prom, flash and pic (from what I understand) and cost like 35$ on ebay

[Memblers]

It depends on what your other projects might be. Here's what I use:
EPROM emulator for quick testing during development.
Willem programmer for burning and testing memory chips (Flash, OTPs, and SRAM).
Cheap ICD2 clone for PIC work. Mostly because the Willem didn't support the newer PIC I'm using.

That's about $300 worth of stuff. Not counting adapters and misc stuff. The only chips I can't use that I'd like to are PLDs. There are some "TOP" brand universal programmers that sell for under $100, I don't know how well they compare to Willems but I know they do support PLDs in some way and lower voltage chips too.

[kyuusaku]

TOP brand (and most other cheap Chinese programmers) have very limited programming support for PLDs; generally you're stuck with Lattice GALs and compatibles. It's really necessary to track down archaic programmers for their PLD programming algorithms if you're interested in programming PAL, more common GALs, PALCE or PEEL (and of course other types of SPLD and EPLD.)

[Coleman]

OK it looks like i am the window licker here so if you could all pardon my newbness i have a few questions that seem to be taken for granted in this thread.
Basicly i came across a sight that offers Japanese famicom games translated into english and playable on nes format and i am trying to figure out what i will need to be able to do in order to do that on my own - the site is charging way more money than i want to pay per game? Could someone please help me out here?

[nineTENdo]

long time no post!!!!

well anyways ive been out of messageboard loop for sometime now and im ready to actully start testing my code ive been working out on my own.
i want to buy this http://cgi.ebay.com/Standard-Dual-Power ... dZViewItem

Should i, any suggestions?

Will i be able to write to a 6502 chip with this?

ill ask again later after i run some tests on it and search the sites for more info. but write now i just want to able to display a simple name table.

its good to be back and thanks again
el