thoughts on Digitech Space Station eprom copying?

[caleboaks]

Thanks for the advice! Unfortunately, after making sure that all the connections on the SMD chip were good, I still don't get anything on the display or any output, with or without white noise... Could I have ruined the SMD chip?

My advice would be to upload some good pictures of your mod. Specifically, try to get good shots of the RAM chips, the R30 area, U8, U9 area, your switch and wiring..... anything that could help.

Well here are the pics... I'm well aware of the fact that there's some really ugly soldering in there, but I've tested everything I can think to test with the continuity meter, and it all seems ok. I'm including a link to a video I took of the symptoms. It seems to start working relatively normally after preset #29 or so, but before that it does all sorts of weird crap. I also see that the fourth ram chip isn't seated all the way down, but that socket doesn't want it to go any further, and I get beeps on all pins when I test it.

http://imgur.com/a/a25ri

[Govmnt_Lacky]

@caleboaks

OK... couple things I see from your pics:

1) It looks like you still have R30 installed (the SMD resistor directly below the left-most jack) Unless you do not want stereo output while in XP300 mode.. you need to remove that.

2) Are you trying to have a dual pedal? Do you want to be able to switch between XP100 and XP300 on your mod? If so, could you post up a better pic of your switch wiring?

3) Your RAM chips look suspect. First.. they say NEC JAPAN. The only ones I have ever used and have seen working are NEC IRELAND. Also, they are 150nS access time. Recommended speed for these is no more than 120nS. 100nS or less is best. So, you should use -10 or -80 RAM chips.

4) You also do not have C63 (390nF), Q5 (J113), or Q10 (J113) installed. You HAVE TO have these installed for the XP300 to work properly. Without them, the wet signal is not getting properly mixed with the dry.

[caleboaks]

@caleboaks

OK... couple things I see from your pics:

1) It looks like you still have R30 installed (the SMD resistor directly below the left-most jack) Unless you do not want stereo output while in XP300 mode.. you need to remove that.

2) Are you trying to have a dual pedal? Do you want to be able to switch between XP100 and XP300 on your mod? If so, could you post up a better pic of your switch wiring?

3) Your RAM chips look suspect. First.. they say NEC JAPAN. The only ones I have ever used and have seen working are NEC IRELAND. Also, they are 150nS access time. Recommended speed for these is no more than 120nS. 100nS or less is best. So, you should use -10 or -80 RAM chips.

4) You also do not have C63 (390nF), Q5 (J113), or Q10 (J113) installed. You HAVE TO have these installed for the XP300 to work properly. Without them, the wet signal is not getting properly mixed with the dry.

Dude. You're a golden god of DIY help! I thought I had made sure to buy chips with the right access time, but apparently I didn't, and apparently I didn't look at them for the entire month that I've been troubleshooting this build  I ordered new ram and it immediately stopped making that horrible hissing sound, and started launching me into space every time I hit a string! I ordered the caps and transistors you mentioned too, which I'll install tomorrow when they arrive. But I think it's safe to say that another Space Station/Whammy hybrid has been completed!

Thanks again for your help @Govmnt_Lacky

[Govmnt_Lacky]

Good to hear you are working now...

Once you install C63, Q5, Q10, and remove R30... you will get the XP300 in stereo. Keep in mind that you will lose the Dry Output in XP100 mode though...

[digi2t]

Thanks again for your help @Govmnt_Lacky

The man is God-like. Astounding! 

Glad to hear that we have another success.

[Govmnt_Lacky]

The man is God-like. Astounding! 

I owe it all to Don Dino. He made me an offer I couldn't refuse...

[marmaliser]

And another one lives.  Just realised I don't think i have posted one of my completed builds yet.  Skipped the XP 100 stereo as I just cant get those wires on the SMD pads to be secure enough. 

Also this one uses the new board which is < 5x5cm so it is cheaper to buy at seeed etc and the wiring holes are spaced for connectors if that's your thang.

Have another XP200 on the bench atm and that one is getting the output volume mod as well (and 2 more xp100's to do  )



This made the whole job a lot easier



Once again thanks to Dino and Greg 

[Govmnt_Lacky]

Just a heads up....

If anyone is looking for some EEPROMs (the 27C256) to be burned and shipped to you... hit me up with a PM. I have a ton of them and will not use all of them. Not free but.. we can work out the details. 

[digi2t]

Just a heads up....

If anyone is looking for some EEPROMs (the 27C256) to be burned and shipped to you... hit me up with a PM. I have a ton of them and will not use all of them. Not free but.. we can work out the details. 

Now there's an offer no one can refuse.

Don Dino.

[MüThing]

Any info on doing a dual-boot XP for 100/300 functions WITH stereo out for the 100? I know digi tried to do something like that but I don't know how well that went or whether it'd even be possible to get the stereo back on the 100 mode.

[digi2t]

Any info on doing a dual-boot XP for 100/300 functions WITH stereo out for the 100? I know digi tried to do something like that but I don't know how well that went or whether it'd even be possible to get the stereo back on the 100 mode.

The stereo out in 100 mode has been done and validated. It's covered in the XP-ALL+ section of the build doc, and can be applied in all cases.

[MüThing]

I was thinking more along the lines of stacking eeproms, unless that was what you meant too.

[digi2t]

I was thinking more along the lines of stacking eeproms, unless that was what you meant too.

The relay workaround can be applied to the stacked eprom's version as well. You'll just need to mount the relay somewhere, but the principals of operation are the same. You'll just need an extra layer of switching, like the XP-ALL+.

[slacker]

Hope no one minds me posting this here, it's sort of XPAll related any objections and I'll start my own thread,

Following in from the discussions here http://www.diystompboxes.com/smfforum/index.php?topic=112088.0 I got my logic analyser out and did some poking around the 93C46 eeeprom on the board. Free Electron was spot on it does hold the user settings so by adding multiple chips in a similar way to the main eeproms in the XPAll mod you could have separate user programs for each model. This wouldn't be too difficult, there's handy vias just below the chip that you could solder wires to to take the required signals to a little breakout board with the extra chips on.

If anyone's interested this is how the data is stored on the 93C46.
Addresses 0 - 5 store the User Programs
Address 20 stores the current Factory Program
Address 21 stores the current User Program
Address 22 Stores the current mode, Factory or User

When you change between programs/modes it writes to address 20, 21 or 22 to store the current selection.When you store a program to one of the User Programs it writes to that address to store it.

At power up it reads all those addresses and also from addresses 35 and 37, I'm guessing they hold the pedal calibration values but I haven't tested it.

[digi2t]

Hope no one minds me posting this here, it's sort of XPAll related any objections and I'll start my own thread,

Following in from the discussions here http://www.diystompboxes.com/smfforum/index.php?topic=112088.0 I got my logic analyser out and did some poking around the 93C46 eeeprom on the board. Free Electron was spot on it does hold the user settings so by adding multiple chips in a similar way to the main eeproms in the XPAll mod you could have separate user programs for each model. This wouldn't be too difficult, there's handy vias just below the chip that you could solder wires to to take the required signals to a little breakout board with the extra chips on.

If anyone's interested this is how the data is stored on the 93C46.
Addresses 0 - 5 store the User Programs
Address 20 stores the current Factory Program
Address 21 stores the current User Program
Address 22 Stores the current mode, Factory or User

When you change between programs/modes it writes to address 20, 21 or 22 to store the current selection.When you store a program to one of the User Programs it writes to that address to store it.

At power up it reads all those addresses and also from addresses 35 and 37, I'm guessing they hold the pedal calibration values but I haven't tested it.

You guys are simply brilliant! I'm always slober knockered at how you fellows go about figuring this stuff out.

[Govmnt_Lacky]

Hope no one minds me posting this here, it's sort of XPAll related any objections and I'll start my own thread,

Following in from the discussions here http://www.diystompboxes.com/smfforum/index.php?topic=112088.0 I got my logic analyser out and did some poking around the 93C46 eeeprom on the board. Free Electron was spot on it does hold the user settings so by adding multiple chips in a similar way to the main eeproms in the XPAll mod you could have separate user programs for each model. This wouldn't be too difficult, there's handy vias just below the chip that you could solder wires to to take the required signals to a little breakout board with the extra chips on.

If anyone's interested this is how the data is stored on the 93C46.
Addresses 0 - 5 store the User Programs
Address 20 stores the current Factory Program
Address 21 stores the current User Program
Address 22 Stores the current mode, Factory or User

When you change between programs/modes it writes to address 20, 21 or 22 to store the current selection.When you store a program to one of the User Programs it writes to that address to store it.

At power up it reads all those addresses and also from addresses 35 and 37, I'm guessing they hold the pedal calibration values but I haven't tested it.

I could see this for a multi-EEPROM build but, how could this be accomplished with the single 27C1001 EEPROM builds? A different chip?

[pruttelherrie]

I could see this for a multi-EEPROM build but, how could this be accomplished with the single 27C1001 EEPROM builds? A different chip?

Easy: hang 4 EEPROM chips on the same bus, but with the CS (Chip Select) wired to the rotary so it selects the corresponding chip. Does the rotary have a free wafer?

[Govmnt_Lacky]

I could see this for a multi-EEPROM build but, how could this be accomplished with the single 27C1001 EEPROM builds? A different chip?

Easy: hang 4 EEPROM chips on the same bus, but with the CS (Chip Select) wired to the rotary so it selects the corresponding chip. Does the rotary have a free wafer?

Well, since the A14 line does not need rotary control, I guess it does. On the version that is "in work" it might need more doing. Any ideas slacker? 

[digi2t]

Easy: hang 4 EEPROM chips on the same bus, but with the CS (Chip Select) wired to the rotary so it selects the corresponding chip. Does the rotary have a free wafer?

Sure!

[slacker]

On the version that is "in work" it might need more doing. Any ideas slacker? 

For the PIC based version my eventual aim is to have the PIC emulate the 93C46, so the pedal's processor thinks it's talking to the 93C46 but really it's talking to the PIC, the PIC can store separate settings for each model. This is technically doable, I don't know if I have the programming chops to pull it off though.
In the short term I'll do a version where the PIC selects between multiple 93C46s using something like a CD4051. That would be simple enough to do, the existing PIC has enough spare pins.