Digitech XP-100 (old version w/ smd ic & eeprom installed) to XP ALL

[Chrisgk]

Hello,
I am new here but I am into building and messing with audio circuits some years now..I just purchased the old version of a Digitech XP-100 and I am interested in converting it to XP-ALL or XP-ALL+. As I already read in the build guide by digi2t & Govmnt_Lacky and in a thread here, I assume I must follow all the instructions except the internal/external memory selection wiring and the connections to the 3P4T mode selector switch. Any suggestions?
Also from where do you suggest to buy the parts for the conversion? Decibelics for XP-ALL, Deadendfx for the XP-all+, or anyone here who can provide me the right parts for the job? I am based in Greece.
Thanks very much!
Chris

[digi2t]

The difference between the XP-ALL, and XP-ALL+ is patch memory retention (XP-ALLin code, thanks to prehistoricman). The ALL+ version will retain your saved patches within the four different modes. The older ALL version does not. We don't bother with the older ALL version anymore.

As for the internal/external selection, (from memory here...) the XP-100 (only) came in two versions; boot and OS code on the SMD, or on a 27C256 EPROM. For the XP-ALL+, even if your unit has the SMD internal memory, you can ignore it by always booting to the 27C1001. Page 21 of the build doc covers the switching, and R38 function. If you do an XP-ALL+ build, deleting R38 (if present) forces the unit to always boot from the EPROM, and the switching simply tells the unit what code section (mode) on the EPROM to boot from.

The latest build doc is here;
https://drive.google.com/file/d/1aIbRsYi9-_odxECMjSIw4PFZCpxpx_GD/view

[Baran Ismen]

Is there any chance to find a programmed 27c1001? Dead End offers only burning service. This chip is locally available here but I doubt I can find the firmware and find someone to burn it successfully

[siolpa]

Is there any chance to find a programmed 27c1001? Dead End offers only burning service. This chip is locally available here but I doubt I can find the firmware and find someone to burn it successfully

I think not many people are capable of writing it successfully and running it without errors.