Emulation of Jornada 720 with MAME

I recently ran into one of the MAME developers, and he was very interested in adding support for the Jornada 720 to MAME.
Specifically the Jornada 720 since MAME already has Intel SA1110 emulation implemented, and there being a lot of documentation for the Jornada 720.

I sent him all data sheets of the components for now.

He asked me to provide him a ROM dump as well. I don't have one right now, and I don't have a CF card to install _dev_null's Devuan right now either and do one myself.

So if anyone has a ROM dump of a Jornada 720 (and ideally also Jornada 728, in case they are slightly different) lying around, please step forward

I'm excited to see what comes of this!

I didn't think there were any in the public domain?
If you get them, shoot them over to me, we can put them on repository.hpcfactor.com

Ok so I'm working on a tool to just create a ROM dump. It's working already, but I'm not sure if I dump the right stuff

So anyone here who knows more than me, are these assumptions correct:

1. Windows CE has no memory protection, so I can just read and part of the ROM anytime, right?
2. The J720 ROM is 24MByte
3. The ROM is mapped from 0x0000000 to 0x0BFFFFFF

(added bonus picture even though there's not much to see)





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I've found this online:

https://wwwcip.informatik.uni-erlangen.de/~simigern/jornada-7xx/docs...

According to that, System Flash / ROM is 32MB.

Edited by stingraze 2020-12-01 7:37 AM

Exciting news! Ryan Holtz has made some amazing progress on Jornada 720 Emulation, already getting Windows CE to boot up to the point where it's recognizeable!

I reckon it will be a while until emulation will be usable for general purpose, but it's exciting to follow

He posts regular updates about it on his Twitter: https://twitter.com/TheMogMiner

If anyone has high-res photos of both sides of the Jornada 720 mainboard btw, that'd be helpful!





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Congratulations! That's pretty amazing!

If anyone is willing to disassemble theirs and take the photos, here's how.

I'm happy knowing Karpour gets as excited as I do discovering some new feature related to the J720!!!

I don't know how to do a ROM dump...assume it's easy but need clues. I'm running Devuan on my J720 with 64Mb memory card upgrade writing this to you now via the X11/RasPii setup.

May I remind you that a fast SD card with CF adapter actually works better than an actual CF card....for example no root delay is needed in the params config! The adapter sd card to cf card is about $12 and sandisk ultra microsd cards are less expensive and much faster as they are 32 bit vs cf card 16 bit. Really, give it a try...and make partition one at least 10 Gb and Fat 32 to share with win Ce 3.0 as dual boot (place your hp backup file there along with Devuan boot files.

As far as photos go...what sort of resolution do you need. I can easily access the motherboard top by removing the 3 anterior keyboard torx screws...is that adequate or you want the board completely removed. If helpful, I have a dissecting microscope and can take super hi res photos. I may do that anyway and submit them to the/any archive that will have them...we should have such on hand... what say you?

Anyway, love your enthusiasm!! Wanna help too.

Hi!
Awesome news. I attach photos from the mainboard, if he needs detailed photos from a specific section, just tell me.

I think the attaching didn't work maybe?

Specifically it's about the mystery MCU that is connected to the SA1110 that takes care of battery monitoring, touchscreen, backlight and keyboard. On any block diagram I found it's just the "MCU", so it would be good to know what type it is for a start!

Here you go: https://filehorst.de/d/dDzrgEEr

I had already taken some some before I saw Stefan's so here are some more

I am part way through repairing this board so there are some parts missing, but nothing major.

https://ibb.co/DzKrdLy
https://ibb.co/ftfzKXc

Hey Karpour, any update on this? Jornada 720 on MAME would look so awesome!

I've tried the emulation out. It's not particularly usable yet, touch input seems to be extremely finicky and barely wants to work (try clicking a bunch and wiggle the mouse around a bit, or just avoid using the mouse if you possibly can), and you need to run MAME with the debugger on (use the option -debug), but you can get it to boot.

It's very slow on my PC (which has an i5-4670k -- not amazing for emulation, but not a total slouch).
Using the -cheat parameter in MAME to get access to the CPU speed setting slider and underclock the emulation made it run much faster, but touch input stopped working, and it ended up crashing.
I made it to the desktop once, and it took absolutely ages.

Instructions to boot are here in the MAME driver source for the driver:
https://github.com/mamedev/mame/blob/master/src/mame/drivers/jornada...
You absolutely must follow the instructions there with the debugger commands. The driver isn't quite complete enough to boot on its own, and it'll stay stuck on the initial splash screen forever.

Edited by null1024 2021-03-23 12:02 AM

Ooh, emulation of Windows CE on MAME is becoming a thing now? That's awesome! I'd definitely like to try it out.