One chip MSX recovery

By ivanovic

Resident (33)

ivanovic's picture

23-12-2014, 11:23

Hi guys!
I've a one chip msx which is running fine in terms of rom and dsk load (graphics, sound, cpu...) but has no working keyboard and no working slots meaning I can not use a keyboard once in basic or msxdos and can also not run original cartridges

I manage to run some games first via autoexec.bat file now using sofarun but I'd like to recover it if possible

I've reflashed to original old and tested, then flashed to latest kdl version 3.3 with no luck
In the last MSX meeting in Barcelona some colleagues suggested using a cable to restore the machine and I managed to contact a user who own one and can support me.

The problem is he recovered a Zemix and is also not very familiar with the steps needed to recover a one chip msx

Therefore I'd like anyone with knowledge on that subject to help me by explaining here what are the steps, files needed and risks

thanks for your support!

I found this info from KDL, step 4 is not clear for me.
Run the programmer means the altera programmer
Active serial programming is a functionality of the program?
Is this updated or do I need to worry about alter programmer new versions?
Is recovery.pof file in any KDL distribution valid? Which will be the final state once done?(which reference table do I need to check in regards to DIP switch?)

Recovery Guide
Here is how to flash the device after a failed update using a personal computer with Windows OS.

1. Buy and install a compatible download cable for EPCS4 like USB ByteBlaster.

2. Download and install Altera Programmer for Windows (freeware):

3. Open the case of your 1chipMSX or Zemmix Neo and attach the cable on the JTAG connector with the pin-1 towards the front of device.

4. Run the programmer and power on the device, select active serial programming method to load the 'recovery.pof' file.

Happy OCM!
KdL 2013.12.15

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By Grauw

Ascended (10821)

Grauw's picture

23-12-2014, 13:38

If you can reflash the firmware, I don’t know what good the recovery procedure will be. As far as I know it’s just an alternative way to install the firmware in case the device gets bricked.

Are you sure the problem is not the keyboard? I assume you use an USB keyboard with one of those little adapter plugs to PS/2. However, does the keyboard support PS/2? Most don’t, nowadays, and if the keyboard doesn’t support PS/2 then the adapter plug will do nothing. You need to be sure to use a keyboard that explicitly says on the box that it supports PS/2. Oh, and the USB ports on the front do nothing, so don’t try and connect a keyboard to those. You need to use the PS/2 port on the back.

As for the slots not working, what is the position of the DIP switches? It is possible to set both slots so that they act as internal MegaRAM and ignore the external slots, then no cartridges will work. Hearing that rom loading works, at least one of the dip switches must be on. See the “dip-sw user manual v3.2.pdf” in the KdL OCM-PLD Pack v3.2 for reference. For the original firmware the positions may be different, consult the manual.

By ivanovic

Resident (33)

ivanovic's picture

05-01-2015, 12:21

Thanks Grauw

USB keyboard is connected via PS/2 adapter and is PS/2 compatible... the fact is it used to work and does not now. Also tried other keyboards but seem I'm "frying" any keyboard I try meaning it does not work anymore attached to any computer Smile

DIP switch is OK as far as I see in the OCM-PLD user manual (both original and newest version) I tested several times
Funny enough the new Goonies Cartridge published recently by a Spanish developer work fine but rest of cartridges don't Smile

Is there any special reset (soft and hard reset) procedure in one chip msx?

I've met a colleague at the latest MSX meeting in Barcelona and we will try the restore using his byteblaster soon
I'll keep you posted

By Grauw

Ascended (10821)

Grauw's picture

05-01-2015, 18:51

It’s starting to sound more and more like a hardware issue to me… Bent pins, stray metal flake, something like that?