MAPPER MEGARAM 512KB not reading SD Card correctly

بواسطة SvaboMSX

Rookie (28)

27-04-2020, 20:59

Even with the working unit the sdmupd mapper.rom command tells, that "oops.. no sd mapper found!!"
I put the cartridge in slot1 of a nms8280. Usually I use my 201P or 501P, but there I do not have floppy disk drive.

Refreshing the CPLD I can not do, as I do not have equipment to do so.

I also put nextor.sys on a ordinary disk and bootet from there - the same behaviour.

Anyway - seems it should not be this time :-) . Thank you so far.
Best regards

بواسطة sd_snatcher

Prophet (3511)

27-04-2020, 22:02

Pentarou wrote:

1) From the photo the Card seems poorly made, examine the soldering of the CPLD pins.

Gosh! Even "Poorly made" sounds like a compliment to the build quality of the cartridge on that picture.

There are many totally misplaced components: C3, C5, R9, and even missing components: the LEDs and their respective resistors.

It's a shame to see such a poor build quality of this nifty open source design.

بواسطة Pentarou

Champion (434)

27-04-2020, 22:55

SvaboMSX wrote:

"oops.. no sd mapper found!!"

I can replicate the problem if I boot the SD mapper in slot2 with another nextor device in slot1...
Very strange, it shouldn't happen But I don't know what could be the issue with your 8280.

Maybe the flashROM used has an unknown manufacturer id?

Any news from the seller?

بواسطة SvaboMSX

Rookie (28)

27-04-2020, 23:18

no - no news from seller. It was a private seller. Sold me an hb-10d. These two cartrigdes have been along with it.

sd_snatcher: Yes.. the LEDs are missing, because there no holes in the cartridge housing. So no need for limiting resistors.
Where do you see a missplaced cap ?

Pentarou: When I have time, I will unsolder the flashROM and try to read it with a programmer. And try this way.
Just ordered a chinese xilinx platform cable and a few XC97144XL ICs. But shipping will take 1-2 month.

enough time to study about CPLD and the design in general :-)

I am happy that at least one works - however it needs the failed one. I want to use those in a MSX1. So I need one for memory mapping extension and the other to read SD cards.