MegaST ROM adapter - black screen

[HigashiJun]

PS: On the provided picture, the socket pins and chip pins seem to be misaligned...

[arti040]

Well, it looks like I bodged something up during soldering the adapter ;-)

[rubber_jonnie]

Well, it looks like I bodged something up during soldering the adapter ;-)

I've reworded your post to remove the swear word, can you please keep it clean.

Thanks

[rubber_jonnie]

PS: On the provided picture, the socket pins and chip pins seem to be misaligned...

I was also thinking that, something that is very easy to do with that particular type of EPROM, I've had that problem with my own of this specific type. The pins bend very easily and don't have a lot of support.

[arti040]

It's just a perspective ;-) All is fitted correctly for sure.

[HigashiJun]

It's just a perspective ;-) All is fitted correctly for sure.

Ok, good to know that the chip is fitted correctly.

[HigashiJun]

Oh, and BTW, may we know which TOS version you're trying to run ?

If you want TOS 2.06, then you also need a TOS decoder to make it work.

[rubber_jonnie]

Oh, and BTW, may we know which TOS version you're trying to run ?

If you want TOS 2.06, then you also need a TOS decoder to make it work.

You must have read my mind, I was just thinking the same :).

@arti040 Since we know the ROM board is the problem, it would help if you could do a couple of things to help us help :)

• Take a picture of the top and bottom of the ROM board making sure they are well lit and in good focus so we can see fine detail.
• Take a close up of the ROM in it's socket just to allow a 2nd opinion view on the alignment and pin 1 location. TBH I compared to one of my own and the pin 1 alignment looks fine, but I really want to see the pin alignment based on my own experiences with that specific ROM type.
• Confirm what TOS versions are on the ROM. As @HigashiJun mentioned, TOS 2.06 requires a decoder board to work with a Mega.

I would still seriously recommend changing the ROM select jumper for a square pin type too for better contact on the jumper itself. If that isn't making contact then you won't see the ROM AFAIK.
It is also worth double checking the soldering under the socket on the bottom of the board with a magnifying glass as it's very easy to get solder bridges or fine whiskers due to the tight pitch of the pins.

[HigashiJun]

You must have read my mind, I was just thinking the same :).

8-)

[Badwolf]

Oh, and BTW, may we know which TOS version you're trying to run ?

If you want TOS 2.06, then you also need a TOS decoder to make it work.

There are four chips.

Two have TOS1.04UK/EmuTOSUK 192k in them. One has EmuTOSPL and Tos1.04UK in it.

These three chips have been tested in my STFM.

The last chip has TOS2.06 and EmuTOS256 in it. I've suggested to Arti changing the chip in case he's randomly picked the TOS2.06 version by accident (none are labelled, I figured it'd be obvious). I've also suggested trying the chips in his STFM, which is known to work. Not heard back.

BW