MEGA ST info - comp.sys.atari.st

Message from discussion MEGA ST info

PHANTOMM_

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More options May 8, 6:30 pm

Newsgroups: comp.sys.atari.st

From: "PHANTOMM_" <phant...@bellsouth.net>

Date: Thu, 8 May 2008 18:30:44 -0400

Local: Thurs, May 8 2008 6:30 pm

Subject: Re: MEGA ST info

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"Ronald J. Hall" <darkl...@suddenlink.net> wrote in message
news:pan.2008.05.08.14.52.07.149073@suddenlink.net...

> On Wed, 07 May 2008 22:33:53 -0400, phantomm_1 wrote:

>> I've ran into a weird problem with a Mega ST. Maybe someone who still
>> reads this group may have seen something similar or knows more about
>> the mega chips.

>> Upon boot up the internal drive will not read any disk (even a blank
>> format).
>> The desktop will come up on screen and I can change resolutions.
>> However if I attach a 2nd Disk Drive, the Mega ST seems to try to format
>> the
>> drive(disk).

>> I can try to access the internal drive from the desktop, when doing so,
>> the drive sounds like there is no disk in the drive to read.

>> I though that the Drive chip may be bad, but I know that other chips in
>> the
>> Mega also have something to do with Drive signals. I think the Sound
>> Chip and maybe the Video Shifter relate drive signals, but not sure
>> what part each control?

>> And does the keyboard have anything to do with the drives?

>> The Mega is a version 5.0xxx motherboard. with TOS 1.4.
>> Stock unit with 4megs. Used very little.

> Hey Barry! I know you've got a lot of other ST stuff lying around - how
> about switching out the floppy drive with a known working one? At least
> that way, you could rule out the drive, before you started chip-chasing.

> The Mega models aren't too hard to take apart.

> Hope this helps.

Already, switched out the internal drive, with a known working mech. And
got the same results.
Also tried an original Atari external disk drive and a GoldenImage which all
work fine on
my 1040STe. I replaced the powersupply and it's purring like a panther. I
mean kitten.

I've had the Mega apart, as I was going to do a few upgrades before this
problem came up.

Reason I ask about the keyboard, is I plugged in a TT keyboard before this
problem came up.
Unless all TT keyboards are the same, the one I used seems to be a non-US
version.
Due to what appears to be a Sign for the UK Pound on one of the number Keys.

I then tried a original Mega keyboard but get the same. I think it's a chip
problem.
Btw the mega acts, you'd think it has its NVRAM messed up. But the mega
doesn't
have NVRAM.

If a bad keyboard can mess up the drives then it's possible that I have 2
bad keyboards, I have another
Mega keyboard that I'm getting ready to try just to make sure. Then going
after the Yamaha chip.
Most of the chips in this mega are socketed, maybe ones loose.

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