Z4648252@SFAUSTIN.BITNET (Z4648252) (03/14/89)
Aad and Jos wrote:
"we have mega-problems using the cartridge port on our MEGA ST2 and we think
it is a common problem for all MEGA's with a boardrevision higher than revision
4."
I had a similar problem with my Mega2 when using Spectre 128. After
about an hour of operation, the Spectre would crash. Obviously, the fault
sounded temperature related. Spraying *any* area of the mother board with
Circuit Freeze (my contribution to the ozone hole at the North Pole) would
correct the problem.
Strange...
My dealer ran a diagnostic on my Mega and could find no problems, even
when loading up the cartridge port. Note: the Spectre ran perfectly on other
Mega2's. Sound familiar? Hint: "There are not two STs which are created
equally."
The dealer's engineer, Dean Muller decided to get involved. He does
a lot of ST application hardware prototyping. After several days of
investigation, he discovered that (I'm not an electronic type) two ram
drivers were weak. He piggy-backed two new drivers on top of the old and
the problem stopped. The cost for the drivers was less than $5.00!!!
For my Mega, the drivers are located between the TOS chip area and
the memory chip area.
If anyone wants Dean's phone number and so forth, get in touch with
me. Such a simple fix but it took days to isolate.
It is interesting that he has had to do this fix to four Mega2's
in the past three months, all revision 5's. He says that it is not
the chip selection that is suspect, but the company which made the
chip. Only those revision 5.0 ST's with that brand chip has the
problems with the cartridge port.
Larry Rymal <Z4648252@SFAUSTIN.BITNET>