Re: Restoring IIGS with Transwarp IIGS --> identification if loose IC

[dalloff@gcfn.org (Dave Althoff Jr)]

Deacon Blue (scavenger@apexmail.com) wrote:
: Hello!

: I'm restoring a IIGS with a TranswarpGS board inside.

: I've little knowledge on the TWGS board myself so I would appreciate some
: help here to get it up & running. The board is marked 'Transwarp GS"
: Copyright 1989 - Applied Engineering REV    TWGS1.5W8S.

: I found a blank, four legged square IC lying loose on the mainboard-base
: which may belong the the TWGS, but I'm not sure on this.

That's a 28 MHz clock crystal.  Even I can recognize that!  8-)

: It has the following print:  "28.000Mhz,  ECS22100,  Japan."

: I've been able to recognise a square connector on the right-side, top corner
: of the TWGS-board.  If the loose chip is meant to sit here,  how should the
: IC be aligned, vertical or horisontal to the onprinted text?

: No matching socket has been identified on the CPU-mainboard.  Any advice
: appreciated!

The socket should be marked U34...yes, in the upper right-hand corner of
the TWGS board.  At least that's what mine says.  If I hold my TWGS so
that the crystal socket is in the upper left-hand corner (that is, with
the chips toward me and the slot connector to the right), the text on the
chip is in normal "reading position".

A more scientific tactic:  There is a dot on the crystal printed directly
above Pin #1.  That pin should be in the upper left-hand corner of the
socket when the board is in a more conventional position (with the slot
connector pointing down).

The card goes in Slot #4, if I remember correctly, and the special 50-pin
connector at the end of the ribbon cable plugs into the CPU slot in place
of the original 65C816.  If your TWGS is like those belonging to most
people on this newsgroup, you can safely lose the 65C816...but if it's
like my TWGS, then you'll want to keep that 65C816 safe so you can drop
back to 3MHz (from 7 MHz with the TWGS you have) when the system goes
unstable.

Which reminds me...anybody got any ideas where I should look for trouble
on my TWGS?  Factory configuration, but once the machine heats up a
little, it starts crashing.  Perhaps I need a new 65C816 for the TWGS?  Or
is there another likely culprit?

--Dave Althoff, ][.
-- 
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