Re: Any hints for extracting IIgs processor?

[spec@vax2.concordia.ca (Mitchell Spector)]

In article d a r r e n  j o h n s o n <rocketusa@delphi.com> writes...

>Hi. I just pikked up a Transwarp GS and no instructions.
>I assume the adapter coming from the card goes into the processor slot --

    Yep, you just plug the card into an empty slot (slot 3 is a
good choice) and the CPU ribbon cable into the 65C816 processor
socket, after removing the chip of course.

>except I can't get out the old chip. I know I prolly need a chip-
>extractor tool -- but I'm in the middle of nowhere and don't have
>Radio Shacks, et al, near. Can I get this chip out with some other
>common tool w/o damaging it.

    Common things around the house make better DIP chip extractors
than any official tool you can purchase for the job. I personally
find a small and narrow flat screwdriver head makes a good lever,
or a pair of fine nail scissors can work even better (actually I
used the later to extract DRAMs out of my old Apple IIgs memory
board a few months back, and just last week to pull a dead BIOS
chip from a Pentium board).

    The trick is to wedge something flat between the chip and the
socket (sometimes there is almost no gap, which makes the fine
nail scissors handy for squeezing in the sharp tip of one blade)
and then lever it up slightly. Then do the same on the other end.
You have to do it slowly and carefully, levering each side a bit
more and more until the chip finally pops out of the socket. Just
make sure to discharge static from you body and _not_ to bend or
break any pins (if you do it too quickly or try and lever a chip
all at once you can easily bend or break pins). I'd recommend the
nail scissor blade to lift the chip, then a screwdriver head to
lever it out once you have that large gap between the chip and
socket. Save your old 65C816 incase you need to replace it (stick
the pins in some foam and put it in a safe place).

>What speed does a rev. a 1989 TWGS go, anyhow?

    If it was never upgraded, chances are it is 7 MHz with 8K of
cache. Some really early boards, such as mine, came shipped to
run at 6.25 MHz and need a newer ROM firmware to go any faster.

    To check, examine the tin oscillator in the upper right corner
of the board (it is a little silver colored box with a MHz rating
stamped on it). Look at the megahertz rating and then divide that
number by four to get the speed of your TransWarp GS. For example,
a "25 MHz" oscillator equals 6.25 MHz speed, a "28 MHz" oscillator
equals 7 MHz, a "32 MHz" oscillator equals 8 MHz and so on. As for
the cache setting, if you can see the chips on the daughterboard
(face side up) then you have 8K of cache, if you cannot see them
(just the back of the pins) then you have 32K of cache. You can
always access the TWGS CDA to get information on the card's speed,
cache size and firmware revision of course. It'll automatically
install itself once your card is plugged in and running.

Mitchell Spector
spec@vax2.concordia.ca