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- From: isc10327@nusunix3.nus.sg (ONG TAT-WEE)
- Newsgroups: comp.sys.apple2
- Subject: Re: Accelerator performance
- Message-ID: <1992Sep13.170747.7659@nuscc.nus.sg>
- Date: 13 Sep 92 17:07:47 GMT
- References: <9209122103.AA10783@apple.com>
- Sender: usenet@nuscc.nus.sg
- Organization: National University of Singapore
- Lines: 50
-
- FORDE@UV6.EGLIN.AF.MIL ("ERIC S FORD") writes:
- : > I bought a 8mhz Zip GS around a year ago and only recently
- : >upgraded it to a 9mhz thru a friend. What he did was to change the
- : >crystal and soldered a couple of resistors on board (mine was the
- : >older
- : >design) and added faster cache ram chips. And it works! All it costs
- : >me was only S$50 (US$75) compared to what Zip was charging for an
- : >upgrade (not to mention the freight charges too!). Anyway, both my
- : >friend and I pushed our Zip GS's to 9mhz and both cards have been
- : >functioning perfectly ever since.
- :
- : Can we get more specifics on how you did this?
- :
- First, a correction: S$50 should be around US$30 and not US$75.
- If you have the newer version of the 8mhz zip (v1.02 and above),
- the upgrade is quite simple. Just change the oscillator and cache ram
- chips to faster ones. The oscillator should be 36mhz (divided by 4
- gives 9mhz) and the cache ram chips I used are 20ns ones (available in
- Singapore for S$20 each, abt US$12, 2 chips for 32k, 4 chips for 64k).
- If you are using the older version (v1.01 and below, I got the
- v1.01 Zip), then you'll have to find a friend's 9mhz Zip GS and copy the
- schematics on the new Zip by soldering additional resistors and perhaps
- capacitors as well. After that, change the oscillator and cache rams
- like the above. It worked for mine.
-
- : When I first started reading this newfeed (roughly 1985) articles like this
- : one were common and perhaps the best reason for subscribing. The only
- : things missing here are the specifics on how to make such a mod (including
- : even a crude diagram) and the usual caveat -> this will violate your
- : warranty!
- :
- I know it'll void my warranty but since my Zip is more than 1
- year old, the warranty is gone anyway. Also, considering the $$$ that
- Zip Technologies is charging for an upgrade and the cost of freight from
- Singapore to USA, I took the risk and upgraded it locally; and it paid
- off. My Zip is now running at 9mhz/32k without any problems.
-
- : Teach us, Guru, that we may go on to greater speed!!!
- :
- I think you're mistaken --- I'm not a hardware guru! My friend
- (ex engineering student) is the one who upgraded my (and his) Zip GS!
- But having read up on hardware stuff, I gather that the upgrade can be
- easily performed for anybody with a little technical knowledge and
- steady hands.
-
- : Eric S. Ford
- :
-
- - DOTW -
- There are Apple IIgs users in Singapore too!
-