rost@aqua.dec.com (BRost) (10/09/90)
Hello! I was wondering if anyone would care to comment on the Zubair Z-RAM memory upgrades for the ST. In particular, I have a 520STFM and would like to upgrade to at least 1 meg, but having 2.5M for under $300 is tempting. Also, it appears from the ads that it is a "solderless" instal, is there any difficulty in replacing the clips with hard solder connections? Brian Rost @aqua.dec.com 508-467-6289 **************************************************** * * * The above does not reflect the opinions of * * my employer. * * * * If music is outlawed, only outlaws will be * * musicians. * * * ****************************************************
mwjester@wsuiar.uucp (loki) (10/11/90)
In article <3107@ryn.esg.dec.com>, rost@aqua.dec.com (BRost) writes: > Hello! > > I was wondering if anyone would care to comment on the Zubair Z-RAM memory > upgrades for the ST. In particular, I have a 520STFM and would like to upgrade > to at least 1 meg, but having 2.5M for under $300 is tempting. Also, it > appears from the ads that it is a "solderless" instal, is there any difficulty > in replacing the clips with hard solder connections? I just installed a Z-RAM upgrade in my 1040ST. Installation was extremely easy - pull the video shifter chip, plug in the ZRAM board, plug the chip into the ZRAM, and plug the connector at the end of the ribbon cable into the Atari MMU. I bought the unpopulated board from E. Arthur Brown for $115, and the chips from Microprocessors Unlimited for $208 (32 of them). One of the nice things about the ZRAM upgrade is that the same board will work with any ST, as the MMU connection is on a cable. The Tech Specialists upgrade (one of which I have installed in a 520ST) has the MMU connector on the main board, and the shifter connection on a cable, so it is highly dependent on motherboard layout. Downside: the RF shield (that big piece of sheet metal) will not fit over the ZRAM board, so you either have to do without or cut out a piece with tinsnips. No big deal, but you are no longer class B, and you can't run the ST at home legally (FCC class B deals with residential environments). Overall, I *love* it. BTW, the design does *not* lend itself to soldering - this is pretty much true of anything connecting to the MMU, I think. Hope this helps! Max J.
kentd@FtCollins.NCR.com (Kent.Dalton) (10/12/90)
> One of the nice things about the ZRAM upgrade is that the same board will > work with any ST, as the MMU connection is on a cable. This is not exactly true. I have two 520's, one an old STm and the other an STfm. In the STm the ZRAM cable is significantly too short to reach the MMU from the shifter and even if it were the IKBD processor is right over the shifter box and the extra height of the ZRAM board keeps the keyboard and case from being put back together properly. Fortunately the board fits in the STfm properly, and since thats what the original poster inquired about he shouldn't have problems either. Quiz: Which comes in more flavors ST motherboards or Baskin-Robbins Ice Cream? :^) Three other tips for all STer's wanting to do RAM upgrades: 1. Open the ST up _before_ you buy... My STfm, much to my chagrin, had the video shifter soldered in rather than socketed. (That's why I tried it on my old 520 first.) This meant I had to go to the extra trouble of desoldering the shifter and putting in a new socket. 2. Another reason to open up the ST first is that some 520/1040's were shipped with an MMU that can only address 1Mb max. I don't have the part number memorized but if anyone is interested I can post the part number of the "Good" MMU. 3. Zubair highly recommends Samsung DRAMs for use with their product. They strongly discourage use of Oki, Hyundai, and Micron brand chips because they tend to load down the power supply excessively resulting in erratic operation. -- /**************************************************************************/ /* Kent Dalton * EMail: Kent.Dalton@FtCollins.NCR.COM */ /* NCR Microelectronics * CIS: 72320,3306 */ /* Fort Collins, Colorado * "This mind intentionally left blank" */ /* (303)223-5100 X-319 * All standard disclaimers apply */ /**************************************************************************/
kentd@FtCollins.NCR.com (Kent.Dalton) (10/14/90)
The "good" MMU which can address 4Mb is Part #: C025912-38 For those that are unfortunate enough to not have this MMU, B&C Computer Visions will sell you one for $28. Their phone is 1-408-749-1003. -- /**************************************************************************/ /* Kent Dalton * EMail: Kent.Dalton@FtCollins.NCR.COM */ /* NCR Microelectronics * CIS: 72320,3306 */ /* Fort Collins, Colorado * "This mind intentionally left blank" */ /* (303)223-5100 X-319 * All standard disclaimers apply */ /**************************************************************************/
focke@gmdzi.gmd.de (Stefan Focke) (10/17/90)
kentd@FtCollins.NCR.com (Kent.Dalton) writes: > 2. Another reason to open up the ST first is that some 520/1040's were >shipped with an MMU that can only address 1Mb max. I don't have the part >number memorized but if anyone is interested I can post the part number >of the "Good" MMU. > Please tell us the part number of good MMUs. Thanks Stefan ------------------------------------------------------------------- Stefan Focke Tel. 02241-14-2265 GMD-Z2.W e-mail: focke@gmdzi.uucp Postfach 1240 focke@gmdzi.gmd.de 5205 St. Augustin 1 ...!{uunet!mcvax!}unido!gmdzi!focke