mrazek@uiucuxc.CSO.UIUC.EDU (02/05/86)
help! I want to upgrade the memory of my AT&T 6300 from 256K to 640K. The first two banks of memory chips are soldered in place so as I understand it, I need to buy a memory expansion board. I had thought that the 6300 was both software and hardware compatible, but after making a few phone calls, I was told that some memory boards work and some don't. I know I can buy the AT&T memory expansion board (list $400 w/256k), but I wish to minimize costs. So I ask: 1) Which memory expansion boards work with the 6300? 2) What makes these boards different from the rest? 3) Is the AT&T memory expansion board any better than the others? I would greatly appreciate any replies. Thanks for your time. Michael Mrazek University of Illinois mrazek@uiucuxa
brad@..UUCP (02/06/86)
I found out today that if you add a third party hard drive to a 6300 (on the 8-bit bus) the cpu slowes down to the speed of an IBM PC while access that memory. The AT&T 6300 I have seen are 2 ways. One you can replace the memory on the mother board which is fine. and the other has 256K on the mother and you can't change that. The one that you can't you have 2 options. 1 buy an AT&T 6300 card that has the 2 connectors on (for the 16-bit bus) and have the 6300 run like a bat out of h**l or, buy a AST 6-Pack or something like that and have the PC run like an IBMPC when running in the the AST memory. I personally would buy the 16-bit card and have the speed rather than save money and have it slower. If you save and have a slower machine why not just buy a slower machine? brad #include <everyone/elses/quotations>
kozowski@reed.UUCP (Eric Kozowski) (02/11/86)
The AT&T expansion board is a 16-bit board as opposed to the IBM 8-bit boards. Also, if only one bank of RAM is soldered on the mother board, you can use 256k RAMs and get a full 640k on the mother board. Eric Kozowski ...!hplabs!tektronix!reed!kozowski
bb@oliveb.UUCP (Bart Berger) (02/13/86)
In article <146000002@uiucuxc> Michael Mrazek writes: > 1) Which memory expansion boards work with the 6300? We've used the AST Megaplus II and Thesys Fastcard I in our Olivetti M24's, which are essentially the same PC as the AT&T 6300, with no problems. The only memory compatibility problem I've heard of is on multi-function boards with a serial or parallel port, which conflicts with the 6300's built in port. Make sure the add-on card can be configured as the second port, not the primary port. > 3) Is the AT&T memory expansion board any better than the others? Well, the AT&T board and the Thesys Fastcard I use the 6300's full 16-bit bus. That means that word accesses on even addresses (like instruction fetches) take one bus cycle, not two. Whether you notice the speed increase probably depends on your application: faster instruction fetches don't help much if your upper memory contains only data. The Thesys card might be a little cheaper (around $325 list price a year ago). I think the AT&T and Thesys cards don't add any additional wait states, but that's probably true of most other expansion cards also. > I would greatly appreciate any replies. Thanks for your time. You're welcome. Bart M. Berger Olivetti A.T.C. Cupertino, CA As usual, the comments above are mine, not Olivetti's.
gmv@cbuxc.UUCP (Mike Vrbanac) (02/13/86)
> I found out today that if you add a third party hard drive to a > 6300 (on the 8-bit bus) the cpu slowes down to the speed of an IBM PC Not exactly. The 8-bit bus converter in the 6300 (I'm not sure about the PLUS) runs at a 4mhz clock rate. The IBM PC is 4.77 mhz. The 6300 cpu still runs at 8mhz. Note that the 6300s with factory equipped hardisks have 8-bit bus controllers so all the hardisks in the 6300 run at that speed. This is why the benchmarks in the press show the 6300 to be slightly slower than the IBM when doing disk i/o intensive stuff. (All the factory 6300 hardisk controllers I've seen are DTC 5150s). > you can replace the memory on the mother board which is fine. and the > other has 256K on the mother and you can't change that. The one that you > can't you have 2 options. 1 buy an AT&T 6300 card that has the 2 connectors > on (for the 16-bit bus) and have the 6300 run like a bat out of h**l or, > buy a AST 6-Pack or something like that and have the PC run like an IBMPC when Close again. The missing element is that a 6300 with all the memory on the motherboard runs with no memory wait states. When it accesses memory on an add-on board in a 16-bit bus slot, it needs a wait state. 8-bit bus memory expansion would be much slower, as the author notes. -- +--------------+------------------------+-----------------+ | Mike Vrbanac | AT&T Bell Laboratories | Columbus, Ahiya | +--------------+------------------+-----------------------+ | Unix: {cbosgd|ihnp4}!cbuxc!gmv | CompuServ: 76054,113 | +---------------------------------+-----------------------+
hrs@homxb.UUCP (H.SILBIGER) (02/14/86)
I have the AT&T memory expansion card with 384k on it, and I have 256k on the motherboard. If I change out the socketed 128k on the motheboard to have all 640k there, is there a way that I could use the expansion card as a 384k ramdisk? Herman Silbiger ihnp4!homxb!hrs
kozowski@reed.UUCP (Eric Kozowski) (02/15/86)
There are 2 third party vendors that make memory cards especially for the 6300 that use the full 16-bit slots. I can't remember who they are, though. Byte had them in their product announcemet area about 5-6months ago. Eric Kozowski #include <disclaimer.h>