earl@trsvax.UUCP (07/08/89)
/* ---------- "8MB Memory Expansion for 4000LX" ---------- */
I want to add 8MB of SIMM memory to a 4000LX which currently has
2MB on the motherboard and a 0-K memory expansion board with 8 empty
slots.
I have two questions:
1) The 2MB on the motherboard is made up of 8 256kB chips. Can
I mix the 256kB and 1MB chips and just put the 8 1-MB chip on
to the expansion board (to get a total of 10 Meg)? Or must I
junk the 256kB chips and replace them with the 1-MB chips (to
get a total of 8 Meg)?
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
It isn't quite so simple. First you can't mix chips on a board. They
are either all 256k or 1 meg chips.
Mother board. You can put in 2 meg's worth of 256k chips, or you can
put in 8 meg's worth of 1 meg chips. You could run only with 4 banks
of chips installed (1 meg/4 meg), but this turns off interleaving which
makes the machine run slower for memory accesses.
Extra 0-k memory expansion board. You can put in 4 banks of chips for
1 meg or 4 meg of Ram, or you can fill it up properly for 2meg/8meg
of Ram.
Basically, without mixing the chips you can do 1meg, 2meg, 4meg, 8 meg,
or 16 meg. memory configurations.
******************************************
2) Radio Shack is selling the 8MB 80ns expansion memory (Part # 2551-33)
at an outrageous price of $6000! Other chip vendors are advertising
prices of under $1500. Is Radio Shack really so out of touch with
reality or are these other vendors on the level?
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I've heard alot of bad stories about vendors only existing for a little
while, they seem to go out of business after they've gotten your money.
You need to be careful here.
Many vendors advertise really low prices as, sort of, a come on. They
always seem to be sold out when you try and buy some chips. But they
can always quote a similar chip(s) at higher prices, of which they have
jillions in stock. The vendors with really good prices always seem to
want the order "prepaid" before they'll ship.
I know of one vendor who was selling defective SIMM board packages at
great prices. The boards had good chips, but the pc board was really
crummy, thus you had a lot of trouble trying to get the boards installed
and working properly. Another vendor was selling chips that failed one
or more manufacturer tests (manufacturer fallouts) for juicy prices. I
don't know if it would be worth the chance. Maybe the chips are still
useable, I don't know. Considering the complexity of 1 meg chips, it
would be attractive to sell off "defective" stocks and still get some
money for them.
Considering what all the big companies charge for their memory boards
or chips, Tandy's are actually quite well priced. When you shop around
looking for really low prices you may or may not be getting such a good
deal after all. It depends. You may be getting exactly what you paid for
****************************
- Paul
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Paul H. Wong | Digital Equipment Corporation
110 Spit Brook Road | EASYnet: DIMSUM::PWONG
ZKO2-2/M28 | ARPAnet: pwong@dimsum.dec.com
Nashua, NH 03062-2698 | Usenet : ...!decwrl!dimsum.dec.com!pwong
U.S.A. | Phone : (603) 881-2575
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<This information is provided by an individual and is not nor should be
construed as being provided by Radio Shack or Tandy Corp. Radio
Shack/Tandy Corp has no obligation to support the information provided
in any way. >
Earl W. Bollinger
@ <trsvax!earl>
"You were in the Clone Wars!", said Luke excitedly.
"Yes", replied Obi Wan, "I was a DOS programmer. But that was before the dark
times, before OS2."