salmassr@oiscola.Columbia.NCR.COM (Samer Almassri) (11/07/89)
I am interested in putting a 286 clone together, but I can't seem to decide
which motherboard to use. There are a lot of makes out there, at widely
varying prices. While a low price is desirable, reliability and good
performance are of paramount concern.
Any recommendations (along with names of reliable dealers) are most
welcome.
Also what is what is the difference between static and dynamic RAM?
Which one is usually used any why?
Thanks in Advance...
/////////////////////////////////////////
// Samer Almassri //
// NCR Office Information Systems //
// 3245 Platt Springs Road //
// W. Columbia, SC 290169 //
// (803) 739-7858 //
// salmassr@oiscola.Columbia.NCR.COM //
/////////////////////////////////////////cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn) (11/08/89)
In article <112@oiscola.Columbia.NCR.COM> salmassr@oiscola.Columbia.NCR.COM (Samer Almassri) writes:
$Any recommendations (along with names of reliable dealers) are most
$welcome.
My AT clone uses a Suntac motherboard (including the Suntac chipset).
I haven't had any problems with it. It allows for up to 4M on the motherboard
(512K/640K/1M/2M/4M; you can use the memory above 640K either as extended or
as expanded memory); it's a baby-size board with eight expansion slots (I don't
recall how many are 16-bit and how many are 8-bit); it runs at 8/12 MHz, though
they may have upgraded this since then.
$Also what is what is the difference between static and dynamic RAM?
$Which one is usually used any why?
Several differences. Static RAM will maintain its contents as long as
you keep the power turned on. Dynamic RAM has to be read periodically (and
we're talking several times a second here) or it forgets its contents; this
is accomplished automatically by circuitry somewhere on your motherboard
and is known as "refresh". This is due to the design of the cells used to
store each bit. Static RAM uses a much more complicated cell which is
essentially a flip-flop; dynamic RAM uses a much simpler cell. Therefore,
you get more dynamic RAM on one chip than you can with static, and this is
why Dynamic is used. Lower costs and less packages for a given amount of
memory.
Also, dynamic RAMs typically have multiplexed addresses, where you have
to feed it the address in two chunks, whereas static RAMs usually have just
one. This makes dynamic RAM a fair bit slower than static. Therefore,
in machines with caches, typically the main memory is dynamic and runs
with at least one wait state, while the cache memory is static and runs
without wait states.
There have been clones with all static memory (I remember seeing one
advertised that was a 386 clone, probably 16 MHz, that advertised 1M of
static, no-wait-state memory); however, these are pretty rare (Howie, don't
tell me you have one of these, too :-)
--
Stephen M. Dunn cs4g6ag@maccs.dcss.mcmaster.ca
<std_disclaimer.h> = "\nI'm only an undergraduate!!!\n";
****************************************************************************
They say the best in life is free // but if you don't pay then you don't eatfordke@ingr.com (Keith Ford x8614) (11/08/89)
In article <112@oiscola.Columbia.NCR.COM> salmassr@oiscola.Columbia.NCR.COM (Samer Almassri) writes: >I am interested in putting a 286 clone together, but I can't seem to decide >which motherboard to use. There are a lot of makes out there, at widely I have recently purchased 286-12MHz and 286-16MHz kits from Jameco Electronics. They are in a kit form, no soldering iron required. They have worked flawlessly! :) They use AMI (or was it Award?) BIOS and the 16MHz has the NEAT chipset. >Also what is what is the difference between static and dynamic RAM? Most simply from an application point of view, the static RAM can maintain it's data when connected to a low current source such as a battery. This allows data stored there to remain, even after the machine is turned off. Jameco @ 415-592-8121 (I am not in any way associated with Jameco, just a happy customer.) -- _________________________________________________________________________ \____________________ uunet!ingr!b23b!dragon!keith _____________________/ "Fer cryin' out loud, research physicists need porsches too!" -Opus "...the Trees are all kept equal by hatchet, axe, and saw." -Rush
dale@oakhill.UUCP (Dale Stevens) (11/09/89)
In article <7321@ingr.com> fordke@ingr.UUCP (Keith Ford x8614) writes: >I have recently purchased 286-12MHz and 286-16MHz kits from Jameco >Electronics. They are in a kit form, no soldering iron required. >They have worked flawlessly! :) They use AMI (or was it Award?) >BIOS and the 16MHz has the NEAT chipset. How much $ for one of these? > "Fer cryin' out loud, research physicists need porsches too!" -Opus -- ---- Dale Stevens. Motorola Inc. cs.utexas.edu!oakhill!apache!dale
plim@hpsgpa.HP.COM (Peter Lim) (11/09/89)
> > I am interested in putting a 286 clone together, but I can't seem to decide > which motherboard to use. There are a lot of makes out there, at widely > varying prices. While a low price is desirable, reliability and good > performance are of paramount concern. > Seriously, why bother with 286 ? When low end 386 (or 386SX) costs about the same ! Just look at Byte or other PC magazine and you will see plenty of them advertised. Since I am not in the States I am not in the position to recommend any dealers (I deal with those in Singapore). > Also what is what is the difference between static and dynamic RAM? > Which one is usually used any why? > Static RAM is fast and expensive and in PC context only used for cache memory of high end cached 386 machines. Dynamic RAM is the memory used in most PC's. Why ? It's CHEAP ! (may be except for the period from 1987 to 1988) In general, as a rule of the thumb, you will need DRAM of 100 ns or faster if you use a 20 MHz 386, 80 ns or faster for 25 MHz. For 286, I think it's 100 ns for 12 MHz and 80 ns for 16 MHz (I mean zero wait state). Hope these are useful. Regards, Peter Lim. HP Singapore IC Design Center. E-mail address: plim@hpsgwg Snail Mail address: Peter Lim Hewlett Packard Singapore, (ICDS, ICS) 1150, Depot Road, Singapore 0410. Telephone: (065)-279-2289
rcd@ico.isc.com (Dick Dunn) (11/10/89)
In a note about some other stuff, fordke@ingr.com (Keith Ford x8614) writes: > >Also what is what is the difference between static and dynamic RAM? > > Most simply from an application point of view, the static RAM can maintain > it's data when connected to a low current source such as a battery. This > allows data stored there to remain, even after the machine is turned off. Not entirely wrong, but off-base. Information which needs to be maintained with the power off is often stored in CMOS RAM, which is static RAM. CMOS is a semiconductor technology notable for very low power consumption, hence a battery can maintain it. However, what the "static" really means is that if you keep power on the memory, it will "remember". There are SRAMs which are not at all low-power. The "static" contrasts with "dynamic"--DRAMs are what are used in almost all regular main memory systems--e.g., the memory on your PC. DRAMs may actually require less power than SRAMs. The "dynamic" refers to the fact that the information has to be refreshed periodically. In effect a DRAM remembers by storing charge, but the charge tends to leak out. So you refresh the memory by reading what's there (before it all leaks out) and rewriting it. If you're a software type, you don't have to worry about any of this...it's all behind the scenes; there's hardware to do the refresh. (The interval between refreshes is short--on an AT, each piece of memory is refreshed about every 4 milliseconds.) -- Dick Dunn rcd@ico.isc.com uucp: {ncar,nbires}!ico!rcd (303)449-2870 ...Keep your day job 'til your night job pays.
u2zj@vax5.CIT.CORNELL.EDU (11/15/89)
In article <2589@sioux.oakhill.UUCP> dale@sioux.UUCP (Dale Stevens) writes: >In article <7321@ingr.com> fordke@ingr.UUCP (Keith Ford x8614) writes: >>I have recently purchased 286-12MHz and 286-16MHz kits from Jameco >>Electronics. They are in a kit form, no soldering iron required. >>They have worked flawlessly! :) They use AMI (or was it Award?) >>BIOS and the 16MHz has the NEAT chipset. > >How much $ for one of these? Jameco is not cheap. I put together a few 12 MHz 286's for myself and some friends around a motherboard from Sys-Technology. For < $1250 I get a solid, no frills workhorse (albeit a little sluggish by today's 386 standards). 12 MHz 0 wait state 1 Mb ram 40 Mb (28 ms) HD 1:1 interleave controller 1.2 Mb FD mono graphics monitor/adapter 1 game port, 1 parallel, 2 serial ports case, 220 W supply, 101 Key keyboard. An identical system all from Jameco approaches $1600. Shop around and do it yourself. It's not as hard as you might think. - Stanton Loh u2zj@vax5.cit.cornell.edu