26 Jan
2001
26 Jan
'01
12:16 p.m.
From: Jerome Fine <jhfine(a)idirect.com>
I have been told that starting with V5.05, "the high priced spread" was
split onto 2 RL02 cartridges with each only slightly more than half
full.
Which versions of the RT-11 Source distribution do you
have? Also,
DEC internal copy of the source kit for 5.4. Nominally you could buy
a license for it at some really obcence price (more that 3000$). It
fills
the better part of one RL02.
I missed something - or I just don't understand
what you are getting at.
What was partitioned - RD52 or RL02 or a much bigger drive? And
I also don't know if "run" means "boot" or something else.
The RD52 into 3 10mb "RL02s" as virtual images.
I tried the TK50 - ONCE. Since I do a verify on any
backup tape 99%
of the time, anyone who has tried to do a BUP verify using a TK50
vs a hard disk will understand. While it took about 19 minutes to write
one 32 MByte RT-11 partition, it was over an hour during the
"/VERIFY:ONLY" operation that I gave up.
Now the TK70 (which uses the IDENTICAL DLT tape - CompacTape I)
is another matter. The TK70 drive writes 4 times as much data on one
tape and writes the data three time as fast and the "/VERIFY:ONLY"
operation is just as fast as the BACKUP. So a BUP with the TK70
can place 8.5 RT-11 partitions on one tape using a TK70.
Apparently a difference in how it handle streaming of small block sizes.
The TK50 does very poorly at writes of short blocks.
Reliable - yes. Useful as compared with 256 MBytes -
NO!
Well it doesnt require a SCSI board and I had it. If you have MO
Cool and all the better. If I had one I'd have used it.
But if you restrict the comparison to RD51,2,3,4
drives, then
yes!!!!!!!!!! I have had too many RD53 drives go in the last
few years to count. Most were Micropolis 1325 drives with
the R7 jumper inserted so that the RQDX2 thought they were
a real DEC RD53.
Which is a M1325! That drive was the poorest of the lot and
only a bit better than RD32 (ST251). The XT2190 (RD54) is a
good drive but like many of that type and size 31 Watts is a
lot of heat that is unhealthy over time. RD52 was the coolest
running of the pack and still fast for it size (and MFM).
But with Hitachi DK515-78 drives and a Sigma RQD11-EC
that handles four drives, there is not much to choose between
4 * RD52 (= 120 MBytes) and 4 * DK515-78 (=2.4 GBytes).
Killer if you have MSCP compatable SCSI, useless with the
more common RQDX3.
Now this is one area I would like to solve as well.
But what
OS is needed if I want to use the first 64 blocks on the CD?
With that many who cares? I'd just use it as an image copy of
the real thing. I'd have little interest in booting RT-11 from CD
as CDs most are slower than MFM! Also how would you handle
RT-11 SWAP.SYS? That has to be read/write.
Allison
26 Jan
26 Jan
1:30 p.m.
New subject: OT memory too cheap to pass up
I know this is off topic, but I figure some of you may not know how low
memory prices have dropped. I just bought a 256 MB stick of PC133 for $65,
with lots of other similar deals around. (now I just need a Tbird and a
KT133A chipset motherboard so I can speed around with it).
1:57 p.m.
New subject: OT memory too cheap to pass up
I know this is off topic, but I figure some of you may
not know how low
memory prices have dropped. I just bought a 256 MB stick of PC133 for $65,
with lots of other similar deals around. (now I just need a Tbird and a
KT133A chipset motherboard so I can speed around with it).
Thanks for making me even more depressed ($80 for 64MB of Mac FPM DIMMs). :-P
--
----------------------------- personal page: http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu
-- "I'd love to go out with you, but I'm stuck in the fourth lotus
position." -
2:59 p.m.
New subject: OT memory too cheap to pass up
I know this is
off topic, but I figure some of you may not know how low
memory prices have dropped. I just bought a 256 MB stick of PC133 for $65,
with lots of other similar deals around. (now I just need a Tbird and a
KT133A chipset motherboard so I can speed around with it).
Thanks for making me even more depressed ($80 for 64MB of Mac FPM DIMMs). :-P
3:34 p.m.
New subject: OT memory too cheap to pass up
Let me cheer you up, $515 for 128MB kit for an
AlphaStation 500/333, or
Sparc 5 RAM 32MB $50-100, or Sparc 20 RAM at about $1.50-2.00 per MB. Of
course it's the AlphaStation RAM I need the most followed by at least a
couple sticks of 64MB Sparc 20 RAM. BTW, the Sparc RAM prices listed above
take eBay into account on the low end! Then there is the 8MB VSIMM I want
for my Sparc 20, it's about $240.
Oh, I do sympathise :-) Remember the Apple Network Server that I was trying
to get parity FPM for? $500 for 64MB.
I'm going to throw in the towel and just stick non-parity in it. That's what
everyone seems to be doing these days with ANSes. But I would really love
that extra security that parity affords, unless someone wants to convince me
that parity is not all that useful in memory? (I'd love to be convinced since
you will save me around $300.)
--
----------------------------- personal page: http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu
-- "I'd love to go out with you, but I've dedicated my life to
linguini." -----
3:47 p.m.
New subject: OT memory too cheap to pass up
I'm going to throw in the towel and just stick
non-parity in it. That's
what everyone seems to be doing these days with ANSes. But I would
really love that extra security that parity affords, unless someone
wants to convince me that parity is not all that useful in memory? (I'd
love to be convinced since you will save me around $300.)
Hmmm... Buy nine modules, gut one module for chips, and solder those onto
the parity positions of the other eight modules?
27 Jan
27 Jan
7:21 a.m.
New subject: OT memory too cheap to pass up
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26 Jan
26 Jan
6:03 p.m.
New subject: OT memory too cheap to pass up
healyzh skrev:
> > I know this is off topic, but I figure some
of you may not know how low
> > memory prices have dropped. I just bought a 256 MB stick of PC133 for
> > $65, with lots of other similar deals around. (now I just need a Tbird
> > and a KT133A chipset motherboard so I can speed around with it).
>
> Thanks for making me even more depressed ($80 for 64MB of Mac FPM DIMMs).
> :-P
Let me cheer you up, $515 for 128MB kit for an
AlphaStation 500/333, or
Sparc 5 RAM 32MB $50-100, or Sparc 20 RAM at about $1.50-2.00 per MB. Of
course it's the AlphaStation RAM I need the most followed by at least a
couple sticks of 64MB Sparc 20 RAM. BTW, the Sparc RAM prices listed above
take eBay into account on the low end! Then there is the 8MB VSIMM I want
for my Sparc 20, it's about $240.
Of course I could also use some of the Mac DIMMs you
mention for my 8500/180,
since I use it for Audio work.
I'm almost tempted to pickup some PC133 RAM despite
the fact I don't need it
and stuff it in my G4/450 (already has 256MB). I could almost use it there
(Photoshop would like it) I don't have any use for more RAM in my Linux box.
Now, to make this on topic, there have been memory module converters before.
For the Amiga 3000, which used exotic ZIP (not the moderately common SIPP)
modules, there have been SIMM->ZIP converters for a long time. Our hardware
guy said he would try to build one for our next meeting, so that we may get
some use out of our newly-restored A3000. Similarly, it is possible to wire
72-pin SIMMs into 64-pin ones (used on GVP equipment and certain Macs and
addon boards). Why shouldn't it be possible to make SDRAM to SIMM adapters?
--
En ligne avec Thor 2.6.
optimus@dec:foo$ %blow
bash: fg: %blow: no such job
6:30 p.m.
New subject: OT memory too cheap to pass up
Now, to make this on topic, there have been memory
module converters before.
For the Amiga 3000, which used exotic ZIP (not the moderately common SIPP)
modules, there have been SIMM->ZIP converters for a long time. Our hardware
guy said he would try to build one for our next meeting, so that we may get
some use out of our newly-restored A3000. Similarly, it is possible to wire
Sure I've got one for my A3000, it was a lot cheaper than getting ZIP's.
72-pin SIMMs into 64-pin ones (used on GVP equipment
and certain Macs and
addon boards). Why shouldn't it be possible to make SDRAM to SIMM adapters?
ISTR, when the 72-pin SIMM's came out you could get converters to use your
old RAM, likewise you used to be able to get converters that would turn 4
1MB SIMMs into 1 4MB SIMM.
I don't know the techincal difficulties it would cause, but one problem I
see is the speed of the RAM. For example, I've got a HP5MP printer, it
takes 72-pin SIMMs. If you stick 60ns ones it, it won't be able to use
them, but it loves 70ns ones. Then there is the issue of supply and demand,
there just isn't the demand for such a product.
Zane
6:59 p.m.
New subject: OT memory too cheap to pass up
On Fri, 26 Jan 2001 healyzh(a)aracnet.com wrote:
SIMM stackers, yes. A shop which I frequent still has got them, but
nowadays 30-pin memory is as rare as hen's teeth, unless you're looking
for the 1 MB variety, but adding them up in order to create a dead-slow 4
MB high-rise 72-pin SIMM doesn't seem as the wise thing to do.
Now, to make
this on topic, there have been memory module converters before.
For the Amiga 3000, which used exotic ZIP (not the moderately common SIPP)
modules, there have been SIMM->ZIP converters for a long time. Our hardware
guy said he would try to build one for our next meeting, so that we may get
some use out of our newly-restored A3000. Similarly, it is possible to wire
Sure I've got one for my A3000, it was a lot cheaper than getting ZIP's.
72-pin SIMMs into 64-pin ones (used on GVP
equipment and certain Macs and
addon boards). Why shouldn't it be possible to make SDRAM to SIMM adapters?
ISTR, when the 72-pin SIMM's came out you could get converters to use your
old RAM, likewise you used to be able to get converters that would turn 4
1MB SIMMs into 1 4MB SIMM. I don't know the techincal difficulties it would
cause, but one problem I
see is the speed of the RAM. For example, I've got a HP5MP printer, it
takes 72-pin SIMMs. If you stick 60ns ones it, it won't be able to use
them, but it loves 70ns ones. Then there is the issue of supply and demand,
there just isn't the demand for such a product.
I think I'll have to go ask around on comp.sys.amiga.hardware or
comp.sys.atari.st.tech and see what the tech people say. I actually think
that there may be a certain demand, at least enough for some people to set
about creating some smaller batches. After all, how many of us aren't
using 72-pin systems?
Mind you, one problem is the ever-growing tangible size of memory modules.
How do you stuff a 14 cm long SDRAM module into a much smaller 72-pin
socket? Still, it's apparently possible to stuff 72 pins into 64.
Of course, with the blindeningly short access speeds of SDRAM, there may
be the possibility that this kind of RAM won't run at "normal" speeds
measured in tens of nanoseconds.
27 Jan
27 Jan
12:09 a.m.
New subject: OT memory too cheap to pass up
On 27 Jan 2001, Iggy Drougge wrote:
addon boards). Why shouldn't it be possible to
make SDRAM to SIMM adapters?
SDRAM, FPM, and EDO are types of dynamic RAM.
SIMM, DIMM, and SO-DIMM are types of memory card.
So I'm not sure what exactly you're asking. If you're talking about making
an adaptor to plug DIMMs with EDO or FPM on them (which are pretty rare
now) into a system designed for SIMM EDO or FPM RAM, that could probably
be done. If you're talking about making an adaptor for plugging DIMMs with
SDRAM on them into a system designed for SIMM EDO or FPM RAM, you're out
of luck unless you design a specialised memory controller to drive the
SDRAM signals (it can probably be done, but it'd take a lot of work). This
has been something of a problem in the embedded systems world because most
manufacturers have already stopped, or are planning to stop in the near
future, all production of EDO and FPM RAM. However there are a great deal
of embedded systems in production which have not been updated to use SDRAM
(to do so would frequently mean moving to a whole new processor
generation as older devices like the Z80 and 68000 family simply can't
drive SDRAM without a specialised and complex external SDRAM controller).
--
------- Alex Holden -------
http://www.linuxhacker.org/
http://www.robogeeks.org/
3:51 a.m.
New subject: OT memory too cheap to pass up
Alex Holden skrev:
On 27 Jan 2001, Iggy Drougge wrote:
> addon boards). Why shouldn't it be possible to make SDRAM to SIMM adapters?
SDRAM, FPM, and EDO are types of dynamic RAM.
SIMM, DIMM, and SO-DIMM are types of memory card.
Ahh. I don't own any computers with this kind of memory, so I've never managed
to learn the nomenclature.
So I'm not sure what exactly you're asking. If
you're talking about making
an adaptor to plug DIMMs with EDO or FPM on them (which are pretty rare
now) into a system designed for SIMM EDO or FPM RAM, that could probably
be done. If you're talking about making an adaptor for plugging DIMMs with
SDRAM on them into a system designed for SIMM EDO or FPM RAM, you're out
of luck unless you design a specialised memory controller to drive the
SDRAM signals (it can probably be done, but it'd take a lot of work). This
has been something of a problem in the embedded systems world because most
manufacturers have already stopped, or are planning to stop in the near
future, all production of EDO and FPM RAM. However there are a great deal
of embedded systems in production which have not been updated to use SDRAM
(to do so would frequently mean moving to a whole new processor
generation as older devices like the Z80 and 68000 family simply can't
drive SDRAM without a specialised and complex external SDRAM controller).
I'm also running a 68040 system as my main system, that's why I'm interested
in using this kind of memory.
I suppose this isn't like wiring a SIMM into a system built for DRAM
capsules, such as an Atari ST?
--
En ligne avec Thor 2.6.
Se pensate che alcune sigle dei cartoni in Italia siano bruttine, ascoltatevi
quella di Kenshiro in francese ("Ken le survivant")... Non saprei se sia pi?
trash questa o quella di Mazinga Z in Francese...
Nicola Solati om den franska signaturen till Hokut? no Ken
5:38 a.m.
New subject: OT memory too cheap to pass up
On 27 Jan 2001, Iggy Drougge wrote:
I suppose this isn't like wiring a SIMM into a
system built for DRAM
capsules, such as an Atari ST?
No, SDRAM is quite a different beast to "standard" DRAM (in terms of the
signals it uses, not just the package type).
--
------- Alex Holden -------
http://www.linuxhacker.org/
http://www.robogeeks.org/
26 Jan
26 Jan
11:58 p.m.
New subject: OT memory too cheap to pass up
On Fri, 26 Jan 2001 healyzh(a)aracnet.com wrote:
?18.64 per 512K SRAM chip for a prototype system I'm developing :(
--
------- Alex Holden -------
http://www.linuxhacker.org/
http://www.robogeeks.org/
Thanks for
making me even more depressed ($80 for 64MB of Mac FPM DIMMs). :-P
Let me cheer you
up, $515 for 128MB kit for an AlphaStation 500/333, or
7:36 p.m.
New subject: OT memory too cheap to pass up
memory prices
have dropped. I just bought a 256 MB stick of PC133 for $65,
Thanks for making me even more depressed ($80 for 64MB of Mac FPM DIMMs). :-P
8:51 p.m.
New subject: OT memory too cheap to pass up
On Fri, 26 Jan 2001, Mike Ford wrote:
You should have 3 Starmax mac clones of the Apple 4400 like I do, 64 MB of
3.3v unbuffered EDO 11 row refresh single bank is running about $150.
Well, perhaps I shouldn't pity myself for the high RAM prices - at least I
don't run memory hogs like MacOS. =)
memory prices have dropped. I just bought a 256 MB
stick of PC133 for $65,
Thanks for making me even more depressed ($80 for 64MB of Mac FPM DIMMs). :-P
27 Jan
27 Jan
6:50 a.m.
New subject: OT memory too cheap to pass up
Iggy Drougge wrote:
Well, perhaps I shouldn't pity myself for the high
RAM prices - at least I
don't run memory hogs like MacOS. =)
I think you'd best do a little studying as to why people put so much RAM in
thier Mac's. It's for the same reason that some people put that much in
thier PC's. It's not the OS, it's the Apps. When you're working with
50MB+ graphics files with multiple layers in Adobe Photoshop it helps to
have lots of RAM. The same thing is true if you're doing Audio (and I
would assume video work).
Zane
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh(a)aracnet.com (primary) | OpenVMS Enthusiast |
| healyzh(a)holonet.net (alternate) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
7:04 a.m.
New subject: OT memory too cheap to pass up
I think you'd best do a little studying as to why
people put so much RAM in
thier Mac's. It's for the same reason that some people put that much in
thier PC's. It's not the OS, it's the Apps. When you're working with
50MB+ graphics files with multiple layers in Adobe Photoshop it helps to
have lots of RAM. The same thing is true if you're doing Audio (and I
would assume video work).
Yep. I have 128MB in my 7300, which is not enough because I have to turn
virtual memory off to get good video throughput from the capture board. I do
a lot of multimedia work on it. 256MB would be better if the price point
weren't as prohibitive as it is.
--
----------------------------- personal page: http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu
-- Wagner's music is better than it sounds. -- Mark Twain ---------------------
7:17 a.m.
New subject: OT memory too cheap to pass up
It's only a matter of time before the norm will be a GB of cache and half a
TB of DRAM ... and, of course, 768 TB of HD space. <sigh> now if we could
just get the software folks to leave out what's not necessary, including the
bugs.
Dick
----- Original Message -----
From: "Cameron Kaiser" <spectre(a)stockholm.ptloma.edu>
To: <classiccmp(a)classiccmp.org>
Sent: Saturday, January 27, 2001 11:04 AM
Subject: Re: OT memory too cheap to pass up
do
> I think you'd best do a little studying as to
why people put so much RAM
in
thier
Mac's. It's for the same reason that some people put that much in
thier PC's. It's not the OS, it's the Apps. When you're working with
50MB+ graphics files with multiple layers in Adobe Photoshop it helps to
have lots of RAM. The same thing is true if you're doing Audio (and I
would assume video work).
Yep. I have 128MB in my 7300, which is not enough because I have to turn
virtual memory off to get good video throughput from the capture board. I a lot of multimedia work on it. 256MB would be better
if the price point
weren't as prohibitive as it is.
--
----------------------------- personal page:
http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University *
ckaiser(a)stockholm.ptloma.edu
-- Wagner's music is better than it sounds. --
Mark
Twain ---------------------
9:21 a.m.
New subject: OT memory too cheap to pass up
Richard Erlacher wrote:
It's only a matter of time before the norm will be
a GB of cache and half a
TB of DRAM ... and, of course, 768 TB of HD space. <sigh> now if we could
just get the software folks to leave out what's not necessary, including the
bugs.
Dick
Sorry Dick, that wouldn't fit the bottom line. Business reasons, you know. What
they get paid to do.
-- John Tinker
9:55 a.m.
New subject: OT memory too cheap to pass up
Zane H. Healy skrev:
Iggy Drougge wrote:
>Well, perhaps I shouldn't pity myself for the high RAM prices - at least I
>don't run memory hogs like MacOS. =)
I think you'd best do a little studying as to why
people put so much RAM in
thier Mac's. It's for the same reason that some people put that much in
thier PC's. It's not the OS, it's the Apps. When you're working with
50MB+ graphics files with multiple layers in Adobe Photoshop it helps to
have lots of RAM. The same thing is true if you're doing Audio (and I
would assume video work).
Yoo ain't foolin' me, boy. How else would you explain that my IIci immediately
recognised the 16 MB I added into it (before, it had only run on 8), and
immediately found a way for the OS to take over the absolute majority of that
memory, leaving me with about as much (little) free memory as before.
--
En ligne avec Thor 2.6.
Test makers do it sometimes/always/never.
1 p.m.
New subject: OT memory too cheap to pass up
Yoo ain't foolin' me, boy. How else would you
explain that my IIci
immediately
recognised the 16 MB I added into it (before, it had
only run on 8), and
immediately found a way for the OS to take over the absolute majority of that
memory, leaving me with about as much (little) free memory as before.
Without 32-bit addressing enabled, the MacOS can only access 8 MB RAM.
Anything more is reported as being used by the system.
You need to switch from 24-bit to 32-bit addressing in the Memory control
panel.
Tom
Applefritter
www.applefritter.com
2:03 p.m.
New subject: OT memory too cheap to pass up
On Sat, 27 Jan 2001, Tom Owad wrote:
Ah, bollocks, I thought I had solved that by using a IIci, which is 32-bit
clean.
Yoo ain't
foolin' me, boy. How else would you explain that my IIci
immediately
recognised the 16 MB I added into it (before, it
had only run on 8), and
immediately found a way for the OS to take over the absolute majority of that
memory, leaving me with about as much (little) free memory as before.
Without 32-bit addressing enabled, the MacOS can only access 8 MB RAM.
Anything more is reported as being used by the system. You need to switch from 24-bit to 32-bit addressing in
the Memory control
panel.
I see now that it was turned to 24-bit, right. The 4-meggers have found a
new home now, though. =)
1:46 p.m.
New subject: OT memory too cheap to pass up
Yoo ain't foolin' me, boy. How else would you
explain that my IIci immediately
recognised the 16 MB I added into it (before, it had only run on 8), and
immediately found a way for the OS to take over the absolute majority of that
memory, leaving me with about as much (little) free memory as before.
Because, IIRC, the MacOS kernel is partially compressed and uncompresses
itself to whatever amount will comfortably fit in memory (at least in System
7). When I had 4MB in my IIsi, MacOS took up 2.2MB. When I had eight, it went
to 3.9. This also accounts for the speed increase you see by stuffing more
memory into older Macs (observations made on System 7.1.2).
--
----------------------------- personal page: http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu
-- "I'd love to go out with you, but the doorjambs need dusting."
-------------
26 Jan
26 Jan
9:25 p.m.
New subject: OT memory too cheap to pass up
bitch, bitch, bitch. I dare you to find a MS690 128MB memory for less than
$900 retail :-)
Seriously though, a way cool classic hack would be a memory card for the
VAX that took "modern" SIMMs or DIMMs.
--Chuck
9:31 p.m.
New subject: OT memory too cheap to pass up
Seriously though, a way cool classic hack would be a
memory card for
the VAX that took "modern" SIMMs or DIMMs.
I've been thinking about building an SBI memory card for the VAX-11/785.
They can access a maximum of 512MB physical, so I'd probably use two
256M SDRAM DIMMs.
But somehow I imagine that's not what you're looking for. :-)
Any idea how much memory a KA655 can support? I've got three 16MB cards
on it now, but I wonder how many address lines they brought out. It's
a bummer that the KA630 is limited to 16MB.
9:54 p.m.
New subject: OT memory too cheap to pass up
At 12:31 AM 1/27/01 -0800, you wrote:
I've been thinking about building an SBI memory
card for the VAX-11/785.
They can access a maximum of 512MB physical, so I'd probably use two
256M SDRAM DIMMs.
That would be interesting. You could use duct tape to attach a soldering
iron to the board so it would generate the same heat that 512MB does :-)
Any idea how much memory a KA655 can support? I've
got three 16MB cards
on it now, but I wonder how many address lines they brought out. It's
a bummer that the KA630 is limited to 16MB.
KA655, from the manual will support a maximum of 64MB of ECC RAM. (and it
does too since my 3800 has 64MB in it)
--Chuck
27 Jan
27 Jan
7:56 a.m.
New subject: OT memory too cheap to pass up
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8:43 a.m.
New subject: OT memory too cheap to pass up
Tony Duell wrote:
[snip]
I believe the original IBM PC/AT had a resistor unit
that was screwed to
the chassis and connected to a drive power cable if there wasn't a hard
disk installed. I think it was a load on the 12V power line, which was
otherwise too lightly loaded (no hard disk spindle motor) to behave
properly. I've never seen this device, and it's not shown in the techref
(only in the HMS manual), so I can't be sure.
It decidedly existed. The first AT I owned arrived sans hard disk; when I
went to install same I just about fell over laughing when I found the
load resistor -- mounted on a purpose-built bracket that both
increased dissipation as well as fit nicely into the mount for the full-height
MFM drive ;-)
-ck
--
Chris Kennedy
chris(a)mainecoon.com
http://www.mainecoon.com
PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97
9:13 a.m.
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12:16 p.m.
New subject: OT memory too cheap to pass up
Tony Duell wrote:
[snip]
What I have never managed to find out (and if anyone
here knows, please
let us all know) is (a) what power line this resistor loads (it has to be
either +5V or +12V as it connects to a drive power connector) and (b)
what is the resistance (and wattage) of this resistor.
Caution: What follows is from memory which is increasingly subject to
bit rot.
My recollection was that it loaded the 12V line, not the 5V line. I
don't recall the value nor the rated wattage, but it was packaged
in the finned metal package (as opposed to ceramic) that I generally
associate with things dissipating above 5W -- and it was sporting
heat sink compound between it and the cage, suggesting that there
was at least an attempt being made to dump heat into the rest of the
chassis.
I'm not sure how essential it is either. Certainly
most PC/AT PSUs don't
like running with no load (they trip, they don't fail permanently), but
in my experience only the 5V line needs to be loaded, and the motherboard
will do that. Certainly I've run PC/AT machines without a hard disk and
without this load resistor.
As have I (that machine, in fact). My assumption was that it simply represented
conservative design on the part of IBM to avoid the 12V supply becoming
unloaded when the floppy wasn't running.
-ck
--
Chris Kennedy
chris(a)mainecoon.com
http://www.mainecoon.com
PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97
4:34 p.m.
New subject: OT memory too cheap to pass up
At 08:13 PM 1/27/01 +0000, you wrote:
I have a resistor like that that I found in a HP PC clone expansion
chassis. I don't know the values off hand but I can dig it out and find
out. I saved the resistor to use as a dummy load for testing power supplies.
Joe
Tony Duell wrote:
[snip]
I don't doubt it existed. It's shown in the Hardware Maintenance and
Service manuals (if you're wondering why I have those board-swapper
guides, it's because I was given them when I bought a second-hand set of
TechRefs...).
What I have never managed to find out (and if anyone here knows, please
let us all know) is (a) what power line this resistor loads (it has to be
either +5V or +12V as it connects to a drive power connector) and (b)
what is the resistance (and wattage) of this resistor. I believe the original IBM PC/AT had a resistor
unit that was screwed to
the chassis and connected to a drive power cable if there wasn't a hard
disk installed. I think it was a load on the 12V power line, which was
otherwise too lightly loaded (no hard disk spindle motor) to behave
properly. I've never seen this device, and it's not shown in the techref
(only in the HMS manual), so I can't be sure.
It decidedly existed. The first AT I owned arrived sans hard disk; when I 
2:19 a.m.
New subject: OT memory too cheap to pass up
Seriously though, a way cool classic hack would be a
memory card for
the VAX that took "modern" SIMMs or DIMMs.
I've got a Dataram DR224 8MB memory upgrade for the Digital
MicroVAX and
MicroVAX II. It is populated with 288 ZIPs (M5M4256L-150). I hate
to even think how big a pain it would've been to insert those ZIPs if
they had been socketed! I remember the hassle involved in upgrading
them in my A3000 a few years ago. According to Dataram, this board
was manufactured somtime in '86.
Jeff
--
Collector of Classic Microcomputers and Video Game Systems:
Home of the TRS-80 Model 2000 FAQ File
http://www.geocities.com/siliconvalley/lakes/6757
2:09 a.m.
New subject: OT memory too cheap to pass up
memory prices have dropped. I just bought a 256 MB
stick of PC133 for $65,
Thanks for making me even more depressed ($80 for 64MB of Mac FPM DIMMs). :-P 
26 Jan
26 Jan
4:17 p.m.
New subject: OT memory too cheap to pass up
On Fri, 26 Jan 2001, Mike Ford wrote:
p.p.s. That's with a Cooler Master DP5-6H11 15cfm fan and heatsink.
jbdigriz
6 p.m.
New subject: OT memory too cheap to pass up
Mike Ford skrev:
I know this is off topic, but I figure some of you may
not know how low
memory prices have dropped. I just bought a 256 MB stick of PC133 for $65,
with lots of other similar deals around. (now I just need a Tbird and a
KT133A chipset motherboard so I can speed around with it).
Whereas those of us still using SIMMs are left stranded. I've found that
buying entire machines just for their memory is now cheaper than buying the
SIMMs separately.
--
En ligne avec Thor 2.6.
"LART is an acronym for Luser Attitude Readjustment Tool, and is generally a
piece of heavy hard material such as a cricket or baseball bat, hunk of pipe,
or 2x4 for the fine tuning of a luser's atitude. This is a noun that can be
used as a verb. If I say I lart someone, I mean that I am performing delicate
tuning procedures upon that persons head utilizing a LART. An ICBM would be
considered an agressive LART."
6:34 p.m.
New subject: OT memory too cheap to pass up
At 06:00 AM 1/27/01 +0100, Iggy wrote:
Whereas those of us still using SIMMs are left
stranded. I've found that
buying entire machines just for their memory is now cheaper than buying the
SIMMs separately.
This has got to be one of the principles of collecting, complete machines
are cheaper than the parts. When I do this with a VAX I call it "VAX
mining." You get 6 tons of non-working VAX equipment for free and then you
put together working systems out of the parts and sell or give away the
extra pieces. The first two MicroVAX IIs that I bought (non-working/no
drives) had RQD11/E ESDI controllers in them. Replace the drives and voila,
nice systems once again.
--Chuck
2:02 p.m.
With that many who cares? I'd just use it as an
image copy of
the real thing. I'd have little interest in booting RT-11 from CD
as CDs most are slower than MFM! Also how would you handle
RT-11 SWAP.SYS? That has to be read/write.
Allison
The key thing with a CD is that you can boot off of CD long enough to
restore your system if you loose a HD, or you can restore files off of one
of the partitions on the CD.
My MutantPDP-11/73 uses a Viking SCSI Controller, and on that I've got a
RRD42 CD-ROM, TZ30, and two 100MB SCSI HD's in removable trays. I can pull
the trays out and stick different ones in if I want to run a different OS,
or I can put them into a bay on my Linux box and 'dd' them to an image file
that can then be FTP'd to my Mac and copied to a CD-R.
I like this as I feel a *lot* safer having the data on CD-R than I would
having the data on magnetic media.
Zane
8558
days inactive
8559
days old
38 comments
16 participants
participants (16)
-
ajp166＠bellatlantic.net -
alex＠linuxhacker.org -
ard＠p850ug1.demon.co.uk -
chris＠mainecoon.com -
cmcmanis＠mcmanis.com -
edick＠idcomm.com -
eric＠brouhaha.com -
healyzh＠aracnet.com -
jbdigriz＠dragonsweb.org -
jhellige＠earthlink.net -
jtinker＠coin.org -
mikeford＠socal.rr.com -
optimus＠canit.se -
owad＠applefritter.com -
rigdonj＠intellistar.net -
spectre＠stockholm.ptloma.edu