No sense in reviving old computers

philo wrote:
On 02/20/2017 11:15 PM, Mike S wrote:
On 2/20/2017 2:03 AM, Ant wrote:
Since we're talking about old school computers. Here are mine:
http://zimage.com/~ant/antfarm/about/toys.html ...

do you ever max out your 6GB RAM?




Speaking of maxing out RAM

about 12 years ago someone who was getting rid of junk gave me an ISA,
RAM extension board. I put it in my Zenith Data Systems 286 and got 16
megs of RAM recognized. The max amount a 286 can address!


At the time the machine was made 16 megs of RAM would have been (almost)
an impossibility and probably cost over $50,000

The RAM was probably bigger than the biggest disk drive
at the time :-)

Paul

On Tue, 21 Feb 2017 13:52:09 -0500, Paul
wrote:

philo wrote:

[snip]

At the time the machine was made 16 megs of RAM would have been (almost)
an impossibility and probably cost over $50,000

The RAM was probably bigger than the biggest disk drive
at the time :-)

Hardly. I bought a system (XT-compatible) with a 20 MB hard
drive in 1988. That was a run-of-mill size then.

Sincerely,

Gene Wirchenko

On 02/21/2017 12:52 PM, Paul wrote:
philo wrote:
On 02/20/2017 11:15 PM, Mike S wrote:
On 2/20/2017 2:03 AM, Ant wrote:
Since we're talking about old school computers. Here are mine:
http://zimage.com/~ant/antfarm/about/toys.html ...

do you ever max out your 6GB RAM?




Speaking of maxing out RAM

about 12 years ago someone who was getting rid of junk gave me an ISA,
RAM extension board. I put it in my Zenith Data Systems 286 and got 16
megs of RAM recognized. The max amount a 286 can address!


At the time the machine was made 16 megs of RAM would have been
(almost) an impossibility and probably cost over $50,000

The RAM was probably bigger than the biggest disk drive
at the time :-)

Paul



The machine came with 512k of on-board RAM. it was all discrete memory
chips . I'd have to look at it...but they were probably 10k or 20 k each

philo wrote:
On 02/21/2017 12:52 PM, Paul wrote:
philo wrote:
On 02/20/2017 11:15 PM, Mike S wrote:
On 2/20/2017 2:03 AM, Ant wrote:
Since we're talking about old school computers. Here are mine:
http://zimage.com/~ant/antfarm/about/toys.html ...

do you ever max out your 6GB RAM?




Speaking of maxing out RAM

about 12 years ago someone who was getting rid of junk gave me an ISA,
RAM extension board. I put it in my Zenith Data Systems 286 and got 16
megs of RAM recognized. The max amount a 286 can address!


At the time the machine was made 16 megs of RAM would have been
(almost) an impossibility and probably cost over $50,000

The RAM was probably bigger than the biggest disk drive
at the time :-)

Paul



The machine came with 512k of on-board RAM. it was all discrete memory
chips . I'd have to look at it...but they were probably 10k or 20 k each

The chips were all power-of-two, with values like 16Kx1, 16Kx4,
64Kx4, and so on. The older DRAM chips ran on three rails, whereas
static RAM only needed +5V. The DRAM chips also had an undershoot
problem, which meant if the waveforms wiggle just a little bit,
coming from the memory controller, it causes current to flow into
the substrate of the memory chip. The engineers hated this, because
basically every design they did was "tempting fate".

A significant change, is on one generation of memory, they removed
the hard clamp to ground, and the spec for the memory allowed
something like a 2V undershoot. This took a lot of pressure off the
poor guys still doing DRAM design. They could "almost relax".

If we fast forward to modern times, the designs don't have nearly
as much "drama" involved. I eventually did a design with DRAM,
and it... just worked. And I had practically nothing to do with
the success :-) On my design, the memory chips were soldered down
and not on a DIMM (like you might find on a tablet or
smart phone). If a board were to be tested and have "bad RAM", it
meant using the hot air station to replace it. All the first
batch of boards worked, and again, that's a testament to the
incoming quality of the memory we were buying. We didn't get
floor sweepings.

Paul

On 02/21/2017 09:48 PM, philo wrote:

[snip]

The machine came with 512k of on-board RAM. it was all discrete memory
chips . I'd have to look at it...but they were probably 10k or 20 k each

The computer I had that had 512KB on-board had 2 banks of 256Kb * 1
chips (18 RAM chips total, since 1 chip per bank was for parity).

Note the difference between bytes (B) and bits (b).

--
Mark Lloyd
http://notstupid.us/

"The state (the U.S. Constitution) has not the right to leave every man
free to profess and embrace whatever religion he may desire." [Pope Pius
IX]

On 02/21/2017 05:05 PM, Gene Wirchenko wrote:

[snip]

Hardly. I bought a system (XT-compatible) with a 20 MB hard
drive in 1988. That was a run-of-mill size then.

Yes. I got a 30MB, which was the same physical drive with a RLL
controller. It still allowed the user to do a low-level format (LLF).
IIRC, I would have to use DEBUG and give a command like GC000:00CC to
run a LLF program on the controller ROM.

Also, Spinrite could do a LLF.

Sincerely,

Gene Wirchenko



--
Mark Lloyd
http://notstupid.us/

"The state (the U.S. Constitution) has not the right to leave every man
free to profess and embrace whatever religion he may desire." [Pope Pius
IX]

On Sat, 18 Feb 2017 20:40:12 -0600, philo wrote:

On 02/18/2017 04:49 AM, Ant wrote:
sctvguy1 wrote:
On Thu, 16 Feb 2017 14:30:20 -0600, philo wrote:

On 02/15/2017 03:12 PM, Wildman wrote:
On Wed, 15 Feb 2017 21:53:38 +0100, Linea Recta wrote:

"philo" schreef in bericht
news I was given a 2ghz AMD machine with 2 gigs of RAM and a bad HD
with XP. In theory that should have been ok for Win7

I replaced the drive and installed Win7


The machine must have been 15 years old and though Win7 would
install, the CPU has no SSE2 so I was not able to install any new
browser due to lack of H/W support.

The machine has now been sent to the recycler



So it had an older processor than Pentium 4?

Intel started SSE2 with the P4 in 2001 but AMD did not support it
until the release of the Opteron and Athlon 64 chips in 2003.




Thanks for the info.

It did not break my heart to recycle a 16 year old comptuer

As long as it was not an IBM PS/2!

Why? I had my own PS/2 model 30 286 10 Mhz and a borrowed P70 386
portable back then. I hated Microchannel Architecture (MCA) in the 386.
286 was OK without its MCA, but dang slow.




My PS/2 runs win95 extremely well!

I am looking for a PS/2 to run OS/2. I am having a hard time finding on
in my area.