"xpyttl" wrote in message
...
Talk about bad timing ....

Just a couple of days ago two friends of mine hauled a PDP/8 out to the
dump. Of course, you might not have been able to afford the power to run
a
REAL PDP/8.

I never actually worked with an 8, although I did publish a paper on 11M
crash dump analysis. Might be fun to be able to grok a little Macro-11
from
time to time ... hmmm ... wonder if there's a Pro350, or even an old
11/44,
languishing in someone's basement.

..

"kenneth scharf" wrote in message
...
Does anybody know where I can get a Harris or Intersil
HD6100, HD6120, IM6100, or IM6120 microprocessor (cmos pdp-8)?

I used to work for Digital, and thought it would be an interresting
project
to homebrew a PDP-8 system. I have a T11 microprocessor chip in the
junbox
someplace, so a PDP-11 system is also a possibility.

Somewhere I have packed away a Sym-1 an Elf II and a Intersil 6100
familiarization board that had something like 256 bytes of ram, a boot rom
and a uart (the uart is farkled either the data out or data in line is bad
which is why I packed it away). I only have 25 more years till retirement,
so I may find time then to pull them out then and see if they still work. As
it is now I can't even find time to work on my remaining cp/m machines
(Xerox 820IIHD, RS 4p, Balcones BNV205, Osborne 1, Osborne Exec, and
Kaypro4).
thanks, John.
KC5DWD

"xpyttl" wrote in message
...
Talk about bad timing ....
I never actually worked with an 8, although I did publish a paper on 11M
crash dump analysis. Might be fun to be able to grok a little Macro-11
from
time to time ... hmmm ... wonder if there's a Pro350, or even an old
11/44,
languishing in someone's basement.

..

"kenneth scharf" wrote in message
...
Does anybody know where I can get a Harris or Intersil
HD6100, HD6120, IM6100, or IM6120 microprocessor (cmos pdp-8)?

I used to work for Digital, and thought it would be an interresting
project
to homebrew a PDP-8 system. I have a T11 microprocessor chip in the
junbox
someplace, so a PDP-11 system is also a possibility.

I don't know if you would be interested, but there have to still be a few
Heath LSI 11 systems out there. That was the only home version of the 11
that I know of.
thanks, John.

"xpyttl" wrote in message
...
Talk about bad timing ....
I never actually worked with an 8, although I did publish a paper on 11M
crash dump analysis. Might be fun to be able to grok a little Macro-11
from
time to time ... hmmm ... wonder if there's a Pro350, or even an old
11/44,
languishing in someone's basement.

..

"kenneth scharf" wrote in message
...
Does anybody know where I can get a Harris or Intersil
HD6100, HD6120, IM6100, or IM6120 microprocessor (cmos pdp-8)?

I used to work for Digital, and thought it would be an interresting
project
to homebrew a PDP-8 system. I have a T11 microprocessor chip in the
junbox
someplace, so a PDP-11 system is also a possibility.

I don't know if you would be interested, but there have to still be a few
Heath LSI 11 systems out there. That was the only home version of the 11
that I know of.
thanks, John.

kenneth scharf wrote in message
...
Does anybody know where I can get a Harris or Intersil
HD6100, HD6120, IM6100, or IM6120 microprocessor (cmos pdp-8)?

I used to work for Digital, and thought it would be an interresting
project
to homebrew a PDP-8 system. I have a T11 microprocessor chip in the
junbox
someplace, so a PDP-11 system is also a possibility.



In fact, there is a fellow who sells kits and parts for the SBC6120, which
is a build-your-own PDP-8 based on the IM6120 chip:

http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm

And this fellow has an add-on for the SBC6120:

http://www.jkearney.com/sbc6120/iob6120.htm

Also, IM6100 chips show up on eBay from time to time.

PDP-8 documentation may be found at Al Kossow's site:

http://www.spies.com/~aek/pdf/dec/pdp8/

And at Dave Gesswein's site:

http://www.pdp8.net

Also, Bob Supnik's SIMH retrocomputing simulator supports the PDP-8. SIMH
is hosted at Tom Shoppa's Trailing Edge site, currently down due to the
effects of Isabel:

http://simh.trailing-edge.com

To those of you who chuckle at the OP's questions, I've got a PDP-8/A
sitting about 5ft to my right as I type this, and a another in the basement,
right next to a PDP-8/E, a VT78 (based on the IM6100) and a DECmate II
(based on the IM6120). Just today I was at one place with a third PDP-8/A
which I refurbished a few months ago, a working PDP-8/E, a PDP-8/L in need
of serious help, 3 PDP-12s (essentially PDP-8/Is with added A/D and D/A
I/Os), several DECmates and a LINC-8. Today I also stopped by a place with
a several more DECmates and a PDP-8/L that I and a cohort rescued from the
defunct United Electronics tube factory in Newark, NJ this past spring.
PDP-8 Disease is incurable. Once infected you're happily chronic for life.

You can do an awful lot on a computer with only 8 instructions that can
directly address a mere 256 12-bit words at a time - if you're willing to
think a little bit. PDP-8s are to computers what regens are to radios:
Obsolete, but amazing for what they can do with so little, and a tremendous
pile of fun to play with. In essence they're the spirit of QRP operation as
applied to computers.

Geoffrey G. Rochat
Vice President, Rhode Island Computer Museum (www.osfn.org/ricm)
Member, RetroComputing Society of Rhode Island (www.osfn.org/rcs)

kenneth scharf wrote in message
...
Does anybody know where I can get a Harris or Intersil
HD6100, HD6120, IM6100, or IM6120 microprocessor (cmos pdp-8)?

I used to work for Digital, and thought it would be an interresting
project
to homebrew a PDP-8 system. I have a T11 microprocessor chip in the
junbox
someplace, so a PDP-11 system is also a possibility.



In fact, there is a fellow who sells kits and parts for the SBC6120, which
is a build-your-own PDP-8 based on the IM6120 chip:

http://www.sparetimegizmos.com/Hardware/SBC6120-2.htm

And this fellow has an add-on for the SBC6120:

http://www.jkearney.com/sbc6120/iob6120.htm

Also, IM6100 chips show up on eBay from time to time.

PDP-8 documentation may be found at Al Kossow's site:

http://www.spies.com/~aek/pdf/dec/pdp8/

And at Dave Gesswein's site:

http://www.pdp8.net

Also, Bob Supnik's SIMH retrocomputing simulator supports the PDP-8. SIMH
is hosted at Tom Shoppa's Trailing Edge site, currently down due to the
effects of Isabel:

http://simh.trailing-edge.com

To those of you who chuckle at the OP's questions, I've got a PDP-8/A
sitting about 5ft to my right as I type this, and a another in the basement,
right next to a PDP-8/E, a VT78 (based on the IM6100) and a DECmate II
(based on the IM6120). Just today I was at one place with a third PDP-8/A
which I refurbished a few months ago, a working PDP-8/E, a PDP-8/L in need
of serious help, 3 PDP-12s (essentially PDP-8/Is with added A/D and D/A
I/Os), several DECmates and a LINC-8. Today I also stopped by a place with
a several more DECmates and a PDP-8/L that I and a cohort rescued from the
defunct United Electronics tube factory in Newark, NJ this past spring.
PDP-8 Disease is incurable. Once infected you're happily chronic for life.

You can do an awful lot on a computer with only 8 instructions that can
directly address a mere 256 12-bit words at a time - if you're willing to
think a little bit. PDP-8s are to computers what regens are to radios:
Obsolete, but amazing for what they can do with so little, and a tremendous
pile of fun to play with. In essence they're the spirit of QRP operation as
applied to computers.

Geoffrey G. Rochat
Vice President, Rhode Island Computer Museum (www.osfn.org/ricm)
Member, RetroComputing Society of Rhode Island (www.osfn.org/rcs)

EGO was started by FHP engineers that declined to relocate, one of which was
me. The projects only became competitive after FHP moved to North Carolina
and expanded its objectives. The book is accurate on this point, and pretty
much everything else.

73,

Dave, AA6YQ

"John R. Strohm" wrote in message
...
"Dave, AA6YQ" wrote in message
news:lARab.522300$YN5.348403@sccrnsc01...
No cheating! If you're going to homebrew a PDP-8, you have to build it
out
of discrete TTL.

73,

Dave, AA6YQ
Data General, 1972 - 1981
Designer of the Nova 2, Nova 3, MP200, and microEclipse CPUs,
as
well as some parts of FHP and EGO

I thought FHP and EGO were completely separate, competing projects?
(Admittedly, my only source is Kidder's book.)

EGO was started by FHP engineers that declined to relocate, one of which was
me. The projects only became competitive after FHP moved to North Carolina
and expanded its objectives. The book is accurate on this point, and pretty
much everything else.

73,

Dave, AA6YQ

"John R. Strohm" wrote in message
...
"Dave, AA6YQ" wrote in message
news:lARab.522300$YN5.348403@sccrnsc01...
No cheating! If you're going to homebrew a PDP-8, you have to build it
out
of discrete TTL.

73,

Dave, AA6YQ
Data General, 1972 - 1981
Designer of the Nova 2, Nova 3, MP200, and microEclipse CPUs,
as
well as some parts of FHP and EGO

I thought FHP and EGO were completely separate, competing projects?
(Admittedly, my only source is Kidder's book.)

In the early/mid 60's the Science Club in my high school built a computer of
sorts out of salvaged telephone relays -- more of a binary adder than
anything else (sorry, I was too interested in 20 meters at the time!).

The Computer Museum is out in Mountain View California.

Jack
"Michael Black" wrote in message
...
"John R. Strohm" ) writes:
alt.sys.pdp8
alt.sys.pdp11
alt.sys.pdp10

"xpyttl" wrote in message
...
Talk about bad timing ....

Just a couple of days ago two friends of mine hauled a PDP/8 out to the
dump. Of course, you might not have been able to afford the power to
run
a
REAL PDP/8.

You do realize that there are people who collect these machines, and
have
been known to pay REAL MONEY for them, don't you???


A friend sold a PDP/8 on Ebay for around $3000 US (and since he's in
Canada,
it will be even better for him), just in July. It did have some odd
suffix
(and some oddity about the hardware to go with it), so I'm not sure it
that
drove the price up.

It was his first "home computer", and while he got a good deal on it (I
forget
the story, but I believe he bought it surplus in the seventies). He
was moving, so it seemed like a good time to clear it out.

Oddly, a couple of years ago I pointed him to someone periodically posting
in buy and sell newsgroups looking for such computers. When my friend
contacted him, the buyer was only willing to pay a few hundred dollars.

Sort of to get it back to amateur radio, most people know that Wayne Green
started BYTE, and then later Kilobaud. But in the November 1972 issue of
73 (the thickest up to that time), there was an article about building
your
own computer, from logic gates etc. It was not a construction article,
but
gave quite a bit of detail on what was needed for such a time and place.
Nobody ever seems to mention that article after the fact. I'm still
trying
to decide if the article had any bearing on how things went later. Did
Wayne
print it because he saw things going in that way, or did he just print
it as filler, yet when small computers came along a few years alter, it
helped to direct him to small comptuers?

Michael VE2BVW

In the early/mid 60's the Science Club in my high school built a computer of
sorts out of salvaged telephone relays -- more of a binary adder than
anything else (sorry, I was too interested in 20 meters at the time!).

The Computer Museum is out in Mountain View California.

Jack
"Michael Black" wrote in message
...
"John R. Strohm" ) writes:
alt.sys.pdp8
alt.sys.pdp11
alt.sys.pdp10

"xpyttl" wrote in message
...
Talk about bad timing ....

Just a couple of days ago two friends of mine hauled a PDP/8 out to the
dump. Of course, you might not have been able to afford the power to
run
a
REAL PDP/8.

You do realize that there are people who collect these machines, and
have
been known to pay REAL MONEY for them, don't you???


A friend sold a PDP/8 on Ebay for around $3000 US (and since he's in
Canada,
it will be even better for him), just in July. It did have some odd
suffix
(and some oddity about the hardware to go with it), so I'm not sure it
that
drove the price up.

It was his first "home computer", and while he got a good deal on it (I
forget
the story, but I believe he bought it surplus in the seventies). He
was moving, so it seemed like a good time to clear it out.

Oddly, a couple of years ago I pointed him to someone periodically posting
in buy and sell newsgroups looking for such computers. When my friend
contacted him, the buyer was only willing to pay a few hundred dollars.

Sort of to get it back to amateur radio, most people know that Wayne Green
started BYTE, and then later Kilobaud. But in the November 1972 issue of
73 (the thickest up to that time), there was an article about building
your
own computer, from logic gates etc. It was not a construction article,
but
gave quite a bit of detail on what was needed for such a time and place.
Nobody ever seems to mention that article after the fact. I'm still
trying
to decide if the article had any bearing on how things went later. Did
Wayne
print it because he saw things going in that way, or did he just print
it as filler, yet when small computers came along a few years alter, it
helped to direct him to small comptuers?

Michael VE2BVW

"Geoffrey G. Rochat" writes:
....[snip]....
You can do an awful lot on a computer with only 8 instructions that can
directly address a mere 256 12-bit words at a time - if you're willing to
think a little bit. PDP-8s are to computers what regens are to radios:
....[snip]....

You can also do an awful lot on a computer with only 8 instructions that
can directly address only THIRTY-TWO NINE-bit words at a time:

In 1969, while at Fairchild R&D Lab in Palo Alto, CA, I designed and
built a 9-bit PDP-8 imitation (I called it "MINUS", since it was smaller
than a mini-computer; if I had called it "MICRO", I might now be rich!)
with 512 9-bit words of 200 nsec memory. Its instruction format used
a: 3 bit opcode,
1 bit current page/page zero indicator,
1 bit indirect indicator, and a
4 bit address

I also wrote a cross-assembler (in FORTRAN) for it, interfaced it to a
20Kbyte/second magnetic tape and a 3-foot x 5-foot flat bed plotter,
and wrote a program (in MINUSASM) which, in a tight loop, read mag-tape
printed-circuit wirelists produced on an IBM 360/44, buffered them in
the upper half of memory, and then passed them to the plotter to draw
large PC boards. Just before quiting time, we'd load a new mag tape,
and 5-6 hours later another board had been drawn in three colors
(horizontal, vertical, and vias).

Ah, those were the heady days of youth!

--Myron A. Calhoun.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)