Netronix Elf II on eBay

Martin_H

Back in the day I wanted one of these, but couldn't afford one. Now they're collector's items and this one is well on it's way to fetching a high price:

http://www.ebay.com/itm/201921197815?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

MikeDYur

Isn't this lower or around it's original price?

You really have to have a passion for wanting what would be considered an antique. I always wanted to go back, just wonder how long the novelty will last.

If I owned this, the first thing that would go is that vintage particle board. That is one thing I don't want to revisit.

DaveJenson

Ah. History! The Signetics 1802 processor was one of the first ones I played with back in the day. You could clock it with a toggle switch! Which worked great for debugging simple assembly code.

Now I see the chips available on eBay for $8 and up.

Martin_H

MikeDYur wrote: »

Isn't this lower or around it's original price?

You really have to have a passion for wanting what would be considered an antique. I always wanted to go back, just wonder how long the novelty will last.

They were $100 as a kit and $150 assembled. Given 40 years of inflation that would be around $400 in today's dollars.

MikeDYur

Martin_H wrote: »

They were $100 as a kit and $150 assembled. Given 40 years of inflation that would be around $400 in today's dollars.

It certainly would be a nice addition to someones collection, if only because of the processors history in space.

Space Technology and Science Edit
The 1802 was used in many spacecraft and space science programs, experiments, projects and modules.

The Galileo spacecraft used multiple (~20) 1802 microprocessors.[10]
The 1802 has often been incorrectly claimed to have been used in the earlier Viking and Voyager spacecraft, but it was not available at the time those spacecraft were being designed, and primary sources describe the Viking and Voyager computers as having architectures very dissimilar to the 1802, and not being microprocessor-based.[11]
The 1802 has been widely used in Earth-orbiting satellites, mainly for their primary computer, but since the 1990s its use as a low complexity flight control and telecom systems computer has dominated.[12]
AMSAT's Phase 3-D (aka AO-40, probably the last 1802 launched into Space in 2000)[13]
Various OSCAR satellites[14]
UoSAT-C[15]
UoSAT-1 UO-9
MAGSAT
The two-chip 1801 predecessor to the 1802 was used in earlier AMSAT satellites.[16]
The 1802 has also been verified from NASA source documentation to have been used in:
The Hubble Space Telescope
Magellan Venus probe
Ulysses spacecraft
The 1802 was also used in MASCOT (MIT Astronomical Spectrometer/Camera for Optical Telescopes), a traveling instrument deployed on many telescopes in the early 1980s.[17][18]
At least one of the 57 experiments aboard NASA's Long Duration Exposure Facility (LDEF) space experiment module (launched and retrieved by Space Shuttles), the Thermal Control Surfaces Experiment (TCSE), used the 1802.
An 1802-based security device, the Electronic Fill Device, was used in conjunction with the U.S. Space Shuttle's Secure Communications System, as a ground-based Encryption/Decryption system to load top secret mission keys on several Shuttle and ground computer systems before launch.[19]
The Indian Space Research Organisation (ISRO) SROSS-C and SROSS-C2 satellites launched in 1992 and 1994, respectively, used an 1802 processor.[20] It is unknown whether the two earlier satellites that failed to launch (A & incorporated an 1802.

erco

Related, but older "vintage" technology in my collection:

I still have one of these way-old Western Union Desk Faxes stored in my attic: http://blog.modernmechanix.com/desk-size-facsimile-machine/

Exactly as the commenter says, my brother and I got these from a hamfest or flea market 40 years ago for a pittance. The ARRL manual showed how to replace the incandescent light & photocell with a phototransistor, which we did. We only had Novice tickets so we couldn't use them on the air, but I did many cool experiments. We sent a dollar bill over a phone line, from one machine to the other. My 11th grade science fair experiment was "Light Beam Communications", for which I built many seperate projects. I built Forest Mims' light beam communicator from Radio Shack mini-books, which let me send voice over an IR beam. Then I sent a fax to myself (only had my machine). I had "recorded" the fax machine's audio output as it scanned a dollar bill to a cassette tape recorder. Then I played it back while sending it over the light beam communicator to the same fax machine and printed it out. Oh, and I made my own electrostatic fax paper (electric needle stylus darkens paper) from tincture of iodide, had to research how to do that.

And yeah, I won first place at the school and county science fairs, and a citation & award dinner from the Optical Society of America.

Tor

There is apparently an ELF hoarder out there who buys up all and every ELF he can get his hands on, outbidding everyone else. Not particularly nice. So if I were to get an ELF I would buy a reasonably priced 1802 from ebay (I actually have a couple in a drawer so I don't have to), and build a clone (a modern one).

Peter Jakacki

DaveJenson wrote: »

Ah. History! The Signetics 1802 processor was one of the first ones I played with back in the day. You could clock it with a toggle switch! Which worked great for debugging simple assembly code.

Now I see the chips available on eBay for $8 and up.

Did you mean the Signetics 2650? It was noted for its static clocking ability at a time when CPUs had minimum clock rates specified. I saved up all my hard earned cash and placed an order for not just any evaluation board, I had to have the best, all 1K RAM of it too!

MikeDYur

Here's is my entry for one board computers:
at least I have the same processor.

https://en.m.wikipedia.org/wiki/MK14

Bucket list: Get this processor running on it's evaluation board.

The SC/MP from National Semiconductor is an early microprocessor, which became available in early 1974. The name SC/MP (pronounced "Scamp") is an acronym for: "Simple Cost-effective Micro Processor".

It features a 16-bit address and an 8-bit data bus. The program counter will roll-over on 12-bits (4096), there are separate instructions to alter the program counter to set the upper 4-bits, which are subsequently output on the address bus along with status signals. This provides a memory map of 16 pages each of 4 KB. Internally it provided five registers plus the program counter, but no stack pointer.

MikeDYur

erco wrote: »

Related, but older "vintage" technology in my collection:

I still have one of these way-old Western Union Desk Faxes stored in my attic: http://blog.modernmechanix.com/desk-size-facsimile-machine/

The man I worked for in a TV shop had one, he showed it to me working. The aluminized paper comes in contact with the stylus and you see a little sparking and burning, smoke and a unique smell.

He was a ham, you guys experiment with all that kind of stuff.

localroger

I have a Quest Super ELF which was given to me by the older student who had built it in the early 1980's; he was on to more serious computers by then. This was the immediate successor to the ELF II introduced around 1978. The original owner had removed the two 512 byte x 4 bit RAM chips to install an unwieldy hand-wired 2K expansion RAM, which had become very flaky due to oxidization on the card edge connector. By the time I got it single-chip 2K x 8 bit RAM chips were available and I deadbug-wired one to the backside of the PCB, so that except for the two empty sockets the hack wouldn't be obvious from topside. It all still works to this day. About fifteen years ago an artsy type person owed me a favor and I had it framed.

MikeDYur

(deleted)

MikeDYur

You know the name was so familiar, but I don't remember ever seeing one or reading about it.
RCA, whoodathunk.

BTW: Things were happening so fast back then.

Martin_H

Tor wrote: »

So if I were to get an ELF I would buy a reasonably priced 1802 from ebay (I actually have a couple in a drawer so I don't have to), and build a clone (a modern one).

There's a modern clone called the membership card that fits in an Altoids tin. But that's too easy for my tastes. All the construction articles from the late 70's are online, as well as schematics for the improvements, and PCB artwork for the ELF II. If I was going to build one I would wire wrap it. They're much simpler to build than just about any other ROMless eight bit computer.

KeithE

Martin_H wrote: »

Tor wrote: »

So if I were to get an ELF I would buy a reasonably priced 1802 from ebay (I actually have a couple in a drawer so I don't have to), and build a clone (a modern one).

There's a modern clone called the membership card that fits in an Altoids tin. But that's too easy for my tastes. All the construction articles from the late 70's are online, as well as schematics for the improvements, and PCB artwork for the ELF II. If I was going to build one I would wire wrap it. They're much simpler to build than just about any other ROMless eight bit computer.

It looks like a nice kit - http://www.sunrise-ev.com//membershipcard.htm

Could always get one for reference, and then DIY one. I'm surprised that my father didn't have an Elf at some point. He must have missed out on it.

KeithE

Someone could do a MOnSter 1802 based on http://www.visual6502.org/wiki/index.php?title=RCA_1802E but it appears to have about 40% more transistors than the 6502. And the statement "The design is much more asynchronous than the 6502 or any of the later CPUs" is a little scary. Maybe one should cheat a little for things like registers and use something a bit more integrated than discrete transistors? Is there anyone out there crazy enough?

Peter Jakacki

I'd like to encapsulate an FPGA into a 40-pin DIP and then call it whatever I like, a 6502, an 1802, a Z80, 6809, 2650, or a P8X32C etc. Yeah, now we're talking!

Hal Albach

My first computer was also a Netronics Elf, to which I added a modified 5" TV as a monitor and a S100 8K ram card that had 64 2102 1K x 1 memory chips. Adapting the S100 interface to the Netronics bus proved challenging but worked in the end. Also added two Radio shack cassette recorders for mass storage which worked quite well. The largest program I ever wrote for the Elf was Conway's Game of Life, done completely in machine language since an assembler was not available at the time.
One of the unique features of the 1802 was the bank of 16, 16-bit directly addressable registers, any one of which could be a stack pointer. I also modified the main board by removing the two seven segment displays and replaced them with TIL311 BCD displays, which really made it easier to read the codes.
If memory serves me correctly, I think I paid $79 for it, from an ad in Byte Magazine.
Then I got an Atari 800...

DaveJenson

Peter Jakacki wrote: »

Did you mean the Signetics 2650? It was noted for its static clocking ability at a time when CPUs had minimum clock rates specified. I saved up all my hard earned cash and placed an order for not just any evaluation board, I had to have the best, all 1K RAM of it too!

Memory is the first thing to go! Yes of course the Signetics 2650!

MikeDYur

If someone wants to go retro, what are the best components to use?

1. Front panel LED indicators: ( quality, long life diffused, bright red, green, yellow.)

2. LED holders, not the usual run of the mill, (better than the cheep plastic ones, but less than the bulky metal ones.)

3. Mini toggle switches, ( quality, long life, positive action.)

When I do this, I want to do it right. I will more than likely build in a small cabinet, so confined space is going to make repairs difficult. A burnt out LED or broken toggle is not something I will want to deal with.

Can anyone please throw some names at me,

keep it clean!

BTW: I should have specified that I was looking for manufacturers, sorry.

Martin_H

KeithE wrote: »

Someone could do a MOnSter 1802 based on http://www.visual6502.org/wiki/index.php?title=RCA_1802E but it appears to have about 40% more transistors than the 6502. And the statement "The design is much more asynchronous than the 6502 or any of the later CPUs" is a little scary. Maybe one should cheat a little for things like registers and use something a bit more integrated than discrete transistors? Is there anyone out there crazy enough?

The prototype for the 1802 was built using discrete 7400 series chips and called the System 00. It has enough blinkenlights and toggle switches that give it PDP-8 level of nerd appeal.

Here's a picture of it: http://www.cosmacelf.com/gallery/system-00.html

You could build one out of discrete transistors, but there's a high bar to clear.

Martin_H

MikeDYur wrote: »

If someone wants to go retro, what are the best components to use?

1. Front panel LED indicators: ( quality, long life diffused, bright red, green, yellow.)

2. LED holders, not the usual run of the mill, (better than the cheep plastic ones, but less than the bulky metal ones.)

3. Mini toggle switches, ( quality, long life, positive action.)

The LED displays are either holes drilled in the aluminum face plate or smoked acrylic to let the LED's on the circuit board show through. I'd go amber, but that's just personal preference.

The front panel switches are either mini toggle switches or hex keypads. A hex keypad can be built using a key matrix, a MM74C922, and 74C173 latch. It's much more usable but evokes that Heathkit H8 or Elf II aesthetic.

https://en.wikipedia.org/wiki/Heathkit_H8#/media/File:Heathkit_H-8_computer.jpg

RS_Jim

The front panel switches are either mini toggle switches or hex keypads. A hex keypad can be built using a key matrix, a MM74C922, and 74C173 latch. It's much more usable but evokes that Heathkit H8 or Elf II aesthetic.

My first computer was an H-8, with 8K static ram. I used it for many years through many upgrades including128K bank switched dynamic ram, 2 disc controllers, 1 hard sector floppy and 1 soft sector, a game controller and a home-built controller for the X-Ten remote system. With that setup, I taught myself Z-80 assembler and control systems. At 1 point I wrote a Z80 task rotator that ran 6 independent tasks. Switching tasks saved all registers including PC and stack pointer. OBTW it all fit in an 8K EEPROM. The company that I developed it for decided they wanted it written in C and I was taken off of the project. (I still haven't learned C) They could never get it t work in C and eventually dropped the project.
Jim

blittled

Two years ago I did a favor for a friend and he was cleaning out an antique computer collection so he gave me a Netronix Elf II without the COSMAC 1802 chip. I happened to pick up 2 COSMAC Elf 1802's on the junk table at one of OBC's expos. I haven't got a good power supply for it but if I can get it working maybe I'll get $500 on ebay .

Actually I'll keep it for nostalgic reasons. As a teenager I picked up the Popular Electronics Issue with the Elf computer and REALLY wanted to build it but I didn't have the pocket change to buy the parts.