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Intel Intellec 8 MCS

Roland Huisman

Roland Huisman

Veteran Member
Joined
Mar 24, 2011
Messages
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Location
The Netherlands
So where do I post this one? Can I call it pre Altair?

Intel Intellec 8 - 1.jpgIntel Intellec 8 - 2.jpgIntel Intellec 8 - 3.JPGIntel Intellec 8 - 4.JPGIntel Intellec 8 - 5.jpg

I've picked it up this evening. I've really no idea about any prices for these things.
But I think 25 euro for the machine and 5 euro for the documentation was just a 'give away'
So I gave the man 50 euro's, really he was surprised :) The thing really looks like new.

The machine seems to work. I have to figure out what kind of cards are inside.

I wonder were there any floppy interfaces for these computers? I have no idea about the
amount of memory and what OS I can run on it. But I really like the machine. A lot to explore :)

Regards, Roland
 
Good find!

There is a floppy interface available for it--as I recall, it's a pair of boards, one of which (the digital board) has Intel 3000-series bit-slice logic on it.

Bitsavers has a ton of information on this thing.
 
Hello Chuck,

Thanks for your reply. I found some documents at bitsavers that I already have.
Where do you find the floppy documentation? I could not find it.

Regards, Roland
 
Hi
I think Chuck is thinking about the MSD800's. I don't recall
the MCS8 having anything other than a serial interface for a teletype.
And, yes, even 50 Euro was a steal. I would love to have one myself.
I don't believe a OS was ever created for MCS8. I do recall it
came with either a 8008 or a 8080 depending on the processor
board installed.
It had a simple monitor that could be used through the serial port
to load memory, read memory and program eproms ( 1702A and possible
2708 with the right programmer cards ).
It may have had a simple assembler in ROM but I don't recall.
It would be good to get dumps of the eproms in the machine but I
suspect they are either 1702As or 2708s that can not be read on
typical 5 volt only programmers without an adapter and sower supply.
I'd be interested in a list of boards. Intel put labels on them as a general
rule.
Dwight
 
Dwight is correct--sort of.

CP/M was developed by Gary Kildall on the Intellec-8, but he used a one-off controller designed by John Torode--and not from Intel. So, yes there was a disk controller for the Intellec-8, but you can't have it.

The two-board affair that I was talking about is indeed the one for the MDS-800.

Thanks for jogging my memory, Dwight.
 
Hello Dwight and Chuck,

Thanks for the information!

I was wondering if there is any information about that controller in that time.
But even if I had the controller, I think it is impossible to find the CP/M version.

Are there many of these computers? The serial is 199, so not very high I think.
The proms are all 1702A versions.

Regards, Roland
 
I think Herb Johnson has some information on his retrotechnology site. A simple site search on Torode should bring it up. Or just a general search web-wide for "Kildall Torode".

None of the Intel development systems was particularly common, but Intellec 8 hosted both 8008 and 8080 CPUs, so it may be easier to find than, say, an Intellec 4. Full MDS-800s were freakishly expensive, but if I had my choice of any 8080 system, it would be that one. Built like a tank, lots of (multibus) slots, good range of peripherals--a very nice system.
 
I have one of Torode's controller and drives, based on his original
drive.
The controller sits in the drive box with a simple bus interface
in my IMSAI.
There are 2 SA-801's in the box and the label is:
Digital Systems
This was Torode's company in Livermore, Ca.
The bus interface is quite simple and if you know how
to make the bus interface, you could make the MCS 8
into a CPM machine.
The controllers don't show up often but are cool.
If you can allow the I/O card to DMA to the bus,
you can make it boot CP/M without any ROM in the system.
You just hit reset and let the disk load the boot sector.
You then start the code at 0 and it boots CP/M.
Dwight
 
So in the meanwhile I've built an 1702 eprom programmer to read
an preserve all the EPROMs in the machine. I didn't want to use the
machine before I had the EPROMs saved. You never know what
can go wrong with a machine and destroys all information.
(I had an Olivetti P6060 once which had 20V on the 12V line... :crazy: )

So today I've connected it to a modern PC to figure out how to start
the monitor program. There is a label which says 2400 baud but that gave
only rubbish on my screen. I've measured it with my oscilloscope and
the data was at 1200 baud. And the first thing the machine tells you is: 8080 V2.0

In the film I start the system by jamming C3 00 38 @ address 0 to jump to the EPROM @ 3800
after the reset. This is where the debugger is in this machine.


(I'm sorry for my probably Dutch sounding English)

Regards! Roland
 
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Aaaahhh... 30 years I spend looking for one and you pick it up close to home for EUR 50. It hurts. It hurts.

Great to see it in such perfect condition though!

Cheers,

Oscar.
 
Wow, Cool.
Since it has a 8080, it would be possible to make it
run CP/M. You might be a little constrained by available.
It is hard to boot strap a CP/M without 64K of RAM since
the images available on the web require that. It can be done,
though.
Dwight
 
Hello Dwight,

Running CP/M would be very nice! But I wonder if it could run on
the 12KB of memory which is in this machine. (4KB per ram board)
Maybe an early version of CP/M will run under the 16KB?
Otherwise I should add a memory card, which is probably hard to find.

Regards, Roland
 
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Roland Huisman said:
Hello Dwight,

Running CP/M would be very nice! But I wonder if it could run on
the 12KB of memory which is in this machine. (4KB per ram board)
Maybe an early version of CP/M will run under the 16KB?
Otherwise I should add a memory card, which is probably hard to find.

Regards, Roland
Click to expand...

You could always make a memory board. A single CMOS memory chip
would easily give you 64K of memory. You could make a simple memory
decoder with not much effort with 74138 and or 74134s.
Or use a pal or newer part.
Finding a memory card for that machine would be extremely difficult.
Most that are out of the frame would not be recognized and most likely
sent to the scrapper.
Anything in a machine would most likely require purchasing the entire
machine.
Building one on a prototype card would be the best option.
For CP/M you might need to make a shadowing method for any
ROM at the low address range above 100H. CP/M expects RAM
starting there.
It should have a ROM disable line that would be handy. If it has the
same bus as the 8008 machine ( and I believe it does ) you can
shadow the ROM with pin 97 and use pin 93 to enable the RAM
at those addresses.
Dwight
 
Interesting. I also have one of these. I haven't powered it up since I got it many years ago on a flea market south of Stockholm. I think the price was the equivalent of 10 euros. Mine came with an external tranformer to make 110V from 220V. Is your a 220 unit from the beginning?

I am curious, what kind of software can I run on this?
 
Most of these older Intel machines had power supplies with
jumpers to select different voltages.
I'm surprised that someone would add a transformer.
All that normally needed is to change the wires and use
a fuse that is 1/2 the value.
You won't find bargains like that any more. You could buy
a nice used car with one now.
You might check the processor board. These came with
8080 and 8008 processors.
There is not much software available now for these. The
conversion to larger memory makes it practical to play
with CP/M. Mass storage might be an issue but there are
quite a few simple ways to add a IDE 8 bit hard disk or flash
card. Doing a floppy is actually harder.
Although, one can write and assemble code on these machines,
through the serial interface, they were really intended that
you would use a separate system to create the code and
then down load through the serial.
Dwight

Dwight
 
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@ MattisLind,

My unit was already wired to 220V. But as Dwight told already, you can
set the machine on 220V itself. But please note that there are
two transformers in it. You have to set them separately.

@ Dwight,

About the software for the machine. I really wonder what is the use
of the other eproms in the machine. There are 17 eproms in it.
But only a few of them are for the monitor. And almost all eproms are
fully loaded with code. No readable text in the hex viewer, only code...

There is also a hand written document about how tu use a papertape reader on the machine.
You can load papertape images into the ram to program an eprom in the front socket.
Maybe there is more to do with the machine.

I also wonder why there is an 2400 baud label on a board ánd the rs232 connector.
Maybe an other part of the software runs at 2400 baud... But I'm not sure
if you can set the baud rate by software in this machine.

It might be nice to add some memory and some sort of drive in the future indeed.

Regards, Roland
 
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17 eproms is not a lot of code.
Just a little over 4K.
I'd suspect that a monitor with simple
functions would take up 1.5K to 2K.
Add any thing else like a printer driver or
such and you've about used most of it up.
You should run a disassembler on it to see
what it is up to.
Dwight
 
Hello Dwigh,

You are probably right about the eproms.
There are a few holes in the eprom memory map.
I wonder why that is. Nice stuff to figure out in the winter.

btw, If anyone is interested in the eprom files just drop me a line.

Regards, Roland
 
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