Code listings for the I4004 or I4040

dwight dkelvey at
Thu Mar 17 14:18:48 CDT 2016

 The 4289 can be used for RAM with the 4040, using the WPM and RPM. It can be used
on the 4004 but it is limited to WPM only.
The RAM can then be use for both program and for data.
I don't recall if the 4008/9 support the RPM but I can look that
up later tonight.
It sounds like you may have a MCS4-02 or -03 board.
I'd love to see a picture of what you do have.
Don't assume the EPROMs are empty. I have a working system
with 3 1702As programmed in 1973. They still contain the original
data and work fine ( I have of course backed up the data ).
There are several assemblers and simulators available on the web.
I use my own home brew assembler and simulator. The assembler
is straight forward but simulators are tricky. If you don't know how
to write code ( usually using the same compiler ) you may not be able
to do much useful simulation. Attaching realtime I/O functions can be
tricky as they are the useful testbench part of the simulator.
You are welcome to my tools but they are written in Forth ( Win32 Forth ).
In any case, please don't erase the EPROMs, thinking they are blank.
I offer my services to read them. Also, there may be someone closer
to you that can extract the data.
It is also, not that hard to create a socket adapter to read out on
a programmer that can read 2716's. It does require an extra
power supply for the -10V.

From: cctalk <cctalk-bounces at> on behalf of Eric Smith <spacewar at>
Sent: Thursday, March 17, 2016 9:19 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Code listings for the I4004 or I4040

On Thu, Mar 17, 2016 at 9:04 AM, Kyle Owen <kylevowen at> wrote:
> Wow, an engineering sample 4040. Very nice. Highly sought after by those
> CPU collectors out there.

I noticed that it was an engineering sample, but hadn't really thought
about that making it more valuable to collectors. Perhaps I should
sell that chip and buy a production 4040 for my homebrew system.

I'd also like to get a 4201 clock generator, 4289 memory interface
(replaces 4008/4009 pair with one chip), 4265 GPIO, and 4269
keyboard/display interface.  And some 4002 RAMs.

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