System/3 model 10 emulator was written by Charles 'Dutch' Owen for SIMH
with some assistance from me.
Quoting Dutch: "...we were working on the sim (me writing, he testing
and telling me where I screwed up)."
This emulator has support for:
- IBM 5410 CPU and 64 kbyte storage.
- IBM 5741 Printer Keyboard.
- IBM 5444 Disk
- IBM 1442 card reader (80 column)
- IBM 1403 line printer support.
I added support for:
- IBM 5424 MFCU (96 column)
- IBM 3411 Tape Unit
- IBM 3741 Diskette Station (under construction !)
solved some minor bugs.
download this new release (Feb 2013). The SCP disk image (and
user guide) can be downloaded here
A complete installation log can be seen here
An aws tape with several 'add-on' programs can be downloaded here
this version is written to run with the SIMH version
included in the tar file.
Tip: when running the emulator you really
need this IBM
S/3 HALT guide
and this OCL reference
In 2005 I started to write a model 15B emulator (with 3340 disk
used Dutch's source code as starting point.
My plan was to write a model 15A with 5444 drives, but I didn't had
a 5444 based model 15 System Control Program.
I did have a 3340 version of the SCP, so I started with
The 3277-1 operator console emulation is not perfect and needs
a specialist who is familiar with COLOR ANSI on Linux.
Here are some screen shots:
With a running model 15B emulator (with 3340 drives) I was able to
re-create an 5444 version of the SCP. Unfortunately
all the 5444 specific software modules where missing
(IOS driver: de12
5444 initializer: init2
, 5444 IPL
Luckily I have the source code of all these modules on microfiche, so
after typing in
2000+ lines of
assembler source code,
assembling and linking it all, I was able to re-create these modules.
As already said the weak point of the model 15 emulator is the ANSI
emulation. It is not possible to connect the well
known tn3270 to the emulator. The SCP does not generate 3270
BSC data stream to communicate with the
The screen data is transfered directly from storage via an internal
channel to the adapter and then via coax to the 3277-1.
Then I got the idea to develop an async to IBM coax converter
and connect a real IBM 3277-1 to the emulator.
/===> Real IBM 3277-1
There are some pictures of the result:
Pic 1: the left PCB is an Atmel ATNGW100
running Linux and the
System/3 emulator. The right PCB is the async to coax
Pic 2: The converter is build with an ATMEL Atmega processor and 11
bit serial & deserial logic in an ALTERA
Here are some screen shots of the result:
YouTube demo movie.
The response is quite good and no difference with a real system.
(except less power consumption, space and noise :-)
Detailed specification of the IBM-ANR protocol can be found here
Currently I am working on a connection between a real System/3 operator
panel and the emulator.
The hardware is finished and the software (modified SIMH S/3 emulator)
Here are some pictures. The black box behind the
panel is an 19" Industrial PC, the first type IBM made.
Two PCB's (as shown in the last picture) are needed
to interface between the panel and the PC.
The interaction between the operator and the panel is besides error
conditions and single machine / clock cycles operations identical with
the reel panel.
was needed to make the panel lights flicker as on the original panel.
where I demonstrate this emulator.
A modified IBM Composer Selectric connected via a RS232 connection is
used to emulate the IBM 5471.
Currently I have CCP running on this system. Dutch Owen is now
working on a
TN3270 connection with CCP
running in the model 15 emulator.
See also my 5496 project.
Greg Engelstad has written a complete IBM System/3 emulator in C#.
Please download the source from github