Goal and Hardware for RetroChallenge 2019/03.

During the RetroChallenge 2019/03 my goal is to build and program a system to control outputs and read inputs from a transputer system.

For this purpose i buy a couple IMSC011 Link adapters. These link adapters as speciale made for connecting to an Transputer Link for connecting handware. This could be a interface to an computersystem, like an IBM or SUN or VME system for loading software, or to other hardware to control all different thing’s.

In an former RetroChallenge I build an inferface to an ISA-slot for connecting an Transputer to an PC for loading software, and now I want use this same Link adapter in an other modus to connect some LED’s and switches to control and measering.


The datasheet for the IMS C011 could be found on several places on the internet so this is the startpoint of our Challenge. Reading and understanding the datasheets. This Link Adapter could be used in 2 differend modus. The second modus as an businterface, to connect an ISA-bus for example. The first modus is a Peripheral interface modus. Then you have 8 output’s and 8 input’s and fully handshake control. And this is the modus we go to use.

After building a nice little print a have the hardware to start with my project.


RetroChallenge 2019/03

Next month the RetroChallenge 2019/03 start’s,   http://www.retrochallenge.org/    I wil be a partner of this Challenge. My goal is to controll input’s and output’s with a IMSC011 interface chip for the Transputer. A couple year’s ago I buy some of them and now i want to use them to controll some LED’s and read some switches by the language OCCAM from a real transputer.

Happy RetroChallenge 2019/03IMSC011

Adresdecoding the CSA Transputer interface.

I have get a question about the picture of the interface I have build.


In my interface I have hardwired the adres 150 Hex for the Interface and 160 Hex for the System Signals. The question about the schema for the IMSC011 in place of the IMSC012. I have just take the datasheet’s for the both part’s and connect the right signal to the right place. So there is no different schema for the IMSC011

May the tForth be with you.


At an computer meeting of the Compusers group of the HCC (Hobby Computter Club) I meet Albert van der Horts who is a member of the Dutch Forth Usergroup. This Forth Intrested Group have made a version of Forth for the Transputer, called tForth, around the year 1991 – 1995. Albert have done a lot of work on Transputers. On his website: http://home.hccnet.nl/a.w.m.van.der.horst/transputer.html there is a zip-file with al the information, program’s and code to go work with Forth on a Transputer system. I have download the whole stuff and install it on my system with my selfbuild ISA-Transputer interface.

I am not familiar with Forth. It’s not only a computer language but also an development system. And even more then this, it is a whole different way of thinking of working with computers. In fact you maken your one command’s/statemants build from other existing command’s.

I have no experience with Forth but it looks me a nice challenge to try to start tForth on the transputer with my selfbuild interface. I talk to Albert van der Horst and he explain me the way to start the system. So I do, I start the system and now I can program in tForth. This is also working !!

tForthI think it is a long time ago there was a transputer with a running tForth program on it, but the knowledge is stil availble at the Dutch Forth Interest Group’s of the HCC. ( https://forth.hcc.nl/ )  Always nice to visit a regional computer club.

How I become intrested in Transputers.

A couple years ago I visit a meeting of the Hobby Computer Club te Hooglanderveen te Holland (The Netherland’s). This was the Artificiel intelligence user group. An person have a question about a system. He want to work with Transputers. He has a ISA-I/O cart for a PC. This cart was a bridge between a program under DOS to a serial link to a Transputer System. He has problem’s to get his ISA-cart working.

I know that I have at home some “old” PC’s with a ISA-slot in it. That PC’s are running under W98 and DOS. So I told this to hime and we talk together about his problem. He want to run some program’s on a PC, connectes by the ISA-interface to his Transputer board’s.

I took his CSA ISA-interface and a copy of the installation book at home and a couple week’s later I have install the ISA-interface include the necessary software. This was the first time a come across a Transputer system.


A Transputer is a vintage computer system build arount 1985 to 1995, invented by INMOS, an company from Bristol, UK. The Transputer has 4 I/O links for communication between Transputers so you can build big Transputer processor networks to distrubuted your program so your problem can be solved by many processors. So you can split your task in smal part’s. Together with the Transputer hardware INMOS construct the language OCCAM, special for parallel programming.

Around that time this hole system was a big invention and was to call: the poor man’s CRAY. A lot of computerpower for a reasonable prise.


Picture from website: http://www.conapp.org


RC2017/10, Work with Transputers.

Last month’s was a very busy time. I have a lot of job’s to do at home, for work and church.  Also I have made some time for my new project. Make myself familiar with Transputers.

This is also the goal for this month: “Work with Transputers, try to understand how the system is working.”

I have build a ISA to Transputer-link interface. Let’s go to start to work with it.