RetroChallenge 2019/10 –> 2020/04

I have send my Participation of the RC2019/10 to the judge, Michel. My subject is to program and load the Z80 MicroProfessor-1B from a W10 computer/laptop.

The MicroProfessor-1B is a Single Board Computer with a Z80 processor, a hexidecimal keypad and a 6*7segments display. In the 80’s – 90’s It was a great learning system to understand the working of microprocessors and programming. The program you type in on the keypad. The program’s you could store on a casette tape and also restore from an casette tape. Later there where Z80 assembylers so you can type your program on a PC and then send to the MPF-1B. These assembylers works under DOS and send the binaire file by the COM-/printerpoort to the MPF-1B. Nowday these programs are not working and the most computers have no COM-/printerpoort so when we whant to program our MPF-1b we need an other solution.

Let’s program and load our MPF-1B Z80 by a W10 computer/laptop is my goal for the RC2019/10.

The RetroChallenge 2019/10 is moved to next spring. So the next RetroChallenge is in 2020/04.


Conclusion RC2019/03

The last couple weeks I have spend a lot of time to study datasheet’s, programming OCCAM, debugging with a logic analyser en use my soldering Iron to fix some hardware issues. But most of the time i have FUN !!


I can read the INPUTs and write to the OUTPUTs of the IMS C011, the Transputer IO-Link interface.

A small step for humanity, but a big step for me 🙂

I have reached my goal for the RetroChallenge 2019/03

This is very nice because the last part of the month I am not at home. So for my this is the end of RetroChallenge 2019/03.

–END of RC2019/03–


Reading INPUT’s from the IMS C011

After controlling the output of the IMS C011 Transputer IO-Link interface it is now time to take a look at the input’s. Before my friend can build a Robot based on a Transputer system we must can control output’s but also read input’s from sensor’s. So let’s take a look at the Input’s of the IMS C011 Transputer IO-Link interface.

I wrote a little program how i think how it must be work’s.


But nothing happens (ofcourse ?) At saturday 16 March there was an meeting of the HCC!Retro computer club. This means Hobby Computer Club, section Retro computers. This meeting was held in Bilthoven the Netherlands.  HCC!Retro website


During this day we have a lot of talk about Vintage computer systems, core memory, Bubble Memory and other old hobbycomputer stuff. Also we have a little look at the transputer I carryed with me. When I ran the program noting happen, but when a friend of mine take a look at the IO-Interface print I have build he take a look at the backside of the print. On that moment a saw some numbers comming on the screen ??!!


Wait !! What is happening here, then I remember the handshake signal’s. The Ivalid was not connected and this is high impedance so when you are moving your hand in the area “sometime’s” you get a high strobe on the input and then you get a value in your system.

I took a nice little wire and use this as a strobe signal to the +5Volt. When i touch the Ivalid then the value of the dipswitch would be displayed on the screen. Victorie !!!


Next step is to make the system a little bit more better working. I decide to connect the OVaild to the IValid so when i get data for the output, then also the value from the dipswitches goed into the IMS C011 to the Transputer.

Now I read the values of the dipswitch very good.


Lessons I have learned about this: There are 4 handshake line’s on the IMS C011. Think about them carefull !


Software for controlling the IO-Link Interface.

When you made a program in OCCAM you work with channels. These channels could be software in a Transputer chip OR hardware to an other Transputer chip. But how you tell the “OCCAM program” that he must connect / send the informatio to a fixed IO-Link at the Transputer. I could not a good feeling about this situation. After reading a lot of artikels I don’t understand.

During building the IO-Link interface around the IMS C011 i get an book in my hands from Ian Graham and Tim King with the name [The Transputer Handbook] I “walk through” and suddenly i read a nice chapter about the command PLACE .. AT ..

This little tekst open my eyes and slowly i understand how to send a value by a specifyed channel to an IO-Link with an inferface connected. So i write my first little program to send a value to my LED-print. Ofcourse this was not good an i get the wrong value on the LED-bord, but WHY ??


So i start debugging. I found that the Link-speed between the Transputer and the IMS C011 Link Interface was different. The Transputer runs on a Linkspeed of 20 Mbit but the IMS C011 was configurated at 10 Mbit. After using my soldering Iron to correct these mistake i do the test again. But now i see even not lit up a LED ?? What’s wrong now ?? Let’s read the datasheet of the IMS C011 again. There is written that there must be a QAck before ther comes an Ack to the Link back to the transputer. After connecting the QValid to the QAck still no burning LED’s ??


After hookup an logic analyser i get very nice information, see line 1. There comes more then 1 pulse each time i send a byte. Slowly i understand, i don’t send a byte, I send an Integer, that are 4 byte’s !! And the last byte is displaid on the LED’s. So after shifting to left by 24 bit’s I get a wanted value on the LED’s.

Now I am also able to run the KITT-light. See the YouTube link below.

KITT light on Transputer

What’s Next, the output is ready, so let’s start to take a look at the input !!





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,    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