I always wanted to own a Multitech (nowadays: Acer) Microprofessor

even in the early 80s. I started my journey into computer programming on a similar system, the Busch 2090 Microtronic: 

At the time the Multitech Microprofessor MPF-1B was becoming popular in my hometown Hamburg / Germany, I was about 12 years old. I then got the Microtronic at the age of 13, and it was certainly a better choice for my juvenile brain. However, the Microprofessor just seemed so much more capable and professional. So much I did realize.

Fast forward ~ 34 years later, I started adding a number of Microprofessors to my collection of retro computers. Since 2016, I added:

So by now I have 1 MPF-1B, 2 MPF-1P, 2 printers (they are identical expect for their EPROMS - I have one set up for the MPF-1B, and one for the MPF-1P), BASIC and Forth EPROMs for the 1P, and BASIC for the 1B. I also extended the SRAMs of these machines; i.e., my MPF-1B has 8 KBs of SRAM by now.

Here are a few pictures of my two MFP-IP's; one is set up for Forth, the other one for BASIC: 

This Hackaday project is an ongoing documentation of my exploration into the wonderful world of Microprofessor machines.  By now, I have made a number of videos - stay tuned for future updates!


MPF-1B Part 1: Monitor, Z80 machine code, printer, disassembler.


MPF-1B Part 2: Palo Alto TinyBASIC.


A modern, extended version of the MPF-1B Part 3: "CPU 80" by Prof. Wichit Sirichote.


MPF-IP Part 1


MPF-IP Part 2: BASIC


MPF-IP Part 3: FORTH, Part 1


MPF-IP Part 4: FORTH, Part 2



MPF-IP Part 5: FORTH, Part 3 - THE DARK SIDE OF THE FORTH

Well, still no recursive definitions; too much ground needed to be covered first - but next time!

MPF-IP Part 5: FORTH, Part Forth umm 4 - Recursion in FORTH

Finally, we have everything to define recursive words! This is going to be a little bit longer (over an hour), but you will learn the following: 


MPF-IP Part 6: FORTH, Part 5 - DOER/MAKE

The pinnacle of my Forth exploration - as promised, we are developing a simplified version of the infamous DOER / MAKE constructs from Leo Brodie's "Thinking Forth" book for the Microprofessor, and demonstrate its application by implementing yet another recursive version of the factorial function. Since DOER / MAKE is using the return stack to pass control we are also spending some time discussing flow of control via the return stack, as well as R> and >R. So long, and Goodbye FORTH! We had a fun time together.