Tuesday, February 5, 2019

6809 FLEX™ Adaptation Guide

http://www.flexusergroup.com/flexusergroup/pdfs/6809fadg.pdf

Yes, it would have been running under the Flex9 software. This operating system would have been adapted to my system. Attached to this is a copy of the Flex Adaptation Guide. If you look through it you can see that I had to write the interface routines for the terminal input and output, and the drivers to run the floppy disc system.
Yes, running on the home built 6809 system.
To recap history...

Started with a single board 6800 computer bought as a test unit. Was helping as a TA in electronics at a high school at the time. A senior in the class and I figured out to use it, connected to a teletype at the time.
This lead to building our own boards with more memory, interfacing to an old line printer we found, and finally building a video display board so we could use a TV monitor and keyboard. Everything was stored on punch tape from the teletype which could both read the tape and punch it. Even a primitive BASIC language program was loaded and used. It only needed 4K of memory.
Over the next 2 years I made my own 6809 system. More memory, better video card, floppy disc controller board, audio cassette modem and controller, EEPROM programmer. Wrote all the software to run all the low level interfaces and then adapted the Flex operating system, disc management system, and assembler program to run on it.
Obviously the hard part was to write the first interface routines by hand assembly of the processor instructions in hexadecimal without an assembler.
Eventually build a 300 and 1200 baud modem to access the beginning of the internet over the dial up phone lines. At that time the Internet was called the Arpanet and was run by ARPA, the forerunner to DARPA. The student from high school that I still was in contact with had access to it. There were only 7 universities and some military bases connected at that time. We used to play Zork on the MIT computer by using text commands. But I digress…

1975 Build a Motorola 6800 Microcomputer MEK6800 w/ Schematics Altair 680 SWTPC

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