Dusting off the Memories

[Getagrip]

Hello all

I have been dragging my OSI systems around for 40 years and I figure it is time to dust them off and get them running.

I learned BASIC programming on an OSI Challenger 3 in high school, then got a few jobs developing software on OSI along with being a repair technician.

I have a Superboard II that seems to have no clock signal. I am in the process of fixing that and then seeing what else needs help.

My OSI C28P is going to be a longer term project. I believe I have the CPU board running with Basic in ROM, 8k Ram, ACIA, and SYNMON rom. I put a FT232RL FTDI Mini USB to TTL Serial Converter Adapter on the serial lines to transfer files at 300 baud. I fixed a broken diode on the keyboard and did a lot of swapping of 8t26 buffer chips to get everything functional. The 542 video card is currently flaking out after warming up, so I am trying to troubleshoot the final video combiner circuitry.

At one point I did a full disassembly and documentation of the OS65D basic and OS along with some of the monitor ROMs and the OS65U disk drivers. I have a dual 8 inch drive setup that needs some TLC along with a box of 20 or so floppies. I also have a "473" IBM/OSI floppy controller that I am going to try to get functional.

I am happy to discuss any of the features of the OSI cards or OSI software.

[bxdanny]

Hello Getagrip, and welcome.

Your experiences with OSI seem to have been similar to mine. I also had both a C1P and a C2-8P, which like yours was based on a 502 board but converted for floppy operation. And I also worked as a combination programmer and technician for a couple of OSI dealerships.

Unfortunately, I got rid of my OSI systems in 1993 when I moved to a new apartment, so I have to content myself with the virtual, emulated version (WinOSI) and discussions on this board.

Good luck with getting your stuff working, and I'd certainly be interested in any of that documentation/disassembly you may still have and may want to share, and any info about that 473 IBM/OSI floppy board. Is that the one that was sold by D & N?

[Getagrip]

Hi Danny

The 473 IBM/OSI board was a project that I was involved with at Community Computers in Arlington Virginia. There were probably about 10 of the boards made right about the same time that MA/COM was killing the OSI line. I was able to program OS65D to do IBM format double side/double density - but only with a 2 mhz cpu. (Polled 765 floppy controller) The documentation for the 765/8272 floppy chip had a few clues as to how to set up a non-dma polled interface.

Mike (GetAGrip)