This area contains information related to the Denver Board Model DB-1 for the Ohio Scientific (OSI) Challenger Systems. This was a board designed for their time-share / multi-processing systems with hard drives. The board has its own 6502 processor, 64K of RAM, ROM, and a serial I/O port.
I worked for the local reseller in Tulsa (Computer Synergy by Gaugher & Associates) when I started to college in 1981 and worked there about a year before I struck out on my own as McClanahan Computer Services (later Shamrock Services). I did custom software as well as hardware repair and upgrades.
Using a Challenger System with a 74 Megabyte hard drive, I did a number of benchmarks against other multiuser systems that were commonly available for a client. The OSI with DB-1s consistently outperformed anything else in its price class that I came across. I installed DB-1s for three clients: a construction company who was my main client (who had payroll, general ledger, etc. on the system) and two other clients that called me now and then (a large ministry that primarily handled a newsletter and mailing list with their system and a consumer product manufacturing company where the engineers had developed a fair amount of custom software they used for design work).
I graduated with my electrical engineering degree in December 1985, took a pay cut to work as an engineer (but I could also see the writing on the wall that the days of the "computer consultant" were numbered because the IBM PC was bringing a lot of software that was easier for companies to tailor and use), and tapered off with the work I was doing on the OSIs.
I have seen some people ask about the DB-1 from time to time and knew I had a copy of the manual somewhere. I've finally started scanning that. I believe I have a "spare" DB-1 card that I bought to support the clients I had installed them for, but I haven't found that yet.
This equipment is from the mid-1980s era of vintage computing. There has been a resurgence of interest in restoring older systems or even, in some cases, reverse engineering them to build "clones" or get older hardware running.
The information here is intended for personal use only. It is made available for personal reseach and educational purposes. I believe it to be fair use as defined by copyright laws, but any material will be removed at the request of the copyright holder or those holding other rights to it.