created: 2015/07/11
updated: 2016/01/03

Ohio Scientific (OSI)

I the proud owner of an Ohio Scientific Challenger III (C3) vintage computer. This is the computer that NBTel used in the early 1980s to build various "special assemblies" for the New Brunswick telephony network.

I acquired the computer and much of the documentation when the unit was deemed obsolete in the late 1980s (maybe early 1990s).

The C3 was state of the art in the late 1970s with:

Three processor CPU Card; 6502, 6800, Z80
CPU clock switchable from 1Mhz to 2MHz
48k static RAM memory
Dual 8 inch floppys (Shugart SA801 drives)
RS-232 port supporting from 300bps up to 19.2kbps
8-bit parallel I/O port
48 line BUS with 16 slots for expansion
0S-65D fast low overhead development operating system
OS-65U advanced business operating system
Microsoft BASIC

For more information:

Hardware Inventory

The C3 system consists of five boards; CPU card, floppy disk controller, three 12k memory cards and dual 8 inch floppy driver.

C3A Boards
----------
+ 510         CPU Card            (1979)
+ 470 Rev B   Disk Controller
+ 527         16k Memory Card             (x3 48K total)

OSI Boards
----------
+ 505 Rev B   CPU Card            (1979)
+ 502         CPU Card            (1978)
+ 565         Votrax SC-01-A i    (1978) 
+ 550         Serial I/O Card     (1977)
+ 574         Analog I/O Card     (1980)
+ 567         Telephony Card      (1980)
+ 570 Rev C   Real Time Clock     (1980)
+ 580         Backplane           (1978)

Third Party Boards
------------------
+ 8522        Aztec 48k Mem Card  (1981)
+ 106         Serial I/O Card     (vendor unknown)

Disk Drives
----------
+ Floppy      Surgart  Model 801          (x2)
+ Floppy      Siemens FDD 100-8E

Software Inventory

All my software is on 8 inch flopy diskettes. Since my disk drives are acting the fool I am not able to read the diskettes.....yet.

Name                Version         Date        Serial#     Vendor
----------------....------------....----------..-------.....------
OS65D               V3.2            1981/06/05  81-1541     OSI
OS-65U              V1.2 Level 1    1981/07/22  81-1469     OSI
OS-65U              V1.2 Level 1    1981/06/11  81-1144     OSI
Word Processor      WP2             ----/--/--  -------     OSI
OS65D Editor        --              ----/--/--  -------     OSI
EPROM Programmer    --              ----/--/--  -------     OSI
Phone Demo          CA-15           1980/11/04  80-0122     OSI
Demo Disk           --              1981/05/29              OSI
CA-14 Voice         --              1979/03                 OSI
OS65D Vocalizer I   --              ----/--/--  81-0028     OSI

FBasic Compiler     V1.16           1982/03/26  1016        Pegasus Software
Trace               --              ----/--/--  -------     Pegasus Software
FORTH               --              ----/--/--  -------     Software Consultants 

System Exorciser    --              ----/--/--  -------     Unknown (OSI??)
Pretty Printer      --              1982/07/28              Unknown
Adventure Game      --              ----/--/--  -------     Unknown

I am working on creating disk images of these diskettes. As part of that process I have created a OSI Disk Dump utility to help me verify the disk images are formated correctly. It is also useful is exploring the content of the disk images.

I have a couple of the diskette images created .....OSI Floppy Disk Images

Manuals and Documentation

OS65U

OS-65U V1.1 Operators Manual June 1978 (88 pages)
OS-65U V1.4 Reference Manual M/A-COM OSI (~100 pages)
OS-65U V1.43 Reference Manual (Published Manual~200 pages)

Table of Contents

OS65D

OS-65D V3.0 Oct 1978 (66 pages + 11 page User Guide)
Ohio Scientific Disk Basic Reference Manual (15 pages)
65D Tutorial and Reference Manual Aug 1981 (~240 pages)
OS65 Listing Manual (~90 pages)
- bit of a mixture in this manual (and I am not sure V4 was ever released)
- OS65D Version 4 modifications (30 pages)
- OS65D V3.0 assembler listing (53 pages)
- System Memory Maps (2 pages)
- Useful BASIC Pokes (6 pages)
6500 Assembler/Editor Users Manual (~30 pages)
Assembler Editor and Extended Monitor Reference Manual (43 pages)

BASIC

BASIC Reference Manual (ROM. 65D and 65U) (43 pages) OSI-Microsoft BASIC Assembler Source Listing (~115 pages)

Service Manual

Servicing Data for Computer Boards (183 pages; 1-47 missing)

470 (Floppy)
505 Rev A
510 Rev C
520 Rev B
520 Rev C
525
527
535
550
555
590
592
594

part of the manual.... still scanning this one

OSI Misc Manuals

The Challenger C2-8P User Manual Sept 1987 (~100 pages)
Word Processing WP-2 (~47 pages)
Word Processing WP-3 (~75 pages)
CA-22 Analog Input Output Interface Operation Manual May 1980 (~75 pages)
Votrax Voice Output Preliminary Manual Sept 1978 (7 pages)
Serial Interface Operation (6 pages - more like preliminary notes )
PROM Programming Board (Model 450) (~25 pages) pdf
CA-23 EPROM Programmer Manual Jan 1981 (~30 pages) pdf
- includes EPROM Programmer Driver V1.1 Listing

Software Consultants (Memphis TN)

OS-65D V3.2 Disassembly Manual (59 pages) not my copy, but here is a link to a pdf
FORTH manual (7 pages) and appendix fig-FORTH Installation Manual Aug 1980 (53 pages) pdf
print-out of 65U FORTH screens 1-65 (23 pages) pdf

Pegasus Software

FBASIC Compiler V1.0 (20 pages) pdf
FBASIC compiler V1.1 (43 pages) pdf
Trace V1.0 1980 (6 pages) pdf
A/65 Assembler V1.0 1980 (25 pages)pdf
A/65 printout of test routines pdf

MnM Software Technologies Inc

Basic Compiler User Manual (110 pages)

Aztec

8503 CPU Board Schematics (12 pages)

Other Stuff

First Book of OSI by Jim Williams and George Dorner

2016/01/03

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