In the 70's, personal computers were a fresh idea. Your
choice of computer was as much an individual expression as your
choice of car. One of the earliest makers of complete computer
systems was a small company called Ohio Scientific. They
specialized in bare boards and kits for hobbyists, later focusing on
fully built, integrated systems. I bought my C2-4P used in
1979, after hanging out at computer stores and drooling over PET,
Apple, and the C2-4P for a couple of years. The Challengers
were perhaps the most conducive to hacking because of their spacious
layout, modular design, and simple bus structure. There are
other sites that recount the history of these machines and the
company that made them (see the links section.) Recently, I dug
out my old C2, removed lots of blue wires, restored many traces (I
would like to add a hacks page later) and got my machine back to the
familiar C/W/M? prompt.
This archive is a repository for OSI
literature and software. I've attempted to arrange it in as
sane a fashion as possible.
I welcome contributions,
especially of software and scanned (or paper) manuals, stories, tips,
tricks, hacks, and other info. I am also interested in working
and non-working OSI hardware, either photos or the real thing.
I'd
love to hear from any other OSI'ers. Please check out theForums
section of the archive, and post any comments, corrections, or
memories for all of us to enjoy! You can also email me privately via
the Forums section.
With no further ado, here's the
archive:
Hardware
Software
Journals
Manuals
Books
Tips,
Tricks, Notes
Links
OSI
Forums
|
Board |
Description |
|
470 |
Disk controller card. The interface contained a 6820 PIA for control lines, and a 6850 ACIA to read and write data to the disk. The board requires separated data/clock signals, provided by several 8" drives, but very few 5.25" drives. The MPI B-51 drive was the standard OSI mini-floppy, and held 40 tracks with 2k per track. There were many articles in PEEK(65) on how to improve the disk interface, build data separators, etc. Some of these are in the scan section. Apparently, the PIA could be populated alone, for use as a parallel I/O card. |
|
502 |
6502-based CPU with on-board 8K BASIC-in-ROM, 2K ROM monitor (with a complex addressing scheme to allow physical remapping of 256-byte ROM pages), 8K RAM, 6850-based serial port with audio cassete or RS-232 interface. |
|
505 |
Like the 502, but for disk-based systems. Omits the BASIC-in-ROM and the KCS cassette interface, but adds a 470-equivalent floppy interface. |
|
540A |
Second-generation video board with 64x32 characters and guard bands (First generation was the 440, with 32x32 characters and no guard bands, similar to the circuit in the Superboard/Challenger I). We loved this card because it was so hackable. |
|
540 rev B (pic) |
Design similar to the 540A, but adds 4-bits of color. |
|
542 rev B |
Keyboard to accompany the 540B. |
|
527 |
24K RAM board. With forty-eight 2114 chips, this board required it's own power supply, separate from the main supply. |
|
Hard Disc controller board. | |
|
600 |
Sold as the "superboard", or with a case and power supply as the Challenger I. This was a single board system incorporating a built-in keyboard, 8K BASIC-in-ROM, 2K ROM monitor (without the complex remapping scheme), 8K 2114 RAM, 32x32 char video with 1K 2114 RAM (similar to the 440 card), and a serial port with audio cassette or RS-232 capabilities. Hook up a power supply and monitor, and this is a complete computer system, like an Apple II, but for $279. |
|
Like the original, but with an extra 1k x 4-bit video RAM for color | |
|
Like the rev C. |
|
A beginner's tutorial on 6502 machine-language programming, featuring the (primitive by any standard) OS-65V monitor program. | |
|
The C4P User's manual. Shipped with C4P systems. | |
| C1P Manual | The C1P User's Manual - (thanks to Mark) |
|
Looks like a scan of an older version; longer, but with plainer typesetting. Much of the contents appear similar. | |
|
The reference card included with my shiny new OS65D binder when I got my disk upgrade. | |
|
A scan of a bootleg version of the (I believe) Aardvark notes on ROM Basic. If you have a better version, let me know! | |
|
| |
|
A very thoroughly annotated disassembly of OS-65D. Every little trick, bug, secret, and wart is exposed. If you're looking into any OS-65D mods, development, or disk interfacing, this is your resource. | |
|
This is the manual for the Microsoft 8K ROM Basic (rev 3.2) that shipped with the C1/2/4/8 machines. | |
|
Coming soon: Sams C1P repair Manual |
|
|
This is the SAMS repair manual for C2/C4, including 502, 505, 527, 540, and 542 Boards. Full color. Large file! | |
|
|
|
| Micro on the OSI | Compilation of Micro articles for OSI |
|
A list of known OSI boards. If you have additions, let me know! | |
|
Notes on replacing 4116 triple-supply chips with 4164 5V-supply chips, which are also cheaper and easier to find. Lifted from the video-game repair community archives. | |
|
Notes on the Disk driver routines for OSI Disk BASIC | |
|
A few notes on various OSI Roms, by Mark Spankus. | |
|
Notes on modern replacements for hard-to-find OSI components | |
|
How to modify a 502 board (and CEGMON ROM) to use the CEGMON monitor with minimal surgery. |
|
|
|
|
An excellent pan-OSI emulator for Windows, WinOSI, by Mark Spankus. Mark also has plenty of other goodies, many of which are on this site. | |
|
BASIC Garbage collector bugfix; several very useful utilities including audio tape decoding tools. | |
|
A General OSI reminiscence page with lots of interesting info and pictures | |
|
Win OSI Page |
(Dead link removed. Email me if you have info.) Superboard II site. Home of a Windows OSI emulator. History of OSI, other info. |
|
A comprehensive site dedicated to the Compukit 101, with plenty of scanned articles, manuals, software, and an emulator. | |
|
Another nice compukit 101 site, with pictures. | |
|
A C1P site with a C1P emulator for windows | |
|
Info and photos of the C4P and C1P | |
|
|
|
|
A resource for 6502 programmers. Useful resources include a code library, forums, and hardware designs. | |
|
A free, maintainted, mature C compiler, assembler, linker, and utilities for the 6502. No OSI port yet. | |
|
A very powerful binary file manipulation utility. It reads and writes numerous binary formats, including OS65V, and can write BASIC DATA and assembler .db statements. |