From Wikipedia, the free encyclopedia Ohio Scientific
Ohio Scientific
products were also 6502-based, the Superboard II, Chal-
lenger 1P, Challenger 2P, Challenger 4P and Challenger
8P, introduced in 1979 and discontinued in 1981.
Original Ohio Scientific motherboard designs used
7400-series transistor-transistor logic TTL chips. Instead
of using a floppy disk controller IC, they used the Mo-
torola 6850 ACIA serial-port UART chip, which made
their 8 and 5 inch floppies unreadable on any other sys-
tem.
The company supplied full schematics of their hard-
ware,which allowed for some field modifications, such as
increased clock speed and increased video line length.
Ohio Scientific Challenger 2P, with optional double disk unit. The video systems did not have color-graphics like
On display at the Musée Bolo, EPFL, Lausanne. the Apple II, just upper-case text, and some pseudo
graphical characters, (comparable to the "PETSCII"
Ohio Scientific Inc. (also known as Ohio Scientific In- character-set of the Commodore PET) for drawing lines
struments was a United States computer company that
struments) and supporting simple games. They hadn’t figured out
built and marketed computers from the late 1970s to the how to write to the video memory without glitching the
early 1980s. The company was founded by Mike and display, so the hardware would blank the screen for a
Charity Cheiky in 1975 in Hiram, Ohio.[1] few microseconds while it accessed the video memory.
There was an add-on graphics card for the Superboard
that would display 256 by 256 pixels. It came with soft-
Products ware to draw 3D graphics.
The version OSI C1P / 600D Superboard II (occasion-
ally advertised as the ’Colorboard’) featured an unpop-
ulated socket for an extra 1k x 4-bits of video ram to
hold character colour information. The implementation
of this was detailed in the OSI user group newsletter
which was published around four times a year. The 600D
also featured two video modes: 32x32 (~24x24 visible) for
’graphics’, or 64 x 16 (~48x15 visible) for text where each
text line had a blank line between it and the next. The
mode could be selected by a poke to the keyboard reg-
ister. The keyboard polling register (a simple 8-bit TTL
Latch) was also used as a very crude digital to analogue
converter by means of a resistor ladder connected to an
’audio out’ socket to the right of the keyboard.
The original superboard shipped with an 4KB O.S. in
ROM, known as SYNMON, as the rom was labelled
’SYN600’, and a rather buggy version of Microsoft 8K ba-
sic. Mainly due to the popularity of the superboard clone
Ohio Scientific Challenger 4P ’UK-101’ in the UK, the bugs in the BASIC roms were
eventually fixed, and at least two third-party companies
One of their first products, launched in 1978 was the OSI produced their own version of the OS. One version was
Model 500 system, a very simple single board computer called ’CEGMON’, the other was ’WEMON’ produced by
based on the MOS Technology 6502 microprocessor, but Watford Electronics in the UK. Both featured full screen
lacking a Video Display Controller. It needed an external editing (almost identical to the commodore PET), Named
video terminal such as the VT100, or the CT-64 terminal cassette file handling (like the PET) and a greatly Im-
system from SWTPC, to create a useful system. Their later proved machine code monitor (also very similar to the
Commodore PET).
1
From Wikipedia, the free encyclopedia Ohio Scientific
Software was also minimal: a cassette boot loader in May 1982 OSI name is changed to M/A-Com Office
ROM and Microsoft BASIC in ROM. Disk-based systems in- Systems Inc.
cluded a bare-bones "Disk Operating System", which did
not have file names, only disk track numbers. Users were
advised to reserve track 40 as a text area for a manual
See also
disk directory. Even so, the disk was much handier than The Compukit UK101 is virtually a clone of the Ohio Sci-
reading and writing cassettes at 1200 baud. entific superboard
The OSI Challenger III had three processors: a 6502, a
6800, and a Z80. These were software switchable, but only
one would be running at a time. Because it had a Z80, the
References
Challenger III could run CP/M, but it booted up in 6502 [1] Allan, Roy A (2001). "Transition to
mode, and the bootstrap would switch processors. Microcomputers". A History of the Personal Computer.
The operating systems which ran on the CIII were OSI Allan Publishing. ISBN 0968910807.
CP/M, OS-65D, and OS-65U. All three OS’s, at least in the http://www.retrocomputing.net/info/allan/
later versions, had directories with file names. eBook04.pdf.
OSI/CPM had an assembler, FORTRAN and COBOL
compiler, but to make a copy of the CPM, one had to External links
boot in OS-65D to copy the disk. OS-65D had a Basic in-
terpreter, Assembler, Editor, disassembler, and disk copy • Marcus Bennett’s OScientific Documentation Store
utility. OS-65U had a Basic interpreter, and had some • Dave’s OSI repository.
simple networking capability, but assembly programs • Dave’s OSI forum.
had to be done in OS-65D and then ported over. • Mark’s OSI and Compukit archive
• Srecord program: multiplatform hex reader writer
understands OS-65V hex dumps
History
Mar 1981 OSI is sold to M/A-Com Inc. of Burlington MA.
OSI will concentrate on business systems.
Retrieved from "http://en.wikipedia.org/w/index.php?title=Ohio_Scientific&oldid=462119702"
Categories:
• Early microcomputers
• Companies established in 1975
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