Ohio Scientific Challenger 4P/MF

From: Bill Sudbrink <wh.sudbrink_at_verizon.net>
Date: Sat Jul 31 15:31:11 2004

> Does anyone have any information or instructions on how to
> connect the 4P to a display? I have the computer but I'm not
> able to connect it to anything. There are 6 what appears to be
> RCA type plugs on the back, 2 wide by 3 tall, with + over one
> column and - over the other. What do I need to do to get this
> thing working?

Standard composite out (color) on the top left RCA jack, provided
that nobody has hacked it. You can connect this to a TV set, just
like you would a VCR. The pot controls the color balance. If all
is well, it will power up to a screen full of garbage characters.
Pressing the "BREAK" key will clear the screen and provide a prompt...
probably "D/H/M?". Pressing "D" (note that "SHIFT LOCK" must be in the
depressed state) will cause it to attempt to boot from the floppy (you
may hear the heads seek). If you get this far, I can make you a couple
of boot diskettes with various demo programs on them. "M" will get
you into an almost useless monitor program that will allow you to
examine and set memory values in hex. I'm currently troubleshooting
a bug in my C4Pmf, so if you get to needing the diskettes too quickly
you might have to wait on me. In all likelihood, at the very least
you will need to open the box up and reseat the cards on the
"fatherboard" as the tinned pins are notorious for oxidizing, resulting
in poor contacts. Just put the machine on its back and remove the
six screws on the bottom... the wooden side panels with the bottom
metal plate should just lift off.

Hope this helps,
Bill Sudbrink
Received on Sat Jul 31 2004 - 15:31:11 BST