Ohio Scientific Challenger 4P/MF

From: Bill Sudbrink <wh.sudbrink_at_verizon.net>
Date: Sat Jul 31 15:59:03 2004

I wrote earlier:
> > 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.

Oh! There may be a ground wire attaching the upper metal case to
the lower metal case. Watch for it.

Hope this helps,
Bill Sudbrink
Received on Sat Jul 31 2004 - 15:59:03 BST