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Varnishing the wood sides of the 4P
Posted: Thu Oct 03, 2013 6:30 am
by nama
So the wooden sides are a little scruffy on my 4P and 4P drive. I wanted to sand these back and get them looking nice, and then I wanted to coat them with something.
But what to I coat then with?
How did they come originally? Were they varnished oiled or what ever?
Do I keep them as per original (what ever that was), or coat them with varnish for future protection?
So many questions!!!!
Thanks
Philip
Re: Varnishing the wood sides of the 4P
Posted: Thu Oct 03, 2013 7:24 am
by MK14HAK
Hi Nama, I read somewhere they were oiled.
By the way is your C4 running cegmon. If so what is at $FF26 =$F6 $F4 or $F7 ?? and does it have 505 or what CPU board ??
Cheers Mike
Re: Varnishing the wood sides of the 4P
Posted: Fri Oct 04, 2013 6:52 am
by nama
Thanks for the info.
But maybe not oiled, but maybe they were stained??? I only say this because where I see scratches the wood is lighter color underneath.
Sorry I don't have cegmon. and my CPU board is 505B.
Phil
Re: Varnishing the wood sides of the 4P
Posted: Fri Oct 04, 2013 9:28 am
by MK14HAK
Phil,
Thanks for the C4 info. I am trying to find out how Cegmon was normally installed with the FC00 page re mapped to either F4 or F7 I think ?
" In 1980 OSI changed both the look of their machines, adopting a beige-and-brown colour scheme and renamed their product line from the "C2-4P" to the "C4P" and "C2-8P" to "C8P": none of their computers carried the "Challenger-II" designation anymore (which, of course, created a great deal of confusion amongst owners). The C1P and C4P models had beige metal cases with oiled walnut wood sides."
... from Mark Csele web site.
Mike
Re: Varnishing the wood sides of the 4P
Posted: Sat Oct 05, 2013 12:07 am
by dave
Hi Mike,
You could re-map it anywhere. However, it was easiest to remap to F400, since it could be done with little circuitry. I did this on my 502-based machine, but I believe the 505 is pretty much the same.
The easiest way is to remove the 502/505 block-remapping circuitry, and just hook the address lines up to the EPROM to address the whole EPROM directly, making sure that the EPROM is enabled when any address in the $FXXX range, except $FCXX is addressed. Since it's a 2K rom mapped into a 4K space, the contents can be seen at $F000 and at $F800. So the $FC00 block can be remapped to $F400 without difficulty (but needs to be re-assembled). I can't remember why the whole ROM wasn't just assembled at $F000 for the C2 machines.
I have a write up of what I did
here. It's in the
Tips, Tricks, and Notes section of osiweb.org's main page.
I will have to re-visit that to see if I over-complicated it at that time.
Best regards,
Dave
Re: Varnishing the wood sides of the 4P
Posted: Sat Oct 05, 2013 1:13 am
by nama
MK14HAK wrote:
The C1P and C4P models had beige metal cases with oiled walnut wood sides.
... from Mark Csele web site.
Mike
Sorry, maybe you are right. I'll look into it some more. Thanks