[Coco] Transplanting 512K RAM expansion?

[Fedor Steeman]

I could still not find it, so I consulted a CoCo3 schematic I found on the
web. Apparantly, C65 and C66 are associated with the GIME. After some
looking around I finally found them both underneath the keyboard, diagonally
below IC10 and IC6 (GIME)! I guess I must have a pretty weird CoCo3-board.

But thanks for your kind assistance and the test program...

Cheers,

Fedor

On 25/05/06, Stephen Castello <zootzoot at cfl.rr.com> wrote:
>
> On Thu, 25 May 2006 18:14:26 +0200, Fedor Steeman
> <petrander at gmail.com> had a flock of green cheek conures squawk out:
>
> >Two small questions before I proceed:
> >
> >1. How can I, from BASIC, check whether the RAM has been properly
> installed.
> >I know PRINT MEM doesn't work, so aren't there some POKEs and PEEKs that
> I
> >can use?
> >
> >2. Where on the circuit board can I find C65? There is almost a hundred
> >capacitators there, and they are not placed in orderly manner according
> to
> >number.
> >
> >Thanks in advance,
> >
> >Fedor Steeman
>
> NTSC: C65 is next to IC17.
> PAL: to right of CN4, which is next to IC17.  CN4 is one of the
> connectors the 512k board plugs into.
>
> Test program from the service manual:
> (it doesn't test every location)
>
> 10 WIDTH 40:PALETTE 0,0:PALETTE 7,63: CLS8
> 20 POKE&HFFD9,0
> 30 FOR A=&H00000 TO &H5FFFF STEP 512
> 40 D=RND(255)
> 50 LPOKE A,D
> 60 B=LPEEK(A)
> 70 LOCATE 10,2: PRINT"ADDRESS=";A
> 80 LOCATE 10,4: PRINT"DATA=";D
> 90 IF B<>D THEN 130
> 100 NEXT A
> 110 LOCATE 10,10: PRINT"RAM TEST IS GOOD!"
> 120 POKE&HFFD8,0: END
> 130 LOCATE 10,6: PRINT"ERROR!"
> 140 POKE&HFFD8,0:END
>
> Stephen
> --
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco
>