Re: Paged memory sound boards...

For page flipping, find the page register and change
the page number, then do the signature on each bank,
perhaps?

Tony

--- John Robertson <jrr@flippers.com> wrote:

> Gah, there are days when I wish I fixed simple
> things, like rocket engines...
>
> Currently I'm trying to figure out how to test a
> Williams sound board
> that uses a 6809E with 172K of paged ROM memory
> (address bit toggled)
> that is working only with some lower size ROMs, but
> not with the
> program memory (verified!) for the particular game -
> Riverboat
> Gambler. Bloodly black magic sound boards if you ask
> me!
>
> So, the sound board (D-11578 I think is the number)
> will work with
> Police Force sound ROMs (27256) installed, but not
> with either
> Whirlwind or Riverboat Gambler (27512) ROM
> installed. Jumpers are
> correct, no defective sockets, RAM is good, can
> select the individual
> ROMs with the 6809E pod. However I don't get the
> Reset BONG
> noise...except two separate times:
>
> The first time was when I had placed my Bugtrap
> Logic Comparator on
> the 74LS175 (ROM select logic) - then the sounds
> worked properly!
> However when I replaced the suspect 175, no sounds,
> and when I put
> the original 175 back in the (now socketed) PCB, I
> don't get the
> sounds even with the Bugtrap the same way.
>
> The second time I got a Reset BONG repeatedly when I
> first tried the
> 6809E pod on my 9010 - did RAM tests, BUS tests,
> etc, then tried RUN
> UUT - then shorted the PCB Reset line and BONG! And
> again (Reset)
> BONG (Reset) BONG...sigh, checked original CPU back
> in socket - no
> BONG, put 6809E pod back in - no BONG!!! ARGHHHHH...
>
> Checked BUS - fine, voltages - fine, pullups - all
> fine, socket
> connections to ICs fine....I'm missing SOMETHING!
> Pulled out
> Motorola's data book in the off chance that Williams
> engineers missed
> something special about pullups on unused lines -
> nothing so
> far...(this was the case on Game Plan MPUs about the
> Z80! nasty bit
> of bad design there.)
>
> I think this board is going to become a frisbee!
>
> John :-#(#
>
> PS, remind me to fix the description line on the
> email reply...
>
> --
> John's Jukes Ltd. 2343 Main St., Vancouver, BC,
> Canada V5T 3C9
> Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes,
> VideoGames)
> www.flippers.com
> "Old pinballers never die, they just flip out"
> _______________________________________________
> Techtoolslist mailing list
> Techtoolslist@flippers.com
>
http://seven.pairlist.net/mailman/listinfo/techtoolslist
>

                
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Received on Tue Feb 22 23:31:41 2005