[MSX] MSX-Audio BIOS upgrade for Music Module

JP Grobler jpgrobler at krugersdorp.ng.org.za
Mon May 2 06:59:06 CEST 2005


FRS

Thanks for teh reply, no luck yet

> Where did you connected the pin-15 of the 74LS139? It must me connected to
> the pin-20 of the eprom soquet on the MM.
Connected correctly

>Please note that the pin-20 of both 27C256 and the SRAM must not be
>connected to this same pin, but to the pins 12 ans 11 of the 74LS139,
>respectively.
If i connect them  27256 to pin 12 and 61256 tp pin 11 then the sram is
mapped to 0000., 2000 etc
If I connect them 27256 to pin 11 and 61256 to pin 12 then the  sram is on
1000, 3000 etc

> Also check the A13 pin of your 27C257, as it may be connected to the wrong
> place.
A13 to 74LS193 pin 3

>     Maybe its short-circuited somewhere? Are the A12 and A13 lines
> short-circuited? Because they must not be.
Can't see any

> On the msxaudio-BIOS.gif file, the only lines short-circuited are the "Y"
> like ones that have the same color. There are only two of them, labeled
> "/CS Soquete (pin-20)" and "IC3, pin-1".
Fine

Call Audio still does not work.



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