Sorry if this is a simple question, but I was wondering after looking
at the Ram usage: why does the 8049 access the ram with an address
latch connecting to A1-A8 where as it's an A0-A9 device? Is it still
using all 10 addresses or only 8?
Thanks in advance!
--- In PolySix@yahoogroups.com, "cavernosum7" <klosmon@...> wrote:
>
> Michael Grossman wrote:
> >Cavernosum, I bought a broken polysix which plays in tune and sounds
> >great except the programmer is flakey. Upon probing IC22-13 (DB1) I
> >noticed the pin has very low amplitude (<2V). I thought perhaps the
> RAM >chip might be bad so I pulled IC22-13 out of the socket and
> confirmed >the amplitude is still low. I am now convinced the
> uPD8048-245 is bad.
>
> Not necessarily. Have you checked IC31? On units with battery
> leakage, this is one of the most commonly damaged ICs. Try replacing
> that; if it still doesn't work, I'll sell you a new CPU.
>
> >I would also like to buy a replacement 1kx4 static ram (TC5514APL-3)
> if >available.
>
> Good news: you can use a 6514 RAM chip and it works exactly the same.
> These can be ordered from Jameco Electronics for about $4 each;
> Jameco part number 43238.
>
> ~GMM
>