Re: [stella] Hardware questions

Subject: Re: [stella] Hardware questions
From: "Bill Heineman" <burger@xxxxxxxxxxxxx>
Date: Thu, 10 Dec 1998 10:24:09 -0700
>What would happen if you had 2 ROM chips selected
>(by design) at the same time on a data bus?
>
You would use a LOT of power.

>Is there risk of damaging any chips on the bus?
>
Yes, not immediately, but over time the heat damage to the chip trying to
drive the bus
high (Logic 1) would shorten the life of the ROM by a lot.

>What data byte would the CPU get if the data from
>chip1 is $00 and chip2 is $FF?
>
You'd get a 0. You see the 5 volts from the FF would be grounded and all the
current
would be drained by the chip giving the logic 0. In most cases this results
in a logical "AND"

Hence  0xFF AND 0x00 will equal 0x00

Burger

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