Re: Are different memory banks special?

[Tristan Mumford <xtristan.xmumford@xgmail.xcom>]

David Wilson wrote:

> On Feb 26, 12:06 pm, Tristan Mumford <xtristan.xmumf...@xgmail.xcom>
> wrote:
>> What I want to know is whether there is anything special about the 3
>> different banks of RAM in an apple ][?
> 
> Yes (if you use standard memory select blocks or have a later board
> that omits the 4K/16K option). Row C is memory locations 0000-3FFF
> with 16K chips which covers pages 00 (zero page), 01 (stack), 04-07
> (Text Page 1). If these chips do not all work the system is useless.

Thankyou.

> 
>> One other question. I'm asking because I'm doubting myself. Looking at an
>> apple][ board, 6502 and slots up back, CHARGEN etc up front, which is the
>> lsb column of RAM. The left or the right?
> 
> Left.
> According to the circuit diagram in the Red Book, C3/D3/E3 are data
> bit 0 and C10/D10/E10 are data bit 7 with the data bits running 0 1 2
> 3 4 5 6 7 across the board from left to right.

Thankyou again. Unfortunately the scan of the reference manual (white one)
that I have is a little too lowres for me to make out what was happening. I
found the page that had the RAM but I couldn't see what the text was.

I guess if it were to work it would need to be like a RAM expansion card. Ie
in one of the slots, and a dip plug in one of the bank chip sockets, or
something like that. 

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