Re: 'Hello world' for monitor mode and an assembler?

[Alistair J Ross <mail@ataliross.co.uk>]

On Thu, 09 Sep 2004 00:06:32 +0000, Michael J. Mahon wrote:

> Bill Garber corrected:

>>Now 300L will give you: 
>>
>>JSR $FBDD 
>>RTS 
> 
> Of course you are correct.
> 
> Brain alpha particle hit...  ;-)


It's ok - I worked it out all by myself anyway ;)

Two last questions (I hope!) -- how is it possible to know what hex
value refers to each assembler instruction. Ie you knew that $60 gives an
RTS (return from subroutine?). I have the Apple II red book which lists
all the 6502 instructions, so I can at least find out bit by bit what each
one does, but I have no idea how to assemble from hex.

Last thing: Until I get another real Apple II (I'm waiting on a IIe and a
Platinum), i'm using xkegs here on my Linux box. When I do a call-151 then
I type ! to get to the mini-assembler, how can I write line by line
assembler - do I have to know what the next address is and enter it
manually, ie:

300: JSR $FBDD
303: RTS

I had to know that JSR $FBDD was 2 memory instructions long. Or am I being
stupid here, should I just know that JSR $FBDD (because it is seperated by
a space) is 2 memory addresses long.

Kindest Regards,

Alistair Ross

> 
>>"Michael J. Mahon" <mjmahon@aol.com> wrote in message 
>>20040908152808.25764.00000334@mb-m07.aol.com">news:20040908152808.25764.00000334@mb-m07.aol.com...
>>
>>: [ snip ] 
>>
>>: You can enter new data into any location or range of locations by
>>: typing the first address (in hex), followed by a colon, followed by
>>: pairs of hex digits, one pair for each byte to be changed.
>>: 
>>: For example, typing 300:dd fb 20 60 will change the first four bytes
>>: at $300 to DD, FB, 20, 60, as you can verify by typing 300.303 to
>>: list the four bytes.
>>
>>This is not correct Michael. The correct insertion would 
>>be:  300:20 DD FB 60, as this would place the JSR in front 
>>of the low order byte DD and high order byte FB, then RTS. 
>>
>>Now 300L will give you: 
>>
>>JSR $FBDD 
>>RTS 
> 
> Of course you are correct.
> 
> Brain alpha particle hit...  ;-)
> 
> -michael
> 
> Check out parallel computing for 8-bit Apples on my
> Home page:  http://members.aol.com/MJMahon/

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