Re: Assembler for IIgs

[dempson@actrix.gen.nz (David Empson)]

Allen Bong <sfbong@tm.net.my> wrote:

> I am new to GS and PRODOS.  I have a few questions on them:
> 
> 1. Is there a mini-assembler for 65816 on the GS ROM ?

Yes.  Get into the monitor in the usual way (CALL-151), then type ! at
the monitor prompt.  Press return on a line by itself to return to the
monitor.

You need to be careful when entering immediate-mode instructions - the
number of digits entered is used to determine whether the operand is 8
bits or 16 bits.

e.g.

LDA #3 or LDA #03 will expand to A9 03.
LDA #003 or LDA #0003 will expand to A9 03 00.

The IIgs also lets you enter the first instruction as part of the
command to invoke the mini-assembler (immediately after the !).

> 2. Where can I get a simple 65c02/65816 Assembler before I spend money on
> the expensive macro assemblers.

My recollection is that some versions of the Merlin assembler were made
available as freeware after the death of the author, Glen Bredon.  I'd
like to see reliable confirmation of that before making too many
assumptions, however.  (I bought it from Roger Wagner Publishing many
years ago, so I've never needed to chase up a "free" version.)

In the case of Merlin, you need Merlin-16 or Merlin-16+ to get full
support for the 65816 instruction set.  Merlin-8 has limited support.

> 3. How do I get the date stamp onto my files when I save them in prodos?

As long as you have booted via ProDOS-8 1.2 or later, the IIgs clock
will automatically be used to timestamp files.  Make sure your battery
isn't flat and the date and time have been set correctly in the control
panel.