Subject: Re: [stella] DASM wish list From: xucaen <xucaen@xxxxxxxxx> Date: Tue, 16 Aug 2005 13:40:54 -0400 |
Hi, I just had a thought: A new assembler should be compatible with the books that have aleady been written on 6502 assembler. Jim On 8/16/05, C. Bond <cbond@xxxxxxxxxxxxx> wrote: > > > > -----Original Message----- > From: "B. Watson" <atari@xxxxxxxxxxxxxx> > Sent: Aug 16, 2005 6:55 AM > To: stella@xxxxxxxxxxxxxxxxxx > Subject: Re: [stella] DASM wish list > > > On Mon, 15 Aug 2005, C. Bond wrote: > > > ...especially if your opcode list includes all > > the unofficial opcodes. In some cases you may have to rewrite your > source code > > to change labels such as SAX, DCP, etc. so they don't conflict with > opcodes. > > It might be better to simply separate labels from opcodes by a > formatting rule. > > (Maybe not, just a thought!) > > Illegal opcode support ought to be something you can turn off, either > from the command line or with a directive in your source. At one time > there was talk of doing this in DASM, but I can't remember whether it > actually happened... > > > Another issue has to do with using opcode syntax such as LSR A and > > ROL A. If your assembler simply requires LSR or ROL, you can free > > up 'A' for use as a label, otherwise it becomes a reserved symbol. > > I don't think anyone who codes for the VCS also smokes crack, so we > don't have to worry about that: non-crackheads know better than to use > a label that conflicts with a register name! Just because something's > allowed doesn't mean it's a good idea, and I'm willing to bet we won't > run into any old code that has labels called A, X, or Y... > > [snip] > > In fact, I have bet that: I unconditionally treat A, X, Y, S, and PC as > registers in the Stella debugger. I thought about it a lot, and decided > that the inconvenience of having to type a "sigil" character (maybe ".A" > or "%A" for accumulator, as opposed to just plain "A") doesn't outweigh > the possible compatibility problems dealing with a drug-influenced > label called "A"... Everyone's going to have to refer to the accumulator > a zillion times, but only the insane people are going to have a label > called "A". I won't punish the many for the crimes of the few. > > --------------- > > Well, in my post I did not state a preference. I only pointed out that > there > are tradeoffs. However, I certainly don't recommend making things easier > for "crackheads" or the "insane". You have a clear concept of what is > convenient for the many and what weighs more heavily than what in > assembler syntax specifications. I have no argument against your > preferences, I simply pointed out as you did, that some decisions involve > the selection of reserved symbols. > > > > -- > B. > Archives (includes files) at http://www.biglist.com/lists/stella/archives/ > Unsub & more at http://stella.biglist.com > > > Archives (includes files) at http://www.biglist.com/lists/stella/archives/ > Unsub & more at http://stella.biglist.com > > -- I am Sci Fi Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://stella.biglist.com
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