define instruction from easy 6502 not working

[lerugray]

Assembler doesn't recognize the same instruction from the tutorial

[BigEd]

Which assembler are you trying to use? Each assembler does have unique choices for how to express a program, and easy6502 is no exception!

[lerugray]

I tried downloading the 6502 JS Assembler, it would not recognize the Define instruction as used in the tutorials.

…

On Wed, Nov 22, 2017 at 8:12 AM, BigEd ***@***.***> wrote: Which assembler are you trying to use? Each assembler does have unique choices for how to express a program, and easy6502 is no exception! — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#7 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AOZWIeJ0ZT07rFBPYSBXHaAJA9jMlNl3ks5s5B3MgaJpZM4Qmb5Q> .

[BigEd]

Do you mean http://www.6502asm.com/ ? If so, it has no define, so from the examples we see the tactic is to use a label:

* = $hhhh
name

[BigEd]

Oops sorry I have just realised that I was confused between easy6502 and 6502js. Let me look into this. We do know the two assemblers have diverged. My own fork of 6502js is different again.

[lerugray]

OK Cool thank you, yeah I was hoping that there was one of these I could download to practice assembly on my own, like building snake from scratch with the embedded screen you guys had in easy 6502 if this is possible, plz lemme know, I know easy6502 had a define instruction for their snake example

…

On Sun, Nov 26, 2017 at 9:55 AM, BigEd ***@***.***> wrote: Oops sorry I have just realised that I was confused between easy6502 and 6502js. Let me look into this. We do know the two assemblers have diverged. My own fork of 6502js is different again. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#7 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AOZWIQqk8gIm7lsgTLIoDC7yWc39vo2Zks5s6XvlgaJpZM4Qmb5Q> .

[lerugray]

for example, trying to use the easy 6502 assembler downloaded from easy 6502 in the tutorial, they use (define) as a means of declaring constants/variables. Upon downloading the Assembler though, the define instruction stops working. How would I still define variables/constants?

…

On Sun, Nov 26, 2017 at 4:11 PM, Raymond Liberto ***@***.***> wrote: OK Cool thank you, yeah I was hoping that there was one of these I could download to practice assembly on my own, like building snake from scratch with the embedded screen you guys had in easy 6502 if this is possible, plz lemme know, I know easy6502 had a define instruction for their snake example On Sun, Nov 26, 2017 at 9:55 AM, BigEd ***@***.***> wrote: > Oops sorry I have just realised that I was confused between easy6502 and > 6502js. Let me look into this. We do know the two assemblers have diverged. > My own fork of 6502js is different again. > > — > You are receiving this because you authored the thread. > Reply to this email directly, view it on GitHub > <#7 (comment)>, > or mute the thread > <https://github.com/notifications/unsubscribe-auth/AOZWIQqk8gIm7lsgTLIoDC7yWc39vo2Zks5s6XvlgaJpZM4Qmb5Q> > . >

[BigEd]

Just started looking at this. I see you can use the same kind of workaround, abusing the label mechanism to define a symbol:

* = 255
mask:

* = $600
start:
nop
lda mask
nop

[lerugray]

How would you use this technique in something like a constant? Lets say for example I wanted to set sysRandom = $fe (the RNG on the mock 6502) *=255 - is this setting mask to 255 decimal? I'm a little confused as to how this example works in practice, thanks for the help

…

On Mon, Nov 27, 2017 at 1:01 PM, BigEd ***@***.***> wrote: Just started looking at this. I see you can use the same kind of workaround, abusing the label mechanism to define a symbol: * = 255 mask: * = $600 start: nop lda mask nop — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#7 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AOZWIY97nMZy4uBFvwi884n2isdjzom6ks5s6vj0gaJpZM4Qmb5Q> .

[BigEd]

Here's a slight expansion of the example:

* = 127
mask:

* = $fe
sysRandom:

* = $600
start:
nop
lda mask
and sysRandom
nop

and the disassembler says we got this:

Address  Hexdump   Dissassembly
-------------------------------
$0600    ea        NOP 
$0601    a5 7f     LDA $7f
$0603    25 fe     AND $fe
$0605    ea        NOP 

So, it's a little ugly, and it takes two lines to make each define, but I think it works generally.

[BigEd]

(However, I notice the tactic fails for immediate values. I should have written
lda #mask
but that turns out not to work at all.)

[lerugray]

Aghh that's unfortunate, was going to use this idea for costants related to collision, if there's a workaround, kindly let me know, thx!

…

On Nov 27, 2017 13:33, "BigEd" ***@***.***> wrote: (However, I notice the tactic fails for immediate values. I should have written lda #mask but that turns out not to work at all.) — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#7 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AOZWIZmu_RS1174kTfSBEKHzU4ZPjAEJks5s6wCIgaJpZM4Qmb5Q> .

[lerugray]

oh and just for context, I'm trying to build snake/pong in the assembler without using the help of the tutorial, so i assume even if reformatted for the above hack, that code still wouldnt assemble given the #immediatevalue error.

…

On Mon, Nov 27, 2017 at 1:35 PM, Raymond Liberto ***@***.***> wrote: Aghh that's unfortunate, was going to use this idea for costants related to collision, if there's a workaround, kindly let me know, thx! On Nov 27, 2017 13:33, "BigEd" ***@***.***> wrote: > (However, I notice the tactic fails for immediate values. I should have > written > lda #mask > but that turns out not to work at all.) > > — > You are receiving this because you authored the thread. > Reply to this email directly, view it on GitHub > <#7 (comment)>, > or mute the thread > <https://github.com/notifications/unsubscribe-auth/AOZWIZmu_RS1174kTfSBEKHzU4ZPjAEJks5s6wCIgaJpZM4Qmb5Q> > . >

[BigEd]

I think we'd need to bring the whole 'define' mechanism in from easy6502 to 6502js.

Meantime, could you work using a local copy of easy6502 instead of using 6502js? I tend to try out small snippets just using the first emulation window - the snake is way down the file and needn't distract you.

[lerugray]

Yes that would be perfect, could you link me to the appropriate place to grab the easy 6502 engine? Tha k you so much

…

On Nov 27, 2017 13:57, "BigEd" ***@***.***> wrote: I think we'd need to bring the whole 'define' mechanism in from easy6502 to 6502js. Meantime, could you work using a local copy of easy6502 instead of using 6502js? I tend to try out small snippets just using the first emulation window - the snake is way down the file and needn't distract you. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#7 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AOZWIW5Y1MDr5k0k7ZYvBDwur327LbNiks5s6wYAgaJpZM4Qmb5Q> .

[lerugray]

Oh wait I see what you mean, yeah that sounds good, please keep me posted as to when you add in define. Also curious, how do I reserve bytes for variables? For the nes, all I usually will do is (nesasm) ballspeedx: .rs 1

…

On Nov 27, 2017 13:57, "BigEd" ***@***.***> wrote: I think we'd need to bring the whole 'define' mechanism in from easy6502 to 6502js. Meantime, could you work using a local copy of easy6502 instead of using 6502js? I tend to try out small snippets just using the first emulation window - the snake is way down the file and needn't distract you. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#7 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AOZWIW5Y1MDr5k0k7ZYvBDwur327LbNiks5s6wYAgaJpZM4Qmb5Q> .