Javascript 6502 assembler and emulator

matsondawson · Post by **matsondawson** » Tue Jan 12, 2010 9:59 pm

This is a JS 6502 assembler and imaginary 6502 machine emulator I've been working on for a while. Still needs some polish, and doesn't work on Internet Explorer (never will until they become HTML5 compliant).

http://www.mdawson.net/asm6502/6502asm.php

I still have to add in keyboard, and support for character mapped displays.
And anyone using an underpowered machine may not get smooth scrolling.

Kweepa · Post by **Kweepa** » Wed Jan 13, 2010 12:20 am

Very cool.

Reminds me of this:
http://www.6502asm.com/
and
http://www.hedron.org/6502emu/6502emu.html

matsondawson · Post by **matsondawson** » Wed Jan 13, 2010 1:40 am

Ah yes, I saw them first but they were too slow.
Mine is heaps faster, has custom graphics resolutions, bit depths and syntax highlighting.

Kweepa · Post by **Kweepa** » Wed Jan 13, 2010 11:39 pm

I didn't mean to disparage your work!
It looks awesome.
It's like you've designed your ideal 8-bit computer! (Minus the sound.)

matsondawson · Post by **matsondawson** » Thu Jan 14, 2010 6:38 pm

I didn't think you were!

What I wanted to do was create a program that would enable me to create the perfect machine as I'd want it to be back in the 80's.

So the idea is, choose a cpu, and choose a resolution and bitdepth, then see how good it is. Also I thought it coul d be usefull for someone who was building a 6502 computer for fun to pre-test how the hardware could turn out.

I always wondered, what if the vic20 had a 16 colour raster mode and a little bit more ram.

I'm half considering adding a blitter device too.

rhurst · Post by **rhurst** » Fri Jan 15, 2010 6:04 am

Just a suggestion: make it run like this simply perfect machine ... for first phase, don't worry about cycle-exact raster timing to start with, just vertical sync timing (NTSC/PAL). At least you'll get a lot (but not all) of software to be able to test it against.

Then if you are successful and still motivated, make advancements for your dream machine from the lessons learned.

Kweepa · Post by **Kweepa** » Fri Jan 15, 2010 5:47 pm

rhurst wrote:Just a suggestion: make it run like this simply perfect machine ...

Errr... he already did that.
http://www.mdawson.net/vic20beta/vic20.php

rhurst · Post by **rhurst** » Sat Jan 16, 2010 8:43 am

I missed bookmarking that link earlier -- I recall now that it runs better with Google Chrome (which is the only reason why I have that browser on my Vista64 workstation). I think my brain is getting RAM errors ...

Thanks for the post!

rhurst · Post by **rhurst** » Sat Jan 16, 2010 3:40 pm

Typical results running Quikman, using

Google Chrome:

Code: Select all

JIT stats                       Performance stats
Compiled sub-sections:	1046	Emulation Speed:	750%
Compiled instructions:	4426	Real Speed:		100%
Delay-loops optimised:	   0		
LSR A's optimised:		   28	
ASL A's optimised:		   30

Firefox:

Code: Select all

Performance stats
Emulation Speed:  124%
Real Speed:        68%

Internet Explorer:
A SORRY message ...