chipKIT® Development Platform

Inspired by Arduino™

6502 simulator

Created Thu, 26 Feb 2015 23:58:27 +0000 by nroff-man

nroff-man

Thu, 26 Feb 2015 23:58:27 +0000

Hi :-)

Contrary to my upgrade of the chipKIT Pi to the MX270 at 48 MHz now I demonstrate how we can slow down the chipKIT Pi by simulating an 8-bit MPU (micro-processing unit) from yesteryear.

The chosen device is a 6502, mostly because I am familiar with it and also because I started work on this before and now this project is concluded.

The method to do this on the chipKIT Pi is documented here: http://wiki.kewl.org/dokuwiki/projects:ape65

Once up and running you can connect using `picocom' to the virtual MPU which has an assembly code monitor interface which you may or may not be familiar with (this depends on how ancient you are) :-)

Have fun, bye bye

Jacob Christ

Mon, 02 Mar 2015 04:13:57 +0000

Way cool... Can you emulate the Antic chip of an Atari 800 next?

Jacob

nroff-man

Mon, 02 Mar 2015 19:18:35 +0000

hi

Way cool... Can you emulate the Antic chip of an Atari 800 next? Jacob

I am sorry to say that I hardly know a thing about the ATARI Antic and have no idea how to emulate it.

What I do know is I had an 800XL which was among a number of computers I threw to the rubbish or gave away over 10 years ago which does make me sad. The only 8-bit computer I have now is a Commodore plus/4 which I got on eB*y.

This simulator on the ChipKIT Pi emulates the MPU and an 8-bit I/O port for the LEDs and the switch input and few GPIOs. It could be possible to extend it for video, perhaps the plus/4 TED chip but it would take the work of someone really dedicated, I am not sure that sounds like me :-)

Thanks, bye-bye

Jacob Christ

Mon, 02 Mar 2015 20:01:21 +0000

It was a tongue in cheek request...

I have an Atari 128XL and an Atari 1040ST holding down some cardboard on some shelves in my garage.

Jacob

nroff-man

Mon, 02 Mar 2015 20:49:47 +0000

Hi

It was a tongue in cheek request...

At the very least my copy of the `Programmer's Reference Guide the ATARI 400/800 Computers" got pulled off the book shelf for the first time in years :-)

The book doesn't seem to go into great detail about the ANTIC.

I have an Atari 128XL and an Atari 1040ST holding down some cardboard on some shelves in my garage. Jacob

I have never used them but did program the ANTIC successor, called the COPPER on an Amiga.

Simulating the 68000 MPU does sound interesting, it's a legendary MPU and anyone exposed to it would have loved programming it.

Hmm.

Bye-bye :-)

nroff-man

Tue, 03 Mar 2015 00:36:34 +0000

Hi.

I am not a great fan of BASIC but of course used it when young and have now added EhBASIC for 6502 to the PIC32 versions of this simulator.

EhBASIC was written in 6502 assembly code and runs on the virtual MPU. It seems to work as expected but not much testing done as yet.

I will add some documentation to my wiki later.

Here is a demo.

MCS 6502 Simulator & Debugger.
------------------------------
D.M.Broad.(c)
August 1989 & February 2015.

EhBASIC at $FF80 by Lee Davison

APE65 - Enter ? for HELP
APE65 - Enter GFF80 for BASIC

   PC  SR AC XR YR SP NV.BDIZC
; 0000 30 00 00 00 FF ..11....
GFF80

6502 EhBASIC [C]old/[W]arm ?

Memory size ? 8192

7423 Bytes free

Enhanced BASIC 2.22

Ready
10 PRINT "CHIPKIT RULEZ OK ";
20 GOTO 10
RUN
CHIPKIT RULEZ OK CHIPKIT RULEZ OK CHIPKIT RULEZ OK
Break in line 10
Ready

nroff-man

Mon, 09 Mar 2015 12:19:29 +0000

hi

@majenko

this simulator now works on the SDXL board and is loaded using via usb boot loader and is not stand-alone.

I have not completed work on this as yet. there is no virtual i/o port. for example, and this will come later.

the console is on UART2 as before, it would be good to somehow reuse the virtual com port from the boot loader but I have no idea about that as yet.

bye-bye

pito

Mon, 16 Mar 2015 18:08:16 +0000

fyi - http://forum.arduino.cc/index.php?topic=193216.msg2113719#msg2113719 :)

nroff-man

Mon, 16 Mar 2015 20:08:29 +0000

lo

fyi - http://forum.arduino.cc/index.php?topic=193216.msg2113719#msg2113719 :)

That seems to be something called FAKE6502 and it looks buggy.

Try this test suite, see how it goes. [url]https://github.com/Klaus2m5/6502_65C02_functional_tests[/url]

Bye-bye

majenko

Mon, 16 Mar 2015 21:38:25 +0000

I know it's not 6502, but the vastly superior Z80, but all this talk of retro home computers gave me a yearning...

So I knocked up this little animation on a MAX32 ;)

https://youtu.be/eon64wl8hY0

nroff-man

Mon, 16 Mar 2015 22:03:00 +0000

Hi

I know it's not 6502, but the vastly superior Z80, but all this talk of retro home computers gave me a yearning... So I knocked up this little animation on a MAX32 ;) https://youtu.be/eon64wl8hY0

If that video took about 15 minutes longer and ended with a loading failure then it would have been more realistic :-)

I had a ZX81 and wobbly RAM pack in around 1984, it was hopeless. I think I have the 1K flight simulator on cassette perhaps you can port it to PIC32 TFT?

Cya! :-)

pito

Tue, 17 Mar 2015 00:35:46 +0000

Nice :) I owned ZX81 (w/ diy 16kB ram) and Sinclair Spectrum too. I can still remember the loading from cassettes well :lol: