6502.org Forum Projects Code Documents Tools Forum
It is currently Fri Nov 15, 2024 9:29 am

View unanswered posts | View active topics


Board index » 6502.org Users Forum » Newbies

All times are UTC




Post new topic Reply to topic  Page 3 of 3
  [ 45 posts ]  Go to page Previous  1, 2, 3
  Previous topic | Next topic 
Author Message
barrym95838
PostPosted: Tue Nov 27, 2018 8:51 pm 
Offline
User avatar

Joined: Sun Jun 30, 2013 10:26 pm
Posts: 1949
Location: Sacramento, CA, USA
BigDumbDinosaur wrote:
At least you guys had reference manuals to work with. When I started with the 6502, manuals had yet to be written. I worked off typewritten notes gotten from MOS Technology.

I'll bet you're one of those guys who used to walk to school in the snow back in the day. :wink:

_________________
Got a kilobyte lying fallow in your 65xx's memory map? Sprinkle some VTL02C on it and see how it grows on you!

Mike B. (about me) (learning how to github)
Top
 Profile  
Reply with quote  
BillO
PostPosted: Tue Nov 27, 2018 9:14 pm 
Offline
User avatar

Joined: Fri Dec 12, 2008 10:40 pm
Posts: 1007
Location: Canada
barrym95838 wrote:
I'll bet you're one of those guys who used to walk to school in the snow back in the day. :wink:


Didn't we all. Up hill both ways too.

_________________
Bill
Top
 Profile  
Reply with quote  
BigDumbDinosaur
PostPosted: Tue Nov 27, 2018 9:32 pm 
Offline
User avatar

Joined: Thu May 28, 2009 9:46 pm
Posts: 8489
Location: Midwestern USA
BigEd wrote:
I think learning by doing is the best way for most people, it's a question of how much support you get, how much confidence you have, and how much effort it then takes.

Being motivated to learn is essential as well. :D

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!
Top
 Profile  
Reply with quote  
whartung
PostPosted: Tue Nov 27, 2018 10:18 pm 
Offline

Joined: Sat Dec 13, 2003 3:37 pm
Posts: 1004
barrym95838 wrote:
BigDumbDinosaur wrote:
At least you guys had reference manuals to work with. When I started with the 6502, manuals had yet to be written. I worked off typewritten notes gotten from MOS Technology.

I'll bet you're one of those guys who used to walk to school in the snow back in the day. :wink:

Back in BDDs day, he only has 0's to work with, they hadn't invented the 1's yet.
Top
 Profile  
Reply with quote  
barrym95838
PostPosted: Wed Nov 28, 2018 12:54 am 
Offline
User avatar

Joined: Sun Jun 30, 2013 10:26 pm
Posts: 1949
Location: Sacramento, CA, USA
whartung wrote:
Back in BDDs day, he only has 0's to work with, they hadn't invented the 1's yet.

I have recently been able to conclude that Base 1 arithmetic can present some unique challenges.

_________________
Got a kilobyte lying fallow in your 65xx's memory map? Sprinkle some VTL02C on it and see how it grows on you!

Mike B. (about me) (learning how to github)
Top
 Profile  
Reply with quote  
BigDumbDinosaur
PostPosted: Wed Nov 28, 2018 2:54 am 
Offline
User avatar

Joined: Thu May 28, 2009 9:46 pm
Posts: 8489
Location: Midwestern USA
barrym95838 wrote:
BigDumbDinosaur wrote:
At least you guys had reference manuals to work with. When I started with the 6502, manuals had yet to be written. I worked off typewritten notes gotten from MOS Technology.

I'll bet you're one of those guys who used to walk to school in the snow back in the day. :wink:

A couple of times I did while I was in high school when I overslept and missed the bus. It was a 1.9 mile walk to get there. :D

whartung wrote:
Back in BDDs day, he only has 0's to work with, they hadn't invented the 1's yet.

I tried to file a patent on 1s but someone beat me to it.

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!
Top
 Profile  
Reply with quote  
BillO
PostPosted: Wed Nov 28, 2018 2:00 pm 
Offline
User avatar

Joined: Fri Dec 12, 2008 10:40 pm
Posts: 1007
Location: Canada
BigEd wrote:
I think learning by doing is the best way for most people, it's a question of how much support you get, how much confidence you have, and how much effort it then takes.

I agree. When I learned it was by doing, but there was little support for it. It was a hobby so was low on the importance scale to those around me. There were no clubs nearby, no others in my circle that were interested, and certainly nothing like 6502.org. This place is gold. Good support, like what is available from this site, should help bolster confidence and bring motivation.

_________________
Bill
Top
 Profile  
Reply with quote  
cbmeeks
PostPosted: Wed Nov 28, 2018 2:52 pm 
Offline
User avatar

Joined: Wed Aug 17, 2005 12:07 am
Posts: 1250
Location: Soddy-Daisy, TN USA
BigDumbDinosaur wrote:
barrym95838 wrote:
BigDumbDinosaur wrote:
At least you guys had reference manuals to work with. When I started with the 6502, manuals had yet to be written. I worked off typewritten notes gotten from MOS Technology.

I'll bet you're one of those guys who used to walk to school in the snow back in the day. :wink:

A couple of times I did while I was in high school when I overslept and missed the bus. It was a 1.9 mile walk to get there. :D

whartung wrote:
Back in BDDs day, he only has 0's to work with, they hadn't invented the 1's yet.

I tried to file a patent on 1s but someone beat me to it.



OT...sorry...but that made me chuckle.

I used to have an uncle that joked about how old he was. The joke would be:

Me: "James, what's your SSN?"
Uncle James: "One."

LOL

Of course, I had to have a bit of fun about how old I am to my granddaughter. She's convinced I rode a horse-n-buggy to school. lol

_________________
Cat; the other white meat.
Top
 Profile  
Reply with quote  
JimBoyd
PostPosted: Wed Nov 28, 2018 9:29 pm 
Offline

Joined: Fri May 05, 2017 9:27 pm
Posts: 895
barrym95838 wrote:
I have recently been able to conclude that Base 1 arithmetic can present some unique challenges.

You didn't by any chance set BASE to one while using Forth?
Top
 Profile  
Reply with quote  
barrym95838
PostPosted: Thu Nov 29, 2018 2:32 am 
Offline
User avatar

Joined: Sun Jun 30, 2013 10:26 pm
Posts: 1949
Location: Sacramento, CA, USA
JimBoyd wrote:
You didn't by any chance set BASE to one while using Forth?

Not exactly, but I get the gist of your train of thought. 8)

_________________
Got a kilobyte lying fallow in your 65xx's memory map? Sprinkle some VTL02C on it and see how it grows on you!

Mike B. (about me) (learning how to github)
Top
 Profile  
Reply with quote  
JimBoyd
PostPosted: Sun Dec 02, 2018 11:12 pm 
Offline

Joined: Fri May 05, 2017 9:27 pm
Posts: 895
GARTHWILSON wrote:
Yep. This is definitely a contact sport. :lol:

Does that mean I'm an athlete? :D
Top
 Profile  
Reply with quote  
BitWise
PostPosted: Mon Dec 03, 2018 9:48 am 
Offline
User avatar

Joined: Tue Mar 02, 2004 8:55 am
Posts: 996
Location: Berkshire, UK
JimBoyd wrote:
GARTHWILSON wrote:
Yep. This is definitely a contact sport. :lol:

Does that mean I'm an athlete? :D

No but you may occasionally get athletes foot.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs
Top
 Profile  
Reply with quote  
JimBoyd
PostPosted: Sun Jun 09, 2019 1:21 am 
Offline

Joined: Fri May 05, 2017 9:27 pm
Posts: 895
load81 wrote:
Dr Jefyll wrote:
Are you doing any assembly language coding of your own?


Yes, albeit simple stuff like changing boarder colors to simulate a phosopor display. Right now I'm writing a faux BSoD program for the C64. It's just a gag: a two byte memory address generated at random and a fake processor error. This is requiring me to figure out how to get a random number. (I haven't figured that out, yet.) The errors will be humorous. "Zero page has been eaten by a grue," that sort of thing.

If you're still interested in an 8 bit random number generator for the Commodore 64, here is a tip from the June 1986 issue of Ahoy! magazine.
Initialize voice 3 of the SID chip:
Code:
LDA #$FF
STA $D40F
LDA #$80
STA $D412

Read the random number:
Code:
LDA $D41B
Top
 Profile  
Reply with quote  
JimBoyd
PostPosted: Thu Jun 13, 2019 10:02 pm 
Offline

Joined: Fri May 05, 2017 9:27 pm
Posts: 895
Concerning the tip I provided, I don't know how random the value will be or how the VICE simulator stacks up to the real Commodore 64 SID chip concerning the randomness of the output.
Code:
// do the following once to initialize the generator.
LDA #$FF      // set SID's voice three frequency
STA $D40F     // high byte to maximum
LDA #$80
STA $D412     // set the noise waveform
   .
   .
   .
LDA $D41B     // read the value of the waveform
              // as often as needed.
   .
   .
   .
Top
 Profile  
Reply with quote  
White Flame
PostPosted: Mon Jul 01, 2019 5:54 am 
Offline

Joined: Tue Jul 24, 2012 2:27 am
Posts: 679
Here's also a fully software 0-255 8-bit PRNG, keeping a seed around and setting the accumulator to the next random number:
Code:
        lda seed
        beq doEor
         asl
         beq noEor ;if the input was $80, skip the EOR
         bcc noEor
doEor:    eor #$1d
noEor:  sta seed


The code can be smaller if a 1-255 output range is fine. There are wider PRNGs and other variants there as well.

_________________
WFDis Interactive 6502 Disassembler
AcheronVM: A Reconfigurable 16-bit Virtual CPU for the 6502 Microprocessor
Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 3 of 3
  [ 45 posts ]  Go to page Previous  1, 2, 3

Board index » 6502.org Users Forum » Newbies

All times are UTC


Who is online

Users browsing this forum: No registered users and 2 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
6502.org is an ongoing project by Mike Naberezny and contributors.