Working on a Wiki for C64/128 programming related info.  At first, it was meant just for myself as a personal reference, but since its out there, might as well provide the link.  ALL of the info there has been obtained from somewhere else (including here).  I wish indeed I had all that knowledge, but thats exactly why I need a reference.

http://commodore64.wikispaces.com

Right now, its a private wiki, meaning only those I provide access to can edit the pages.  Let me know if you want to contribute.  For now, Im just trying to get it off the ground.

Being somewhat bored this evening, I decided to pit Sargon II against the Chess Titans app that comes with Vista.  Im pleased to say that Sargon beat the snot out of Chess Titans.  In fairness to Vista, CT was set to "Basic" or "Novice".  But still... they ought to be ashamed

Reposted here as its a "trick":

I found this from the Ahoy May 87 issue:

1 REM C64 version
2 FOR J = 679 TO 679+22:READA:POKEJ,A:NEXTJ:END
3 DATA 104,104,169,255,133,74,32,138,163,154,201,141
4 DATA 240,3,76,224,168,104,104,104,104,104,96

1 REM C128 version
2 FOR J = 4864 TO 4864+23:READA:POKEJ,A:NEXTJ:END
3 DATA 104,104,104,104,169,141,32,170,79,240,5,162
4 DATA 12,76,60,77,32,80,80,160,5,76,89,80

To demonstrate how to get out of requiring a RETURN statement, after you run one of the above, try this:

10 GOSUB 20
20 A=A+1:PRINT A:SYS 679:GOTO 10

(substitute 4864 if using a 128).  What youll find instead of an out of memory error, is that the need for a RETURN has been removed from the stack.

Hey man,

I found this from the Ahoy May 87 issue:

1 REM C64 version
2 FOR J = 679 TO 679+22:READA:POKEJ,A:NEXTJ:END
3 DATA 104,104,169,255,133,74,32,138,163,154,201,141
4 DATA 240,3,76,224,168,104,104,104,104,104,96

1 REM C128 version
2 FOR J = 4864 TO 4864+23:READA:POKEJ,A:NEXTJ:END
3 DATA 104,104,104,104,169,141,32,170,79,240,5,162
4 DATA 12,76,60,77,32,80,80,160,5,76,89,80

To demonstrate how to get out of requiring a RETURN statement, after you run one of the above, try this:

10 GOSUB 20
20 A=A+1:PRINT A:SYS 679:GOTO 10

(substitute 4864 if using a 128).  What youll find instead of an out of memory error, is that the need for a RETURN has been removed from the stack.

The gosub issue is a matter of moving the stack pointer, but Id be cautious there for obvious reasons. If it does work, I think reliability would be a concern.  Perhaps a better option would be calculated goto's. (theres code to do that - see April 1988 Gazette : http://www.commodore128.org/gaztype.html)

The other is about knowing what to AND and OR.  I may be speaking the obvious to you, but here's a quick rundown:

      101001 
AND 000001
-----------
      000001

So AND-ing something is used to confirm if a single bit is set.  The test above, I AND it with the bit I want to look for.  If the answer is 1 (or another value depending on the bits you are testing), then it is true.  This translates to alot of  IF PEEK(XXXX) AND 128 (or whatever) THEN...

IF PEEK(XXX) AND 1 = 1 (Test if bit 0 is on - right-most bit)
IF PEEK(XXX) AND 2 = 2 (Test if bit 1 is on)
IF PEEK(XXX) AND 4 = 4 (Test if bit 2 is on)
IF PEEK(XXX) AND 8 = 8 (Test if bit 3 is on)
IF PEEK(XXX) AND 16 = 16 (Test if bit 4 is on)
IF PEEK(XXX) AND 32 = 32 (Test if bit 5 is on)
IF PEEK(XXX) AND 64 = 64 (Test if bit 6 is on)
IF PEEK(XXX) AND 128 = 128 (Test if bit 7 is on - left-most bit)

You can combine tests, by adding their position...

IF PEEK(XXX) AND 3 = 3 (Test if bit 0 and bit 1 is on)

As for OR...

       111110
OR   111111
------------
       111111   ORing a value turns a bit on (here we turned on all bits)

Which is why you see alot of POKE XXXX, PEEK(XXXX) OR 255 (or whatever).  Just an easy way to turn on a single bit, or multiple bits

Same here.  My first was a 1660.  It was like discovering a new dimension or something.  Listen to a dial process, then wow... characters starting to stream across my screen.  From some other computer out there.  awesome.  Then a 1670 and the game was on.  Soon I found that 2400 Aprotek modem, which to this day is still an oddity to me as my understanding is that a 64 cant reliably do 2400 bps, yet it managed to do a very good job.  I never got a Switflink or T232 - after the 128 I went to an Amiga 500, where 19.2 was the norm.

So if there are any other Tennessee folks out there considering a C= board, Im your first caller.  I tossed the idea around of running my own as stated, but again.. I think I have more fun being a caller.

Speaking of connectivity though... I build a 7404 adapter for the userport, and it worked fine awhile back.  When I recently got everything out again, I couldnt get a connection.  Can you guys help refresh my memory - do I need a null modem adapter as well? (seems logical that I would)  I thought for sure I would have packed that up with everything if I needed it, but I cant find it in that stuff anywhere. 

I "ran" one back in the day too.. I was 15... and the best I could do was hook it up after midnight - all my parents would allow... until one night when I forgot to unplug the other phone extension :/  The only way to get callers back then like that, was to put up warez... but at 15, I couldnt even afford that.  Today, I probably wouldnt run one, but rather enjoy just being a caller.

Thing is -  and maybe its just wishful thinking - but I would revert back 100% to dial up BBSing, if there were more boards, and people would join in the message boards.  I suppose we're really spoiled by the speed of the net, instant downloads, etc.  IMHO, even Qlink's resurrection has been hurt by the IRC channel link.  Evil internet... :/

Now excuse me while I bittorrent the entire Gamebase 64...

Anyone have d64s of this?

Ok, in BASIC try this:

PRINT 3 = 3

The answer is, of course, true, or '-1'

Why is the following false (0)

PRINT 3 = SQR(9)

The real answer requires more than just one sentence

Hey guys, just tossing out a programming challenge...hope you guys are open to it...

Ive been working with reading the disk directory using the U1 command, and its just not fast enough for an app Im working on.  Id like to get some more speed out of it.  So the challenge is this:

1. Write a reusable subroutine in BASIC only
2. For now, just a 1541 disk (no 1581s or 1571s)
3. Return the disk name in DN$ and disk ID in ID$
4. Return an array of filenames on the disk in FI$()
5. Use FAST mode
6. Uncompiled

Im using TI$ for timing (not the best, but it gives me some idea for comparison).  I have my code down to 11 seconds for 12 files on disk, and to me this is way too slow.

Any takers?

If a window is established on the 128, all normal printing occurs within it. To get out of the window, poke to location 235 as in:

110 WINDOW 0,19,39,20
120 PRINT"IN WINDOW" : GETKEYA$
130 POKE 235,1: PRINT
140 PRINT"OUT OF WINDOW": GETKEY A$
150 POKE 235,10: PRINT
160 PRINT"INSIDE AGAIN"

paraphrased from an old RUN magazine issue

Is Jeri ever online? 

Ive looked around the net at various 1541 interfaces, and one thing Im confused about... why hasnt someone simply (and i use that term very loosely) taken the motherboard out of a 1541, and modified it to write to an HD or SD card, etc.. meaning have something actually intercept the low level drive manipulations and translate them for a different device.  Seems this would give really good compatibility.  Since the 1541 is essentially a computer in its own right, it seems that interfacing to it directly should be possible.  Thoughts?

Where do you find this stuff? lol..

At first glance, it does look rather strange.  But I would not want to appear to discredit someone's good work for the community. 

Quote from: RobertB on October 20, 2008, 11:01 AM
     Heh, this is what we charge out of FCUG storage (if the item is there), box or no:


C128D - 30.00

Hmm... might have to get in touch with ya on that one   hehehe

Without quoting Golan (too many inner quotes):

The rationale for something like this, is quite similar to coin collector guides, stamp collector guides, etc.  Just a rule of thumb.  Certainly the Ebay market  dictates what something is worth, sure.  But as you noticed, for a C65 or a CMD HD, I havent a fair clue what it should run.  Understanding rarity is really a matter for people who have been doing this for awhile. I think I was in the middle of a irc chat regarding some kind of book about copy protection, and how rare it was... seeing it in a listing, without knowing, I would think it silly that someone is posting a booklet for upwards of $150.  So it's more than just what its worth to the individual - there is definitely a real value being attributed to these things in the Commodore circles.

But your input does help as I know you've been doing this for a long time.  I'll go back and revise those numbers based on the input.

BTW... $7000 for the C65? Whoa.

Golan!

You're supposed to be SELLING, not BUYING!

Guys - we really need to have an intervention....

heheh.. I guess I cant talk.. I bought a 1750 clone today.. paid the buy it now price so I wouldnt have to fight people on the bid war.  Thats fine tho, it's an investment.  I have a naked 1750 (without case) that I will put up for sale afterward.  I dont like to hoard stuff.  Well, not usually...

Hey, so I pulled my 7404 interface out of storage (been awhile).  Found one of my leads needed resoldering...did that, and hooked it up.  Ran a serial line from the interface to the PC, but the PC cant seem to talk to the interface.. nothing.  I cant remember - do I need a null modem interface between the PC and the 7404 interface?  I vaguely remember that I had one, but cant find it. (I would think I would have stored them together if I did need it).  But it makes sense that I would.

Have any of you seen this site:

http://c64preservation.com/

?

Im a little confused.  This person wants you to scan your originals, and send the image to him.  He doesnt post links to download the files (that I can see).  Is this "preservation", just for him?

In that case, I have a Commodore Hardware Preservation site Im working on.  Send me your hardware. :/

Quote from: Andrew Wiskow on October 19, 2008, 02:27 PM
I prefer my method for determining what something is worth.  Post it on eBay with a starting bid of 99¢.  Whatever it sells for, that's what it's worth.

BTW, based on this method, a boxed C2N with manual is worth 99¢.  :|

True...   This is more of an average to know when waiting for the next auction might be a better idea.

But you know, despite the wacky pricing, if it not for something like Ebay, alot of this stuff would end up in a landfill.  What is needed is a value/rarity list for Commodore equipment, that reasonable people would stick to when putting out an auction.  Would help answer the question "whats my ... worth?", and would help it sell quicker.  Much like stamp collecting or coin collecting.  As it is, its luck of the draw, whatever-I-can-get-out-of-it.

Toying with the idea, here's my stab at it (USD), assuming used (fair) condition, cables, but without original boxes (add 10-20%).

Machines: (excluding PETs)

VIC20 - 10.00
+4 - 25.00
C16 - 35.00 (relatively rare on ebay it seems)
C64 - 20.00
SX-64 - 80.00
C64C - 30.00
C128 - 40.00
C128D - 90.00
C65 - 500.00+ (?)

Drives:

C2N - $5.00
1541 - 8.00
1541C - 15.00
1541-II - 20.00 (due to multi-use of power adapter / 1581)
1551 - 40.00 (never seen one... guessing at this number)
1570 - 30.00 (rare?)
1571 - 15.00
1581 - 80.00
CMD HDs - $100-$300

Display:

Monitors (Composite Only) - $10
Monitors (Comp & RGBI) - $30

Other:

REU (all) - $60-$80
Printers - < $10 (consumables are hard to find)
Modems (300/1200 bps) - < $5

Software:

For heavens sake... please acknowledge that D64 images exist of almost everything... keep it low unless you have all original manuals, boxes, etc

My $0.02.  Many of you have been doing this for alot longer than me, so feel free to red-pen my numbers.  Certainly people will pay for what its worth to them, but this ought to give folks an idea on what the hardware is really worth on the ebay market.

How bad am I?

Im seriously thinking about THIS auction:

http://cgi.ebay.com/Vintage-PC-XT-AT-Commodore-Printer-Keyboard-Monitor_W0QQitemZ180298267250QQcmdZViewItem?hash=item180298267250&_trkparms=72%3A1205|39%3A1|66%3A2|65%3A12|240%3A1318&_trksid=p3286.c0.m14

JUST for the Commodore 128D.

I spoke to the guy - he doesnt think the 128D even works.

Im still thinking about it.

Like this?

http://cgi.ebay.com/Commadore-64-computer-with-monitor-and-power-supply_W0QQitemZ330103292764QQcmdZViewItem?_trksid=p3286.m20.l1116

This is one of my favorite Ebay games.. find the most ludicrous C= auction. lol

But... Ebay is not the only place in town for this game...try this one:

http://www.amazon.com/Commodore-Computer-Video-Game-System/dp/B000FHHSDU/ref=sr_1_3?ie=UTF8&s=videogames&qid=1224225457&sr=8-3