Denial

When you program in Basic on a VIC20, often speed and/or memory can be a issue. One trick to save memory and improve speed is to put as many statements as possible, separated by colons, on one Basic line. Each Basic line has an overhead of 4 bytes, so each line you save is 4 bytes you save. When per...

Copying memory blocks this way may also be used to manipulate arrays. - Swapping the contents of two arrays (using a string as the intermediate buffer). - (Re-)Initializing an array (e.g. with the contents of a string of 0's (STRING$(sizeof(array),0)). When the arraysize is 255 bytes or less, this c...

Another thing to note is that BIT# in 65C02 does not modify N or V, but only Z.
Where in 6502 the BIT instructions do set N and V corresponding B7 and B6 of the memory location

Regards,

Wim.

The most interesting values are probably the powers of 2, they're given here: $01 $C390 $02 $C39B $04 $C3E7 $08 $C3B9 $10 $C338 $20 $C1A1 $40 $CB5A $80 $C018 In character ROM, at location $8268 is a list of powers of two in descending order, and at $8270 in ascending order. These lists make it also...

change line 260 to

Armando. What memory configuration are you using ? Line 260 is assuming you have 3.5k or maybe 6.5k, but not +8k or +16k. What I think happens is that the POKEs in line 260 overwrite the memory space for simple variables, and subsequently Z cannot be found anymore, resulting in Z=0. In line 270 a A(...

Hello Armando,

Can you make that program available to us ?

Regards,

Wim.

Here is the WimBasic version. Brought it down to 1912 bytes, 37 lines.
It autostarts in VICE.

Regards,

Wim.

Hi Victragic, I suggest to make the sorting routine a bit faster / obsolete: Replace 73 t=0:n=1 74 ifd%(n,p)<d%(n-1,p)thent=d%(n-1,p):d%(n-1,p)=d%(n,p):d%(n,p)=t:ifn>1thenn=n-1:goto74 75 n=n+1:ifn<13then74 76 return with 73 n=i 74 ifn<12-rthend%(n,p)=d%(n+1,p):n=n+1:goto74 75 d%(n,p)=99 76 return an...

Hello Robbie,

On a VIC with no further extensions, the key combination SHIFT-RUN/STOP does this. Only from tape, though.
On VICE, there is an 'Autostart' feature that loads and runs a program from disk #8.


Regards,

Wim

Hello srowe

Thanks to strace , I now see that VICE opens files with the syscall openat() and does not use the O_ASYNC flag that is needed when addressing a pipe.

Regards,

Wim.

All, Has anyone ever tried to integrate VIC with the host platform through the filesystem ? That is, in linux do: ln -s /dev/urandom rnd xvic and then in VICE 10 OPEN1,8,0,"RND" 20 GET#1,A$:IFA$=""THENA$=CHR$(0) 30 PRINTASC(A$) 40 IFST=0THEN20 50 CLOSE1 This works. Also the /proc...

This is the WimBasic version of the Sokoban game that Mike developed. I have added a rudimentary timer and counters for moves and pushes. Run BOOT to load and run WimBasic, that subsequently reconfigures the VIC and starts the game. The following WimBasic features were used: HIMEM INPUTLINE# (the sc...

I can follow the "state-analyze-move" approach and honor it, next to my pragmatic approach. Still a PEEK is done that is possibly "out-of-bounds". And because the screen memory, conveniently, doesn't start at 0, this doesn't lead to an ILLQUANT error. During the analysis it is di...

Yes. Well. The setup of the Sokoban game, with its bitmasks to signify the contents of a location is a great find. But, in the algorithm: What is the use of trying to get information on a second-adjacent location if you're not even sure you're going to impact it ? Because, maybe the first-adjacent l...