@BB8, Your suggestion is good and even better than the optimizations from @fhw72.
It takes 2001525 cycles and thus, achieves 4032 Byte/s on a PAL C64.

CRC0 = $FB ; current value of CRC
CRC1 = $FC
CRC2 = $FD
CRC3 = $FE

CRC_START = $A000
CRC_COUNT = $2000

.macro CRC_createTableEntry value,byte ...

Thanks for your suggestions!

With the help of your proposal, @BigDumpDinosaur, the cycles to do a CRC32 of the BASIC ROM drop from 2,159,152 (= 3,738 Byte/s) to 2,059,534 (= 3,918 Byte/s).
@fhw72 optimised it on top of your code by re-arranging the code and using Y for indexed reading of the new ...

Hello,

I have a problem where I need a CRC32 on a memory-constraint 6502 system (no 65C02 or other allowed, just plain NMOS-6502). One the one hand, it should be somehow fast (which makes http://6502.org/source/integers/crc.htm not optimal), but also not to take too much space (LUT normally take ...

There is such a program in Polish (SYMULATOR 6510) and German (6510 Einzelschritt-Simulator) but writen in BASIC.
The Polish version is in the attachment.
The instructions are in the program, if you have any problems, I can translate them.
That's obviously the "Einzelschrittsimulator" from the ...

They load HTTP content even if you accessed it via https; your browser might block this "mixed content" because of security reasons. At least, mine does.

That's why the link without https works: http://potatosemi.com/

And this is the list resulting from assembling it:
[...]
00F004 1 A4 EA 88 D0 waitBaud; Delay 1 bit time
00F008 1 FD
00F009 1 EA NOP
00F00A 1 A4 EA 88 D0 waitBaud; Delay 1 bit time
[...]
Please also note this PR https://github.com/cc65/cc65/pull/2279, which wants to add the expansion of macros in ...

You are right. As I unpacked 2.4.0 over the older 2.3.14, I did not notice that the dir doc/ was removed.

Note that the file doc/fileformat.txt in the archive is still version "V1.2 as of 26jan1998", while http://www.6502.org/users/andre/o65/fileformat.html lists "V1.3 as of 31 mar 2005".

Would the good old GODIL qualify as FPGA in DIP? Unfortunately, as far as I know, it is not for sale anymore.

I had thought about wired-or, too, but I am not sure about the propagation delay.

What a loss!

His "CMOS Cookbook" (1st ed. in German) was one of my first books I had in the 80s when I begin to interest in digital logic families. It is still on the shelf behind me.

@drogon, are you aware that your union and its usage assumes a little endian machine on which this code is running?

Using
a = temp.t16 & 0xFFu;
c = (temp.t16 >> 8) & 0xFFu;
and, even better, getting rid of this union at all would be much more portable.
I hope the compiler will be able to ...

For IEC, even the parallel port of a PC can do the job (that is, if you still have one).
I had written a small program for this many, many years ago (https://spiro.trikaliotis.net/pposc) which I used for OpenCBM debugging. This program must run on plain DOS, no DOS extended, no virtual 8086 mode.

My I answer on this old thread? I even registered here in order to add what I have to say. ;)

I stumbled about the WDTEST macro myself some days ago, and I tried to do my own investigations.

I wrote my findings an guesses on the cbm-hackers mailing list (cf. http://www.softwolves.com/arkiv/cbm ...