+Larry Posted May 7, 2010 Share Posted May 7, 2010 I've been trying to learn more about the XL/XE checksums so I have several questions... According to "Mapping the Atari (revised)" Appendix 12, PEEK(65527) ($FFF7) is the revision number of the OS. (Mine is 2 on this particular XE) PEEK(65528) is the LSB of the checksum. (Mine is 140) PEEK(65529) is the MSB of the checksum. (Mine is 108) Does anyone know of a BASIC or Action! program that calculates the checksum of the OS? Seems like this would be useful but I've never seen one. What bytes in the OS (if any) are excluded from the checksum calculation? This would be laid out pretty clearly in a Basic prog. Thanks, Larry Quote Link to comment Share on other sites More sharing options...
Rybags Posted May 7, 2010 Share Posted May 7, 2010 (edited) Info you need is http://www.atariarchives.org/mapping/appendix12.php XL OS has various checksums for ROM regions $5000-$57FF, $C002-$CFFF, $D800-$DFFF and $E000-$FFF7. The checksum is a simple 16-bit add, so is different to the way SIO does it (8-bit, adding Carry back in each time). BASIC program would be fairly simple, something like: 1000 CHECK=0 1010 FOR A=START TO FINISH 1020 CHECK=CHECK+PEEK(A):NEXT A 1030 H=INT(CHECK/65536):CHECK=CHECK-(H*65536): REM DO AND #$FFFF on checksum Edited May 7, 2010 by Rybags Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted May 7, 2010 Share Posted May 7, 2010 I got these progams from one of the forums, can't remember where..........but back when I was doing a lot of MyIDE OS Eprom burning. chksum&rom.zip good luck! 2 1 Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted May 7, 2010 Share Posted May 7, 2010 Is the cartridge checksum worked out in the same way? I'm concerned as to what will happen with a bank-switched cart when reset is pressed... Quote Link to comment Share on other sites More sharing options...
Rybags Posted May 7, 2010 Share Posted May 7, 2010 Cart checksum isn't stored anywhere in ROM... was only introduced in XL to detect if one is hotswapped. It's only an 8-bit value, and for whatever reason calculated by adding $BFF0-CFEF, adding the carry back into the sum (except for carry from last add) Browse the XL OS around C4C9 for the routine that does it. Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted May 7, 2010 Share Posted May 7, 2010 Cart checksum isn't stored anywhere in ROM... was only introduced in XL to detect if one is hotswapped. It's only an 8-bit value, and for whatever reason calculated by adding $BFF0-CFEF, adding the carry back into the sum (except for carry from last add) Browse the XL OS around C4C9 for the routine that does it. Thanks - I'll do that. Quote Link to comment Share on other sites More sharing options...
+Larry Posted May 7, 2010 Author Share Posted May 7, 2010 Thanks to all, and especially Roy. Perfectly clear Basic programs -- they will go immediately into to my "A-list" utilities! -Larry I got these progams from one of the forums, can't remember where..........but back when I was doing a lot of MyIDE OS Eprom burning. chksum&rom.zip good luck! Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted February 3, 2015 Share Posted February 3, 2015 My Sunrise Z1000b programmer has a checksum function that works beautifully with OS ROMs. Here: https://kickass.so/neowareprogrammer-t7411233.html is a torrent with software for it. It is designed for a Neoware CA15 thin client connected to the Serial port of the Z1000b (or Needham's SA-20), but should be adaptable to many machines. I made this, and have used it many times without a single failure. Hope it helps. Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted February 4, 2015 Share Posted February 4, 2015 Here is the README from the torrent I mentioned above. Note that you need to use a USB flash drive to install it onto your thin client, or you may extract the dd image from the zip file and copy it to your drive any way you like. Welcome to my attempt at an easy solution for older device programmers.Remember about limited writes to flash drives! For that reason,drive D: is set up as a RAMdisk, and C: is locked at boot time.Use D: for temporary storage, then, copy your files using XTreeto/from the Network drive E:.You WILL need to modify the startup files to make it work on your network.The choices in the menu should do it. First, Unprotect the Flash, thenEdit AUTOEXEC.BAT and replace my network info with yours.Do NOT change anything else, Do the same in Net connections.Re-protect Flash, re-boot and test your work.If you are running this on a Neoware CA15, that's it, but if you usedifferent hardware, then you need to select a different Net card driver,probably need to re-optimize QEMM, etc. It can be a very challengingand time consuming process, and definitely beyond the scope of this readme.To use this on a Needham's SA-10 or SA-20, Connect your Programmer tothe COM1: port and run the Needham's software from the menu. Check yourfile pointers, and MAKE SURE to include D:\EPROM\ in the PC Filename.When saving .HEX files, it will be necessary to Edit the resulting file,and remove the first line. In the XTree Editor, use Ctrl-Y.Sunrise Z1000B is a little different, COM1: connected to Port A, tosend a .HEX file to the Programmer, Set up the transfer on theProgrammer, when it asks I/O port A/B, go to XTree, select your .HEXfile, press F9, then press A on the Programmer, then (quickly) selectSend Direct to COM1: in the Menu.Use Procomm to receive .HEX files from the Programmer, pgdn key, ASCIIformat, esc when done.ALWAYS Start the Receiving end first, also, No need to edit .HEX filesas with the Needham's.*** Important*** Remember that files go in D:\EPROM. You *MUST* re-logthe D drive to see the new files.Atari BASIC Ver. C is included in c:\eprom. Use it to test.the J key in XTree will compare two files, it is a VERY useful tool.Good Luck!-Kyle Quote Link to comment Share on other sites More sharing options...
Quantum Mechanic Posted February 7, 2015 Share Posted February 7, 2015 When I was doing a lot of OS ROM tweaking/burning on my 8-bit machines, I found the easiest way to deal with the OS checksum was to just disable the checksum test in the OS code. Quote Link to comment Share on other sites More sharing options...
+JAC! Posted February 7, 2015 Share Posted February 7, 2015 Computing a checksum is easy. Computing an Atari OS checksum is, ... it depends :-). I went through it deeper than originally expected. http://www.wudsn.com/index.php/productions-atari800/tools/atariromchecker 1 Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted July 11, 2018 Share Posted July 11, 2018 Did anyone download that torrent I posted, I hope? If so, please provide a link. I can't seem to find it now... Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted July 11, 2018 Share Posted July 11, 2018 (edited) maybe you can get it back from foreign site... hope it's still in english.... http://www.warezik.eu/archive/t-365948.html or maybe this is better... not sure.. might be usb not 232 https://www.daddytorrents.top/download-NeowareProgrammer-limetorrents_2502560.html or maybe russia.... just make sure to wear protection, the place crawls... i saw kyle22 in two of these choices http://7tor.org/viewtopic.php?t=1905288 Edited July 11, 2018 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted July 11, 2018 Share Posted July 11, 2018 Yeah, I had am image ready made for it, just can't find it now. It's probably on an a hard disk somewhere with pictures of Loretta on it. I SO want that stuff back... \ Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted July 11, 2018 Share Posted July 11, 2018 you posted at same time as my edit came through.... the last one might be it.... Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted July 11, 2018 Share Posted July 11, 2018 Thanks for the links Doc. Hopefully some seeds will show up. Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted July 11, 2018 Share Posted July 11, 2018 Re-Seeding now 3 Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted July 19, 2018 Share Posted July 19, 2018 Initially I showed 0 seeds but sometime between then and now I got it all, and its re-seeding.. Here's the magnet link my client is currently showing to save others from going down the wrong rabbit holes of the Internet. magnet:?xt=urn:btih:136EE376938AAB77442D6A1BEF20979261BF5E02&dn=NeowareProgrammer&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969%2Fannounce&tr=udp%3A%2F%2F9.rarbg.to%3A2710%2Fannounce&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969%2Fannounce&tr=udp%3A%2F%2Ftracker.pirateparty.gr%3A6969%2Fannounce&tr=udp%3A%2F%2Feddie4.nl%3A6969%2Fannounce 1 Quote Link to comment Share on other sites More sharing options...
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