╨CM:SDA.PC ╨LM2:RM78:LS6:PP66:PG60 ╨HD3:-<>-,сELF дISSOLVING аRCHIVES,ґ(ц)Ґ1987 - аMPERE мETAL ╨FT2:,,18 йAN 1987 ╨AI+4:JU1 иF YOU'RE READING THIS TEXT FILE, THEN YOU'VE PROBABLY ALREADY GONE THROUGH THE PROCESS OF DISSOLVING THE ARCHIVE THAT WAS USED TO DISTRIBUTE IT. пRETTY EASY HUH? вELL, THATS WHAT SELF-DISSOLVING ARCHIVES (сдARC'S) ARE ALL ABOUT. иT TAKES THE PAIN (OR CONFUSION) OUT OF DISSOLVING ARCHIVES. нOT ONLY ARE сдARC'S EASY TO USE, BUT SINCE THE ARCHIVES CREATED ARE SELF DISSOLVING, IT IS NO LONGER NESSESSARY FOR PEOPLE RECIEVING SUCH FILES TO HAVE арц INSTALLED AND RUNNING BEFORE THEY CAN DISSOLVE THEM. аLL YOU HAVE TO DO IS лоад AND рун AN сдARC. тHIS IS PROBABLY WHAT MOST PEOPLE DO TO DOWNLOADED PROGRAMS ANYWAY, SO INSTRUCTIONS ARE NOT EVEN NESSESSARY. фOR THOSE OF YOU THAT HAVE ONLY A SINGLE 1541 OR 1571, YOU'LL APPRECIATE THE CONVENIENCE OF JUST лоадING THE сдARC INTO рам, SWITCHING DISKS, AND DEPOSITING THE UN-арцED FILES ON A FRESH DISK. сдARC'S ARE ALSO VERY EASY TO CREATE. аLL YOU HAVE TO DO IS ATTACH THE SHORT 4 BLOCK сда PROGRAM TO THE BEGINNING OF THE ARCHIVE AS OUTLINED BELOW. бUT, CONVENIENCE HAS A PRICE. иN ORDER TO KEEP THE сда PROGRAM AS SHORT AS POSSIBLE, WE'VE MADE A FEW SIMPLIFYING ASSUMPTIONS ABOUT THE ARCHIVES THEY ARE TO DISSOLVE. аFTER ALL, ONE OF THE NICE THINGS ABOUT арц IS THAT IT SAVES YOU DISK SPACE AND UP/DOWNLOAD TIME. иF THE сда HEADER WERE TOO LARGE, WE'D LOSE THAT ADVANTAGE. тHE LIMITATIONS IMPOSED BY THESE ASSUMPTIONS ARE AS FOLLOWS: ╨LM10:AI-3 1) тHE сдARC MUST BE CREATED USING AN арц PROGRAM NUMBERED 2.XX тHAT IS, IT MUST BE A VERSION 2 ARCHIVE. 2) тHE сдARC ═MUST нот CONTAIN ANY CRUNCHED FILES. иT MAY ═CONTAIN ANY COMBINATION OF STORED,PACKED SQUEEZED, OR SQUASHED FILES. цRUNCHED FILES REQUIRE ABOUT 28к OF рам AS WORKSPACE, AND THIS WOULD IMPOSE TOO MUCH OF A RESTRICTION ON THE MAXIMUM SIZE OF AN сдARC. иT WOULD ALSO DOUBLE (OR MORE) THE SIZE OF THE сда HEADER. 3) тHE сдARC MUST NOT CONTAIN ANY релATIVE FILES. 4) сда IS MACHINE SENSITIVE. тHE 64 VERSION WON'T WORK IN 128 MODE ON THE 128, AND THE пет VERSION ONLY WORKS ON THE пет AND SO ON. иNCIDENTALLY, THE пет VERSION IS FOR басиц 4.0 ONLY. 5) ыOU═HAVE TO WATCH OUT HOW BIG THE сдARC IS. иF YOU TRY TO LOAD A PROGRAM BIGGER THAN ABOUT 200 BLOCKS INTO THE 64, YOU'LL WIPE OUT THE MEMORY MAPPED и/о AND CRASH THE 64. сдARC'S CAN BE LARGER THAN 200 BLOCKS ON THE ц-64. тHE MAXIMUM SIZE IS ABOUT 243 DISK BLOCKS, ($0801-$ф9фф) BUT YOU WILL HAVE TO WRITE YOUR OWN BOOT PROGRAM SO THAT IT GETS LOADED INTO ╪рамЎ PROPERLY. сEE THE NOTES BELOW FOR SIZE RESTRICTIONS FOR THE VARIOUS VERSIONS OF сда. ╨LM2:AI+1 ╨FP цREATION OF сдARC'S IS QUITE SIMPLE. фIRST, SELECT THE CORRECT VERSION OF THE сда HEADER PROGRAM. иF YOU'RE арцING 64 STUFF, USE THE 64 VERSION; FOR пет STUFF, USE THE пет VERSION. ыOU'LL NEED TO MAKE A COPY OF THE сда PROGRAM, BECAUSE IT WILL BE 'USED UP' BY THE сд-ARCHIVE. нEXT RENAME THE COPY OF сда TO THE NAME OF THE ARCHIVE YOU WANT TO CREATE. тHE NAME YOU CHOOSE WILL HAVE TO END WITH THE FILENAME EXTENSION '.ARC'. нEXT USE арц 2.30 TO APPEND TO THE сда PROGRAM USING арц/аз нEXT, RENAME THE сда TO WHATEVER YOU FEEL LIKE. иTS NOT REALLY AN ARCHIVE, SO AVOID THE '.ARC' FILENAME EXTENSION. фINALLY, лоад AND рун IT, AND MAKE SURE IT WORKS BEFORE UPLOADING IT TO A BUNCH OF BULLETIN BOARDS. мAKE SURE YOU DON'T NEGLECT THIS STEP! ыOU NEVER KNOW WHAT MIGHT GO WRONG. а SAMPLE SESSION, WITH арц ACTIVE, MIGHT GO SOMETHING LIKE THIS. вE'LL ASSUME ALL THE NEEDED FILES ARE ON DRIVE A: >C0:NEWFILE.ARC=0:SDA230.64 (MAKE A COPY) ARC/AZ NEWFILE WHATEVER YOU WANT IN IT (MAKE THE ARCHIVE) REN NEWFILE.ARC NEWFILE.SDA (RENAME IT) DLOAD"NEWFILE.SDA" (CHECK IT OUT) RUN аN ALTERNATE METHOD WOULD BE TO FIRST═CREATE THE ARCHIVE USING арц/цз, AND THEN USE дос TO APPEND THE ARCHIVE TO THE сда PROGRAM. вHEN YOU рун AN сдARC, IT ═ASSUMES THAT THE ARCHIVE FOLLOWS IMMEDIATELY AFTER THE сда PROGRAM. мAKE SURE THAT YOU AVOID USING ьмодем TO TRANSFER THE сда PROGRAM (IN UN-арцED FORM) BECAUSE THIS WILL CHANGE ITS FILE SIZE AND IT WILL THINK THAT THE ьмодем PADDING IS THE FIRST ARCHIVE ENTRY, AND WILL ABORT SINCE THE HEADER WILL NO DOUBT BE INVALID. тHE VERY FIRST FILE IN THE сдARCHIVE IS NOT EXTRACTED TO DISK, BUT IS TYPED TO THE SCREEN INSTEAD. (и GET A LITTLE NERVOUS WHEN A PROGRAM STARTS RIGHT OFF WRITING TO DISK WITHOUT ANY EXPLANATION.) тHIS FIRST FILE CAN, OF COURSE BE SQUEEZED OR SQUASHED, AND SHOULD CONTAIN INSTRUCTIONS FOR THE USER, COPYRIGHT NOTICES OR WHATEVER YOU THINK IS APPROPRIATE. аFTER DISPLAYING THIS FIRST FILE, сда WAITS FOR THE USER TO HIT A KEY. иF THE KEY IS THE═рун/стоп KEY,═THEN сда JUST GOES TO THE реады PROMPT AND WON'T EXTRACT THE сдARCHIVE. иF═ANY OTHER KEY IS PRESSED, IT GOES AHEAD AND EXTRACTS THE REMAINING FILES TO THE DISK IN DRIVE 0 OF UNIT 8. аS THE FILE IS EXTRACTED, YOU WILL SEE THE NAMES OF THE FILES BEING CREATED DISPLAYED ONE AT A TIME. иF, AFTER EXTRACTION, THE CHECKSUM IS OK сда PRINTS "OK" AFTER THE FILENAME. иF THERE IS A CHECKSUM ERROR, сда PRINTS A QUESTION MARK. (?) ╨FP сIZE RESTRICTIONS: $0200-$0230 IS USED BY сда. (аLL VERSIONS) $0100-$0116 IS USED BY сда. (аLL VERSIONS) $фа00-$фефф IS USED BY сда IN THE ц=64 AND ц=128 VERSIONS. $7б00-$7ффф IS USED BY сда IN THE пет VERSION. $0401-$07ф6 сда HEADER IN THE пет. мAX SIZE OF AN сдARCHIVE = 119 BLOCKS. $0801-$0бф6 сда HEADER IN THE 64. '' '' '' 201 '' $1ц01-$1фф6 сда HEADER IN THE 128. '' '' '' 223 '' тHIS MEANS THAT IN THE пет, YOUR сдARCHIVE CAN BE AS BIG AS $7афф-$0401, OR A MAXIMUM OF 119 BLOCKS WHEN STORED ON DISK. иN THE 64, IT CAN BE $д000-$0801 OR ABOUT 201 BLOCKS ON DISK. иF YOU WANT TO CONSTRUCT YOUR OWN боот PROGRAM, THEN IT COULD BE AS LARGE AS $фа00-$0801, OR ABOUT 243 DISK BLOCKS. иN THE ц-128 IT CAN BE $фа00-$1ц00, OR ABOUT 223 цбм DISK BLOCKS. нOTE THAT WE'VE PADDED THE LENGTH OF THE сда HEADER TO AN EXACT MULTIPLE OF 254 BYTES. тHIS WAY IT WILL TAKE UP EXACTLY FOUR BLOCKS ON DISK. иF, FOR SOME REASON YOU WISH TO CONVERT IT TO A REGULAR ARCHIVE, THEN ALL YOU HAVE TO DO IS BOOT UP YOUR FAVORITE DISK DOCTOR AND CHANGE THE (TRACK,SECTOR) POINTER TO THE FIRST BLOCK IN THE FILE SO THAT IT POINTS TO THE FIFTH BLOCK IN THE FILE, AND THE JOB IS DONE.