Home » Archimedes archive » Micro User » MU 1992-08.adf » ArcFSExtra » Documents/RandomIO
Documents/RandomIO
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » Archimedes archive » Micro User » MU 1992-08.adf » ArcFSExtra |
| Filename: | Documents/RandomIO |
| Read OK: | ✔ |
| File size: | 06B3 bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
Duplicates
There is 1 duplicate copy of this file in the archive:
- Archimedes archive » Micro User » MU 1992-08.adf » ArcFSExtra » Documents/RandomIO
- Archimedes archive » Micro User » MU 1992-09.adf » ArcFSExtra » Documents/RandomIO
File contents
ArcFS 0.50/2.00 Documentation ----------------------------- Random access filing -------------------- Files are decompressed and held in R.M.A. whilst they are open. You should note that when sprite files are loaded they are opened for random access input and therefore there needs to be enough free memory available when the sprites are loaded. This may cause problems when large sprite files are loaded into a 1 Mbyte machine (anyone with an unexpanded A305 - don't bother!) but I cannot really suggest anything short of upgrading to 2 Mbytes (other than making sure that all the possible free memory is available to the R.M.A.). When I bought my 2Mbyte RAM upgrade in Dec. 1989 it cost �150 +VAT. Now it can cost as little as a third of that price and is still falling. I have found it very useful and can recommend it to any users of 1 Mbyte A3000's and A410's who use their computers for more than just arcade games. Other files such as Exec and Obey files are also opened for random access input but these are usually short. A maximum of five files may be open for update with the r/w version (BASIC's OPENUP and OPENOUT) but there is no limit to the number of files open for input only (BASIC's OPENIN). Write access will only be given to an existing file if: It is opened using 'OPENUP' (not 'OPENIN') It has write access and is not locked The archive is not write protected (i.e. has write access and is not locked) Otherwise the file will not be given write access and attempts to write to will give a 'Not open for update' error. To gain read access the file must have read access (!) otherwise a 'Not open for reading' error will be generated if an attempt is made to read from the file.
00000000 41 72 63 46 53 20 30 2e 35 30 2f 32 2e 30 30 20 |ArcFS 0.50/2.00 | 00000010 44 6f 63 75 6d 65 6e 74 61 74 69 6f 6e 0a 2d 2d |Documentation.--| 00000020 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------| 00000030 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 0a 0a 52 61 6e |-----------..Ran| 00000040 64 6f 6d 20 61 63 63 65 73 73 20 66 69 6c 69 6e |dom access filin| 00000050 67 0a 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |g.--------------| 00000060 2d 2d 2d 2d 2d 2d 0a 0a 46 69 6c 65 73 20 61 72 |------..Files ar| 00000070 65 20 64 65 63 6f 6d 70 72 65 73 73 65 64 20 61 |e decompressed a| 00000080 6e 64 20 68 65 6c 64 20 69 6e 20 52 2e 4d 2e 41 |nd held in R.M.A| 00000090 2e 20 77 68 69 6c 73 74 20 74 68 65 79 20 61 72 |. whilst they ar| 000000a0 65 20 6f 70 65 6e 2e 20 59 6f 75 20 20 73 68 6f |e open. You sho| 000000b0 75 6c 64 0a 6e 6f 74 65 20 74 68 61 74 20 77 68 |uld.note that wh| 000000c0 65 6e 20 73 70 72 69 74 65 20 66 69 6c 65 73 20 |en sprite files | 000000d0 61 72 65 20 6c 6f 61 64 65 64 20 74 68 65 79 20 |are loaded they | 000000e0 61 72 65 20 6f 70 65 6e 65 64 20 66 6f 72 20 20 |are opened for | 000000f0 72 61 6e 64 6f 6d 20 61 63 63 65 73 73 0a 69 6e |random access.in| 00000100 70 75 74 20 61 6e 64 20 74 68 65 72 65 66 6f 72 |put and therefor| 00000110 65 20 74 68 65 72 65 20 6e 65 65 64 73 20 74 6f |e there needs to| 00000120 20 62 65 20 65 6e 6f 75 67 68 20 66 72 65 65 20 | be enough free | 00000130 6d 65 6d 6f 72 79 20 20 61 76 61 69 6c 61 62 6c |memory availabl| 00000140 65 20 77 68 65 6e 20 74 68 65 0a 73 70 72 69 74 |e when the.sprit| 00000150 65 73 20 61 72 65 20 6c 6f 61 64 65 64 2e 20 54 |es are loaded. T| 00000160 68 69 73 20 6d 61 79 20 63 61 75 73 65 20 70 72 |his may cause pr| 00000170 6f 62 6c 65 6d 73 20 77 68 65 6e 20 20 6c 61 72 |oblems when lar| 00000180 67 65 20 73 70 72 69 74 65 20 66 69 6c 65 73 20 |ge sprite files | 00000190 61 72 65 0a 6c 6f 61 64 65 64 20 69 6e 74 6f 20 |are.loaded into | 000001a0 61 20 31 20 4d 62 79 74 65 20 6d 61 63 68 69 6e |a 1 Mbyte machin| 000001b0 65 20 28 61 6e 79 6f 6e 65 20 77 69 74 68 20 61 |e (anyone with a| 000001c0 6e 20 20 75 6e 65 78 70 61 6e 64 65 64 20 41 33 |n unexpanded A3| 000001d0 30 35 20 2d 20 64 6f 6e 27 74 0a 62 6f 74 68 65 |05 - don't.bothe| 000001e0 72 21 29 20 62 75 74 20 49 20 63 61 6e 6e 6f 74 |r!) but I cannot| 000001f0 20 72 65 61 6c 6c 79 20 73 75 67 67 65 73 74 20 | really suggest | 00000200 61 6e 79 74 68 69 6e 67 20 20 73 68 6f 72 74 20 |anything short | 00000210 6f 66 20 75 70 67 72 61 64 69 6e 67 20 74 6f 20 |of upgrading to | 00000220 32 0a 4d 62 79 74 65 73 20 28 6f 74 68 65 72 20 |2.Mbytes (other | 00000230 74 68 61 6e 20 6d 61 6b 69 6e 67 20 73 75 72 65 |than making sure| 00000240 20 74 68 61 74 20 61 6c 6c 20 74 68 65 20 20 70 | that all the p| 00000250 6f 73 73 69 62 6c 65 20 66 72 65 65 20 6d 65 6d |ossible free mem| 00000260 6f 72 79 20 69 73 0a 61 76 61 69 6c 61 62 6c 65 |ory is.available| 00000270 20 74 6f 20 74 68 65 20 52 2e 4d 2e 41 2e 29 2e | to the R.M.A.).| 00000280 20 57 68 65 6e 20 49 20 62 6f 75 67 68 74 20 6d | When I bought m| 00000290 79 20 32 4d 62 79 74 65 20 52 41 4d 20 75 70 67 |y 2Mbyte RAM upg| 000002a0 72 61 64 65 20 69 6e 20 44 65 63 2e 20 31 39 38 |rade in Dec. 198| 000002b0 39 0a 69 74 20 63 6f 73 74 20 a3 31 35 30 20 2b |9.it cost .150 +| 000002c0 56 41 54 2e 20 4e 6f 77 20 69 74 20 63 61 6e 20 |VAT. Now it can | 000002d0 63 6f 73 74 20 61 73 20 6c 69 74 74 6c 65 20 61 |cost as little a| 000002e0 73 20 61 20 74 68 69 72 64 20 6f 66 20 74 68 61 |s a third of tha| 000002f0 74 20 70 72 69 63 65 20 61 6e 64 20 69 73 0a 73 |t price and is.s| 00000300 74 69 6c 6c 20 66 61 6c 6c 69 6e 67 2e 20 49 20 |till falling. I | 00000310 68 61 76 65 20 66 6f 75 6e 64 20 69 74 20 76 65 |have found it ve| 00000320 72 79 20 75 73 65 66 75 6c 20 61 6e 64 20 63 61 |ry useful and ca| 00000330 6e 20 72 65 63 6f 6d 6d 65 6e 64 20 69 74 20 74 |n recommend it t| 00000340 6f 20 61 6e 79 20 75 73 65 72 73 0a 6f 66 20 31 |o any users.of 1| 00000350 20 4d 62 79 74 65 20 41 33 30 30 30 27 73 20 61 | Mbyte A3000's a| 00000360 6e 64 20 41 34 31 30 27 73 20 77 68 6f 20 75 73 |nd A410's who us| 00000370 65 20 74 68 65 69 72 20 63 6f 6d 70 75 74 65 72 |e their computer| 00000380 73 20 66 6f 72 20 6d 6f 72 65 20 74 68 61 6e 20 |s for more than | 00000390 6a 75 73 74 0a 61 72 63 61 64 65 20 67 61 6d 65 |just.arcade game| 000003a0 73 2e 20 4f 74 68 65 72 20 66 69 6c 65 73 20 73 |s. Other files s| 000003b0 75 63 68 20 61 73 20 20 45 78 65 63 20 61 6e 64 |uch as Exec and| 000003c0 20 4f 62 65 79 20 66 69 6c 65 73 20 61 72 65 20 | Obey files are | 000003d0 61 6c 73 6f 20 6f 70 65 6e 65 64 20 66 6f 72 0a |also opened for.| 000003e0 72 61 6e 64 6f 6d 20 61 63 63 65 73 73 20 69 6e |random access in| 000003f0 70 75 74 20 62 75 74 20 74 68 65 73 65 20 20 61 |put but these a| 00000400 72 65 20 75 73 75 61 6c 6c 79 20 73 68 6f 72 74 |re usually short| 00000410 2e 0a 41 20 6d 61 78 69 6d 75 6d 20 6f 66 20 66 |..A maximum of f| 00000420 69 76 65 20 66 69 6c 65 73 20 6d 61 79 20 62 65 |ive files may be| 00000430 20 6f 70 65 6e 20 66 6f 72 20 75 70 64 61 74 65 | open for update| 00000440 20 77 69 74 68 20 74 68 65 20 72 2f 77 20 76 65 | with the r/w ve| 00000450 72 73 69 6f 6e 20 28 42 41 53 49 43 27 73 0a 4f |rsion (BASIC's.O| 00000460 50 45 4e 55 50 20 61 6e 64 20 4f 50 45 4e 4f 55 |PENUP and OPENOU| 00000470 54 29 20 62 75 74 20 74 68 65 72 65 20 69 73 20 |T) but there is | 00000480 6e 6f 20 6c 69 6d 69 74 20 74 6f 20 74 68 65 20 |no limit to the | 00000490 6e 75 6d 62 65 72 20 6f 66 20 66 69 6c 65 73 20 |number of files | 000004a0 6f 70 65 6e 20 66 6f 72 0a 69 6e 70 75 74 20 6f |open for.input o| 000004b0 6e 6c 79 20 28 42 41 53 49 43 27 73 20 4f 50 45 |nly (BASIC's OPE| 000004c0 4e 49 4e 29 2e 0a 0a 57 72 69 74 65 20 61 63 63 |NIN)...Write acc| 000004d0 65 73 73 20 77 69 6c 6c 20 6f 6e 6c 79 20 62 65 |ess will only be| 000004e0 20 67 69 76 65 6e 20 74 6f 20 61 6e 20 65 78 69 | given to an exi| 000004f0 73 74 69 6e 67 20 66 69 6c 65 20 69 66 3a 0a 0a |sting file if:..| 00000500 49 74 20 69 73 20 6f 70 65 6e 65 64 20 75 73 69 |It is opened usi| 00000510 6e 67 20 27 4f 50 45 4e 55 50 27 20 28 6e 6f 74 |ng 'OPENUP' (not| 00000520 20 27 4f 50 45 4e 49 4e 27 29 0a 49 74 20 68 61 | 'OPENIN').It ha| 00000530 73 20 77 72 69 74 65 20 61 63 63 65 73 73 20 61 |s write access a| 00000540 6e 64 20 69 73 20 6e 6f 74 20 6c 6f 63 6b 65 64 |nd is not locked| 00000550 0a 54 68 65 20 61 72 63 68 69 76 65 20 69 73 20 |.The archive is | 00000560 6e 6f 74 20 77 72 69 74 65 20 70 72 6f 74 65 63 |not write protec| 00000570 74 65 64 20 28 69 2e 65 2e 20 68 61 73 20 77 72 |ted (i.e. has wr| 00000580 69 74 65 20 61 63 63 65 73 73 20 61 6e 64 20 69 |ite access and i| 00000590 73 20 6e 6f 74 20 6c 6f 63 6b 65 64 29 0a 0a 4f |s not locked)..O| 000005a0 74 68 65 72 77 69 73 65 20 74 68 65 20 66 69 6c |therwise the fil| 000005b0 65 20 77 69 6c 6c 20 6e 6f 74 20 62 65 20 67 69 |e will not be gi| 000005c0 76 65 6e 20 77 72 69 74 65 20 61 63 63 65 73 73 |ven write access| 000005d0 20 61 6e 64 20 61 74 74 65 6d 70 74 73 20 74 6f | and attempts to| 000005e0 20 77 72 69 74 65 20 74 6f 0a 77 69 6c 6c 20 67 | write to.will g| 000005f0 69 76 65 20 61 20 27 4e 6f 74 20 6f 70 65 6e 20 |ive a 'Not open | 00000600 66 6f 72 20 75 70 64 61 74 65 27 20 65 72 72 6f |for update' erro| 00000610 72 2e 0a 0a 54 6f 20 67 61 69 6e 20 72 65 61 64 |r...To gain read| 00000620 20 61 63 63 65 73 73 20 74 68 65 20 66 69 6c 65 | access the file| 00000630 20 6d 75 73 74 20 68 61 76 65 20 72 65 61 64 20 | must have read | 00000640 61 63 63 65 73 73 20 28 21 29 20 6f 74 68 65 72 |access (!) other| 00000650 77 69 73 65 20 61 20 27 4e 6f 74 20 6f 70 65 6e |wise a 'Not open| 00000660 0a 66 6f 72 20 72 65 61 64 69 6e 67 27 20 65 72 |.for reading' er| 00000670 72 6f 72 20 77 69 6c 6c 20 62 65 20 67 65 6e 65 |ror will be gene| 00000680 72 61 74 65 64 20 69 66 20 61 6e 20 61 74 74 65 |rated if an atte| 00000690 6d 70 74 20 69 73 20 6d 61 64 65 20 74 6f 20 72 |mpt is made to r| 000006a0 65 61 64 20 66 72 6f 6d 20 74 68 65 0a 66 69 6c |ead from the.fil| 000006b0 65 2e 0a |e..| 000006b3
.