JiffyDOS for the C64/C128
Contents
1. JiffyDOs changes several of the vectors in the 768 779 0300 030B range Q resets them to stock values BASIC add on utilities and other programs also change these vectors to point at themselves A well written program will save the vector it replaces and jump to it when done But not all programs are well written Many programmers will assume the stock values and jump directly to them This will bypass the JiffyDOs com mands I was pleasantly surprised to find that JiffyDOs does not use lo cation 186 BA to determine which drive to access for wedge commands Location 186 holds the current device number ac tually the last device accessed If you just printed something on the printer location 186 will have a value of 4 Many add ons such as Fast Load and the Datel Mark Iv cartridge use loca tion 186 to decide which disk drive to access If you tell the Mark Iv to dis play a disk directory after printing on the printer it vainly tries to show you a directory from device 4 JiffyDOS is smarter It keeps its own active drive number the one you set with It stores it at location 787 0313 This location marked unused on memory maps sits between the USR user routine and the IRQ hardware inter rupt vectors It s only one byte and not in zero page So most programmers don t use it But JiffyDos does and I do JiffyDos also knows the legal disk device numbers I could change between disk drives2. D filename lists a BASIC program to the screen without disturbing memory The listing can be paused by pressing any key The listing can be redirected to a printer with OPEN4 4 CMD4 T filename will display or type sequential files on the screen again without disturbing memory Pressing any key will pause the display CMD will redirect the output to a printer or disk drive You can use T to copy a sequential file to Transactor another disk drive although READY will be appended to the end of the copy CONTROL P will print the current low resolution text screen on your printer sometimes The printer must be device 4 and either a Commodore printer or a good emulation The com mand worked fine in direct mode I hoped to get hard copy of screens from databases and spread sheets But CONTROL P didn t work from inside most pro grams Occasionally one of the public domain Disk Doctors printed but only in upper case graphics mode although the screen was upper lower case NO0 disk id formats a disk in about 20 seconds not as fast as some systems But the documentation claims that all normal error checking is maintained N2 disk id formats both sides of a disk for 1571 drives in 1541 mode This facilitates using both heads when working with a C64 1571 B toggles head bumping on the 1541 With bumping off disk read errors will not cause the obnoxious misaligning rat tle Some software may send i
3. Standard DOS can still read these files too but a bit more slowly then normal One disadvantage of ROM replacement is that you must disas semble your computer and disk drive to make the installation Creative Micro tries to make this as painless as possible They provide six pages of step by step instructions for the comput er and seven pages for the disk drive There are clear draw ings of the various circuit board versions with the location of the ROM to be removed and similar drawings showing the JiffyDOS ROM orientation The instructions are easy to follow and have enough cautions and comments to keep even a novice from running into difficulties I had a minor problem reading a special note for 64C owners It refers to the ROM for the older C64 boards as having 24 pins while the correct ROM for newer 64Cs has 28 pins I have a C64 one of the older boards But the ROM I received has 28 pins The ROM is mounted on a small circuit board The board has 24 pins on it which fit into the Kernal ROM socket on the C64 board The note apparently refers to the number of February 1989 Volume 9 Issue 3 JiffyDOS improves the drive performance on any SEQ REL or USR file Direct block access was also about three times faster in my tests pins on the circuit board not on the ROM chip itself Creative Micro says that a new version of the instructions makes this clear Which brings up the other disadvantage of
4. ROM replacements If you have an older C64 your Kernal ROM may not be in a socket To install JiffyDOS you ll have to unsolder the ROM from the circuit board This is not a job to be taken on lightly If you don t have experience with unsoldering integrated cir cuits you should enlist the aid of a professional Any compe tent computer tech should be able to remove your Kernal ROM and install a low profile socket in its place for a few dollars Many C64s and all 64Cs and C128s have the Kernal ROM socketed rather than soldered in place Most 1541 ROMs are socketed A few rare exceptions have ROMs mounted on piggyback boards Although these can be unsoldered the JiffyDOS ROM and socket mounted on the pig gyback board will sit too high to clear the top cover If you en counter this problem Creative Micro gives you the option of a free special replacement board A wedge and more JiffyDos adds several features besides faster disk access The usual wedge commands are available with the usual syntax filename loads a BASIC program filename will do the same for a machine language file displays a disk directo ry S0 filename will scratch a file etc The gt symbol can be used in place of the JiffyDOs also defines the eight function keys with commonly used wedge commands and RUN and LIST F toggles these definitions on and off filename verifies a file against memory U will un new a BASIC program
5. by POKEing an 8 or 9 to address 787 But any other value was changed to 8 by the next disk ac cess Since the system works with more than two drives I as sume that values of 10 and up would be accepted if those de vices were installed in the system If you use address 787 in your own programs be aware that JiffyDOS may change the value for you That can be a feature To tell from program mode if JiffyDOS is active store 255 at location 787 issue a disk command and see if location 787 contains an 8 Summary JiffyDOS is a good compromise between maximum fast load ing and compatibility You can use any software or hardware Your cartridge Datas sette and user ports are free You can add a disk drive or use part of your system with other non JiffyDOS equipment with February 1989 Volume 9 Issue 3 out difficulty There are no extra wires to bother with and nothing to forget to plug in JiffyDOS supports many non Commodore drives It may be your only choice for a speed up system if you use another manufacturer s drive or mix 1541s and 1571s with the same computer JiffyDOS worked with all the software and add ons I tested in cluding some surprises The Datel Mark Iv cartridge worked normally with JiffyDOS active I loaded a Warp 25 version of Disk Maintenance in seven seconds with the Mark Iv Load ing the standard program with JiffyDOS took 45 seconds Disk Maintenance has its own software fast loader w
6. s Compatibility and RAM The manual says that JiffyDos does not use any extra RAM Random Access Memory in your computer Well almost It s hard to toggle features without using some memory to re member which state the toggle is in If the add on hardware has no RAM it must borrow some from the computer JiffyDos has only ROM So some memory locations are used The designers minimized this impact by using locations that are uncommon to most software routines Locations 674 02A2 and 675 02A3 are used by the stock Kernal to save CIA Complex Interface Adapter control regis ters during Datassette 1 0 Since JiffyDOS doesn t use the Datassette it uses these addresses as toggles Address 674 holds the function key toggle A non zero value turns off the pre defined function keys JiffyDos toggles the value at address 675 between 5 and 133 whenever B is pressed The value is then sent to disk drive address 106 6A This address controls the number of read at Transactor The compatibility ROM is identical to the Kernal ROM 3 This insures full compatibility and upgrades a ROM I or ROM 2 C64 tempts when a disk error is encountered A 5 causes the normal activity complete with head bump A 133 bypasses the bump ing part the high bit is set 133 128 5 This is a tradi tional method of eliminating head bump But a drive reset defeats it So some software may still cause head bumps
7. JiffyDOS for the C64 C128 Look Ma Hardware review by Noel Nyman JiffyDOS is available for C64 C64 C SX64 C128 C128 D and 1541 1541 C 1541 II 1571 1581 FSD MSD Excelerator Excel 2001 Enhancer 2000 C64 series and one drive 49 95 C128 series and one drive 59 95 additional drive ROMs 24 95 all prices plus shipping US dollars Creative Micro Designs P O Box 789 Wilbraham MA 01095 413 525 0023 Specify computer and disk drive models when ordering My first encounter with hardware to speed up my C64 1541 combination was 1541 FLASH It was incredibly fast compared to stock machines Block reads with Disk Doctor were on the screen almost before you could release the RETURN key It also sported an extra cable between the drive and the Datasset te port You could put that plug in upside down I found that out the hard way You could break the wires off the plug found that out the hard way too FLASH permanently replaced the computer and disk drive ROMs Read Only Memories and worked only with the 1541 It was supposed to be compatible with everything But the newest copy protection systems used 1541 ROM codes and wouldn t work with FLASH That was several years ago and I m sure FLASH has improved It and many similar products still require an extra cable be tween the computer and disk drives A corollary of Murphy s Law says that the cable supplied will always be just inches sho
8. hich probably deactivated the JiffyDOS routines Once running Disk Mainte nance however JiffyDOS read the blocks from the disk three times faster than with the Mark Iv alone For ease of use with some helpful features added JiffyDOS is a good value Here at the Transactor offices we have received JiffyDOS for the C128 and 1571 This product works in 64 mode as well as 128 mode The instructions were very clear and well illustrated Installation was simple and the system works well In our case the drive instructions amounted to six pages the 1541 has been through several revisions and therefore re quires seven pages JiffyDOs allows power on ROM switching Crashing or hang ing up is possible response varies with the program Do not switch during a disk access On 1571 and 1581 drives the drives sense whether the com puter is in stock or Jif fyDOS mode and select the correct rou tines automatically JiffyDOS speeds up 1571 and 1581 drives though not as dramatically as it does the 1541 _ Faster than a Speeding Cartridge More Powerful than a Turbo ROM It s Fast It s Compatible It s Complete It s Jiffy Ultra Fast Disk Operating System for the C 64 SX 64 amp C 128 Speeds up all disk operations Load Save Format Scratch Validate access PRG SEQ REL amp USR files up to 15 times faster e Uses no ports memory or extra cabling The JiffyDOS ROMs upgrade your computer and drive s internall
9. lso influence the re sults that you obtain on your system T Speed Comparison Chart C64 SX 64 64 mode Load 202 block PRG file Save 100 block PRG file Read 125 block SEQ or USR file Write 100 block SEQ or USR file Read 64 154 byte REL records Write one 154 byte REL record Read write 16K on command channel ee 154 124 75 84 40 350 125 47 12 24 15 27 14 9 C128 in 128 mode Load 202 block PRG file Baye 100 block PRG file saps Write 100 block SEO or USR file Read 64 154 byte REL records Autoboot 202 block program Read write 16K on command channel Transactor February 1989 Volume 9 Issue 3
10. rt of what s needed to locate your equipment where you want it A product that does not require extra wiring is JiffyDos from Creative Micro Designs The system uses the standard serial bus cable for all data transfers JiffyDOs replaces ROMs in the computer and disk drives I test ed it on a C64 ROM 3 with two 1541 disk drives Both drives were equipped with JiffyDOS ROMs although that s not neces Transactor no cables sary The system will work at normal speed with any addition al drives that are not upgraded Unlike some cartridge based products ROM replacements speed up SAVE and block access as well as LOAD JiffyDos LOADs files about nine times faster than a standard system SAVEs are about three times faster JiffyDos works at this faster speed with all types of files and with block accesses as well Programs such as SuperBase may LOAD rapidly with many other products But they operate at normal slow speed because they rely heavily on sequential or relative files JiffyDOS improves the drive performance on any SEQ REL or USR file Direct block access was also about three times faster in my tests JiffyDOS uses the standard Commodore DOS format to save files It changes the interleave the number of disk sectors skipped between consecutive sectors of a file to six Com modore uses an interleave of ten This makes for faster loads of files SAVEd with JiffyDos when JiffyDOS is used
11. ts own code to the drive which turns the bump back on In that case two B commands are needed to turn bumping off again More on this in a moment Q disables the wedge and function key commands Fast disk access routines are still in place A SYS to an address in ROM will re enable the functions that Q kills Wedge commands can be used in BASIC programs They can be chained several commands on one line v o so test 8 This can be done in program or direct mode Note that the quotes are required and an in the chain will cause the re maining commands to be skipped The wedge commands will accept string variables but only in program mode Numeric variables can be used for some pa rameters such as disk drive numbers in either mode Compatibility and copyrights Creative Micro claims that JiffyDOS is completely compatible with all commercial hardware and software They guarantee it for 30 days from purchase If you find something that won t work you can return JiffyDos for a full refund Obviously a replacement with all these features changes the Kernal ROM code substantially As usual the extensive Datas sette routines are replaced with the new code That alone would make the ROM incompatible with one piece of com mercial hardware the Datassette Some products avoid this problem by providing a board with two sockets one for the new ROM and one for your old Kernal February 1989 Volume 9 Iss
12. ue 3 ROM A switch selects one or the other hence full compatibil ity If something won t work just throw the switch JiffyDOS does this one better The small circuit board with its 24 pins holds only one ROM It does have a toggle switch sol dered to it on about a foot of wire You mount this switch in a hole you drill in the plastic case The installation instructions suggest places where the switch won t be in the way of inter nal workings Switches are connected to the ROMs for disk drives as well The switch selects one of two 8K banks of memory in the ROM One is JiffyDos The other is supposed to be fully com patible with your old computer ROM When I threw the switch and reset the computer I was greeted with the familiar sign on message the exact same message Curious I checked the stock ROM code against the original Kernal ROM Not only are they compatible they re byte for byte identical This makes for a curious situation re garding Commodore s copyright on the ROM code It does ensure that the user has full compatibility It also gives you a ROM upgrade in case you have an older ROM 1 or ROM 2 C64 If you need to disable JiffyDOS on the computer and several disk drives you ll have to throw a switch on each This could be a bother if you have sev eral programs requiring the change You can make it easier by mounting the drive switches on the front panels or under the front bezel on 1571
13. y for maximum speed and compatbiiity Guaranteed 100 compatible with all software and hardware JittyDOS speeds up the loading and internal file access operation of virtually all commercial software e Built in DOS Wedge plus 14 additional commands and convenience features including one key load save scratch directory menu and screen dump Easy do it yourself Installation No electronics experience or special tools re quired Illustrated step by step instructions included Available for C 64 64C SX 64 C 128 amp C 126D JiffyDOS 128 speeds up both 64 and 128 modes and 1541 1541C 1541 4 1571 1581 FSD 1 amp 2 MSD SD 142 Exce 2001 Enhancer 2000 Amtech Swan Indus amp Biuechipdisk drives System includes ROMs for computer and 1 disk drive stock JiffyDOS switching system illustrated installation instructions User s Manual and Money Back Guarantee Pie poing pero A eae Sioto 9 ASE Sa e VISAI 19 COD Che veh 7 Catto efor more infor hon De stor amp UG p Please specity c mputo and drive when sidering Creative Micro Designs Inc P O Box 789 Wilbraham MA 01095 8 50 Industrial Dr Box 646 E Longmeadow MA 01028 ARS Qani anig Phone 413 5 525 0023 a FAX 413 525 0147 ga Speed Comparison The chart below is from the JiffyDos manual and is based on results obtained using ML routines They do not take into account spin up delay 5 sec or direc tory searching time Other factors may a
Download Pdf Manuals
Related Search