Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!cmcl2!rutgers!cbmvax!fred From: fred@cbmvax.UUCP (Fred Bowen) Newsgroups: comp.sys.cbm Subject: Re: 1581 - Review & Questions Message-ID: <2314@cbmvax.UUCP> Date: Fri, 11-Sep-87 12:10:40 EDT Article-I.D.: cbmvax.2314 Posted: Fri Sep 11 12:10:40 1987 Date-Received: Sat, 12-Sep-87 19:27:17 EDT References: <14031@amdahl.amdahl.com> Organization: Commodore Technology, West Chester, PA Lines: 86 Keywords: 1581 3.5 inch disk drive commodore c64 dwl10@amdahl.amdahl.com (Dave Lowrey) reviews the CBM 1581 disk drive: > ... It uses "Any good quality 3.5 inch > double sided diskettes"(quote). I bought a box of Memorex single > sided quad density disks (the only type in the store) and those > work, but I plan on buying true double sided disks in the future. Gads. DS/DD soft sector (135 TPI). I fear a lot of problems I hear about (which I cannot duplicate, natch) are caused by things like this. Expect problems if you do this. For some reason quite a few 1541 folks, used to 160K on 5.25" media, don't understand what it takes to put >800K on 3.5" media. > - The biggest drawback to the drive is loosing the fastload ability. So, > I will use the drive for data storage, but not many programs. > - I would also like to see a fast copy program. I calculate a full > disk backup time of 45-60 mins (not including floppy disk swaps!). Please note, this is 'slow' protocol on a c64. You really should try loading a hugh program on a c128/1581. Nice. > Questions: (Listen up Commodore :-) ) > 1. Can burst mode be used on the 64? If so, is there a "fast" serial bus > driver avaliable? Nope- requires some hardware mods. But I'm sure someone will come up with a hardware thingy to accomplish this before much longer. A fast serial add-on cartridge or some such. > 2. The burst mode source file on my demo disk is trashed. I tried to > print it, and after 5 or 6 pages, the file is garbage. Is it just my > disk, or are all of them that way? If it is just my disk, can I get > a new one? If they are all that way, can I get ahold of a good copy? > 3. There is a program on the disk called zapload.64. It includes a > fast loader that works with all CBM drives. Can I get ahold of the > source to this program? (I know, get the ol' disassembler out, right?) Your disk is probably bad- if you bought the drive from a dealer (as opposed to Toys R something) you could probably exchange it. That or find a friend. The source for the Burst routines, ZAPLOADER, etc. are also gonna appear on the DEVpak disk collection (mostly for c128 folks). > 4. The drive has the capability of automatically loading a file > into one of it's buffers, and executing that program upon > drive initialization. This is documented in the 1581 manual. I > know that this feature was also on the 1541, but undocumented. > My question is... what the heck good is it? What would you > use it for? I am making the rash assumption that it is there for > a purpose. Yup- the autobooter is similar to the good old utility file loader, it just loads & runs a specific file into DOS RAM whenever the drive is initialized. It is used, for example, by c128 CP/M boots (to download a different logical sector map). It is useful. > 5. Is "save with replace" safe to use with the 1581? Yup. But I ain't no fool- I still scratch n' save. > 6. Are there any known bugs with the drive? 2 very minor ones that I know of so far- following some writes immediately (less than 250ms) with a UJ (soft reset) to the command channel will cause the drive not to dump the 'dirty' track cache to disk before resetting. The other is a BURST command will cause any direct access channels (#) to disappear (who mixes BURST stuff with # stuff anyway? This is easily worked around anyhow). > Final Words: > I bought this drive for it's storage capacity. The faster sequential/ > relative file access is a plus also. The drive seems to meet all of > my expectations on those points. I sorely miss the fastload capabilities, > but I expected that when I bought the drive. The drive delivers what > it promises, and I would recomend it to anyone needing a large amount > of storage capacity. Thanks, Dave. Transactor has a review this month which basically says the same things as you did. -- -- Fred Bowen uucp: {ihnp4|rutgers|caip}!cbmvax!fred arpa: beats me tele: 215 431-9100 Commodore Electronics, Ltd., 1200 Wilson Drive, West Chester, PA, 19380