sansom@trwrb.UUCP (01/29/87)
In article <1112@husc6.UUCP> grunau@husc4.UUCP (justin grunau) writes: > >...they [Byte] make a fair point of stressing that the ST disk ports are about >the fastest around. If you look at the right specs, this seems to be true -- >for instance, Byte lists the top speed of data transmission of the DMA port >at about twice the top speed of the Mac Plus's SCSI port (I forget the >figures). Furthermore, one of the ST articles actually says that most hard >disks for the 512K Mac transmit at a speed barely above the ST's FLOPPY >ports, and that (this is the crucial item) the Mac's (serial) floppy ports >transmit at only a bare fraction of the blindin speed of the ST's (parallel) >floppy ports. > >Now, I should say that this was one of the original pieces of information >that attracted me to the ST... > >Now, however, I am really beginning to wonder. Outside of Magic Sac usage, >I hardly ever need to use floppy accesses since I have a HD. But floppy >accesses do seem to be horrifically slow -- even slower than a PC or XT, >and certainly no great shakes above a Mac or Amiga, if at all above. > >P.S.: I have also heard the opposite about floppy accesses: one dealer >told me that since the ST uses a Western Digital controller, it has to >store all the pointers in the FATs in Intel format -- low-byte first -- >which means the 68000 has to switch them around to read them; this sounds >fairly ridiculous to me, but has been sounding less so as time has gone >on. I'm certainly no expert on floppy disk controllers, but I don't thing the WD controller is the problem. The problem lies with GEMDOS, and with Atari's desire to have a disk format with a definite shade of big blue. For a clearer picture on the ST's potential floppy disk speed, I suggest you try any of the so-called "fast-formatters" which have made the rounds on the net, and are available on many BBs. In fact, if you couple the fast format with no write verification, you finally approach the ST's theoretical maximum disk transfer speed: about 23K/sec. (I wrote a simple program which turns write verify off - it's called veroff and is available upon request, along with veron - a program which turns write verify back on). I have had write verify off for almost a year now, and have not had a single bad disk write because of it. Since Atari is currently re-writing GEMDOS, I won't harp too much about its (GEMDOS's) sorry present state. I will point out, however, that if you use a good compiler (I'm using Mark Williams C), you will notice a marked improvement in floppy disk access, even on disks which have _not_ been "fast-formatted". This clearly indicates that the problem is in the ST's software (TOS/GEMDOS) and _not_ with its hardware, which, I believe, is the fastest in terms of data throughput _potential_ of any micro computer on the market today. -Rich -- __________ ______ ____ _____ ___ /_________//___ ||__|/____|/__/ Richard E. Sansom ___ ____/ / ____________ TRW Electronics & Defense Sector / / / /\ < | /| / One Space Park Drive, R3/1028 / / / / \ \ | / | / Redondo Beach, CA 90278 /__/ /__/ \__\|__/ |__/ ...{decvax,ucbvax,ihnp4}!trwrb!sansom