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101090 discussions

by peacock＠simconv.com

<[Everyone predates the PC, except for me...] <I'm from 1978, same year VAX was invented. <The PC is from 76, right? I'm not too far off... <------- Hmmm, then I predate the S/360, the Bendix G-1, maybe even the IBM 650 (did it come out before 1955?). Jack Peacock (even old enough to remember the Univac NBC/Huntley & Brinkley used for 1960 election night)

28 years, 2 months

Atari hard drives?

by allisonp＠world.std.com

<As I recall, the proper name for the Shugart 506 interface became a <proto-standard called SASI, and is a direct ancestor to SCSI. Though <it's a bit hard to recognize the grandparent in the children's faces. No not correct. SASI did become SCSI but SASI is not ST506. ST506 is a raw device interface that is actually a graduate of the floppy interface for 5.25 floppies and closer to that. SASI/SCSI is a higher level parallel bus with arbitration and other features. the biggest difference is that ST506 assumes no intelligence in the drive and SCSI/SASI assumes some intelligence at the slave. SASI Shugart Associates System interconnect The offered that as an interface from the sa4000 drives to a interconnect bus. Others that offered similar boards were Xybec Western Digital and Adaptec. Ampro and others would formalize SASI to SCSI. SCSI Small computer System interconect Used to interconnect intelligent DISKs, TAPES, and CDROMS mostly. It can be used to interconnect systems and offers high data rates. ST506 the raw device (drive) interconnect used initially by Shugart for hard disks and was adopted by others. The basic interface is serial data and the disks data rate on seperate connector using rs422 balanced lines. Control signals like step, direction, head select were on another cable that is bussed liek those for floppies. It's limits were up to 8 heads (later 16) and 5MbS data rate. EDSI was an outgrowth of this. Allison

28 years, 2 months

Atari hard drives?

by allisonp＠world.std.com

<Of course, I was just using the vernacular... (About like "CMOS setup" - <you didn't make any comments about that one though. :-)) But I didn't <remember that it was called ST506. Sounds like a Seagate part number. <Was it a PC hard drive, or even earlier? The ST506 was an early 5mb full height 5.25" hard disk from Shugart (later to become seagate). I still have a few. I predates the PC! The first PCs to have a hard disk used either the ST506 (5m) ST412 (10mb) or the Tandon t100 10mb all of which had a similar st506 drive level interface. <> You're probably thinking of the servo bursts - the signals that keep th <> heads on a track. Some drives did use a particular side of one of the <> platters for these. Other drives 'embedded' them in the sector headers <> the data platters. The latter is not common on ST506 interfaced drives, <> but is common on SCSI/IDE drives < <Hmmm, interesting. So low-level formatting doesn't rewrite these? <That would imply that the servo bursts are not involved in determining <sectors at all. I used to use an RLL card with a couple of formerly <MFM drives, and it made more sectors per track, so I thought the <wasted platter had something to do with that. Servo bursts are written at the factory and if lost the drive is junk as there is no way to reconstitue them. Their primary function is to get the head correctly centered on the cylinder regardless of temperature, vibrations and mechanical wear. MFM vs RLL... The media has a capacity to store a certain number of magnetic transistions per linear inch. This is a design number and unchangeable. What can change is the interpretation of those. RLL uses fewer magnetic transistions to encode data and it's clocking information needed to recover the data later. RLL in effect is data compression. <> Are you sure: While almost all clone controllers have a formatter routi <> at C800:5, < <Yep, that's the one. < <> I couldn't find it in the original IBM XT hard disk BIOS. Some of the controllers didn't have rom and depended on a floppy loaded formatter or floppy loaded driver routine. On one of my floppies I have HDINIT that was used for that purpose. Allison

28 years, 2 months

Final Xerox Star demo

by IVIE＠cc.usu.edu

>What are these bad things? I certainly want to know since I live >near it! > >If you want a description, it's fairly small (in terms of total info), >with a 2-story walk-through PC (when will they get that not every >computer in the world uses intel processors?), To make room for the two-story walk-through PC, they had to get rid of the neato walk-through SAGE exhibit, among others. Basically, they went from a museum a techno-geek could enjoy to something which appeals to the public at large. Roger Ivie ivie(a)cc.usu.edu

28 years, 2 months

Final Xerox Star demo

by maxeskin＠hotmail.com

What are these bad things? I certainly want to know since I live near it! If you want a description, it's fairly small (in terms of total info), with a 2-story walk-through PC (when will they get that not every computer in the world uses intel processors?), a history exhibit, a robotics exhibit, and an "internet exhibit" with stuff like how the information superhighway has transformed the technology paradigm for the new millenium. THe history one is the only mildly interesting one with lots of old machines (S/360, PDP-8, Altair, Apple I, etc.), but a bit small. The machines used in other sections are certainly worth museum appearance. Weird DEC and Apple stuff is all over the place, used for multimedia, but cool in themselves. > >I've certainly heard bad things about the BCM - how true they are I don't >know, since I've never been. > >-tony > > ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

28 years, 2 months

Imsai before 76

by allisonp＠world.std.com

<Almost let an error slip by there, the IMSAI dates to the end of 1975, <November I think, the first ad was in the December 75 issue of Popular <Electronics, along with the Processor Tech VDM-1 video board. We had <one running in the lab by Xmas 75, the short motherboard (12 slot, IMSAI <dropped it early in 76), 8080 CPU and 4K static ram (1K installed), all <for only $429 in kit form. Which is why I said "more like 76". actually I have the Jan 1975 PE with the Altair on the fron which predated the IMSAI. That summer IMSAI announced the IMSAI. FYI by December 76 I would have over 11 months of operational experience with my altair... and wishing I'd gotten a SOL or IMSAI! Speaking of IMSAI I have a IMP-48 (8035 cpu) which was also made by IMSAI as a SBC for control apps and low cost computing. I'm seriously looking for a manual. I've had this board since 81 sans book (It works and I can run it, even preserved the eprom!). The dates on the parts suggest late 78 manufacture. Allison

28 years, 2 months

Imsai before 76

by peacock＠simconv.com

Almost let an error slip by there, the IMSAI dates to the end of 1975, November I think, the first ad was in the December 75 issue of Popular Electronics, along with the Processor Tech VDM-1 video board. We had one running in the lab by Xmas 75, the short motherboard (12 slot, IMSAI dropped it early in 76), 8080 CPU and 4K static ram (1K installed), all for only $429 in kit form. Jack

28 years, 2 months

Atari hard drives?

by allisonp＠world.std.com

<[Everyone predates the PC, except for me...] <I'm from 1978, same year VAX was invented. <The PC is from 76, right? I'm not too far off... <------- Kids.... The PC as in IBM PC was more like 1981... 76 was more like imsai. Allison

28 years, 2 months

Atari hard drives?

by allisonp＠world.std.com

<> I predates the PC! I do I do I do, I do. So does the ST506 interface! Allison

28 years, 2 months

Clueless Museums (was: Final Xerox Star demo)

by icyblackhand＠hotmail.com

do any of you have a Lisa, if so, I'll pay $100 or less. Thanks Mike

28 years, 2 months

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