RE: Compaq Portable 286 and Portable III - IDE drives?

I'm pretty sure the Portable III used a Conner IDE disk drive, see http://chmss.wikifoundry.com/page/Compaq%2FConner+CP341+IDE%2FATA+Drive probably the CP344 but maybe the CP341 (there is some inconsistency in the literature) However that was the first public IDE drive so it is not at all clear

Chip in first Apple AirPort WiFi

Anyone know which Lucent semiconductor device or devices were used in the first Apple AirPort, the Lucent board was " Lucent WaveLAN Silver PC Card" but I'd like to know the devices used. Tom

RE: The Name of the disk (Was: Disk imaging with IMD - question

Me too - great rant. Thanks Tom -Original Message- From: Mark J. Blair [mailto:n...@nf6x.net] Sent: Thursday, August 10, 2017 9:56 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: The Name of the disk (Was: Disk imaging with IMD - question > On Aug 9, 2017, at

RE: 5.24-inch FDD invention [was RE: Diskette size]

Jobs had nothing to do with the invention of the 5.25" FDD: The original impetus for a smaller less expensive FD came from Lanier via Jimmy Adkisson in mid 1975 By early 1976 the Shugart Associate's engineers were working on a medium and device based upon the size of the cassette tape drive

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

rature uses. Tom -Original Message- From: Chuck Guzis [mailto:ccl...@sydex.com] Sent: Sunday, October 01, 2017 12:59 PM To: Tom Gardner via cctalk Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC] On 10/01/2017 12:46 PM, Tom Gardner via cctalk w

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

ide hard drive and floppy disk controllers" Will On October 2, 2017 at 8:04 PM Tom Gardner via cctalk <cctalk@classiccmp.org> wrote: Unfortunately there is no documentation to support Pete's recollection - if there is any I would like to see it. For example: · WD's Fall

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

s I’d love to see them Tom -Original Message- From: Pete Turnbull [mailto:p...@dunnington.plus.com] Sent: Monday, October 02, 2017 8:29 AM To: Tom Gardner via cctalk Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC] On 01/10/2017

The origin of SCSI [WAS:RE: The origin of the phrases ATA and IDE ]

I suspect this might start another discussion, but as I understand it Apple had little to do with the evolution of SASI into SCSI. Shugart Associates published SASI in 1981 and took it to ANSI in 1982 where they renamed it SCSI to avoid using a vendors name. To quote from the draft SCSI 1

RE: Reviving ancient MFM drives (was Re: formatting MFM drives on a IBM PC)

Old 10 and 20 MB MFM drives are most likely open loop positioning systems which are highly vulnerable to off track due to thermal changes and stiction. They also could have flying height problems due to contamination on the slider. These failure modes can manifest themselves a slow soft

RE: formatting MFM drives on a IBM PC

I think Chuck has it backwards, AT Attachment as defined by the ANSI committee publically predates IDE. Although IDE was used internally at WD it did not surface publically until well after the ANSI committee adopted AT Attachment, abbreviated ATA. The AT in AT Attachment or ATA has never stood

The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

ot leap to an obvious but incorrect conclusion. Tom -Original Message- From: Chuck Guzis [mailto:ccl...@sydex.com] Sent: Saturday, September 30, 2017 5:58 PM To: Tom Gardner via cctalk Subject: Re: formatting MFM drives on a IBM PC On 09/30/2017 04:12 PM, Tom Gardner via cctalk wrot

RE: IBM 3330 Drive

FWIW Paul Alan's Living Computer Museum has (or had) working PDP10's using DEC’s RP06's which are very similar to a 3330-11 (they are Memorex 677's with a bolt on DEC controller). They will not mount a

RE: IBM 3330 Drive

st holding it out exposed like that. Let's hope he put it back in the canister very carefully and quickly. Can anybody guess the correct model of disk pack from this single picture and angle? (Sorry, it's all I have to go on right now). Thanks! -AJ On Mon, Aug 28, 2017 at 11:16 AM, Tom G

9/14 Panel discussion - Dialog: The Beginning of Online Search

The IEEE Silicon Valley Technical History Committee is sponsoring a panel discussion, "Dialog: The Beginning of Online Search" featuring Roger Summit the founder of Dialog along with ex-employees and users. Register at: https://scvhist20170914.eventbrite.com/ More information at:

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

WD acquired the Tandon drive business in 1988 so it was both a drive maker and a chip supplier to other drive makers. WD used the term "Integrated Drive Electronics" internally as early as June 23, 1985 on proprietary business plans (I have copies) but the target "Intelligent Drive" interfaces

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM

-Original Message- From: Alan Perry [mailto:ape...@snowmoose.com] Sent: Tuesday, October 03, 2017 12:27 PM To: cctalk@classiccmp.org Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM I am continuing to investigate, but I think that IDE came first. I have

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

...@dunnington.plus.com] Sent: Tuesday, October 03, 2017 10:56 AM To: cctalk@classiccmp.org Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC] On 03/10/2017 01:04, Tom Gardner via cctalk wrote: > Unfortunately there is no documentation to support Pete's recollect

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

via cctalk Subject: Re: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC] Tom Gardner via cctalk < <mailto:cctalk@classiccmp.org> cctalk@classiccmp.org> writes: > But again if anyone has any documents dating IDE in the 1980s I d love >

RE: The origin of the phrases ATA and IDE [WAS:RE: formatting MFM drives on a IBM PC]

After reading all the input I updated the article at: http://chmss.wikifoundry.com/page/Compaq%2FConner+CP341+IDE%2FATA+Drive where you will now find a picture of what is likely the first ATA drive, called “fixed disk drive with embedded controller” by Compaq J You might note that the

RE: Idle question: Color of tape coatings

Hi: The following answer comes from a retired IBM tape technologist: The color of the coatings on a tape are dominated by the magnetic pigment (or the carbon used in back coats..which is black)..the earliest iron oxide coatings were based on the conversion of alpha-iron oxide which is a pale

RE: Looking for AMP / TE coaxial connectors - Memorex 651 drive

It is from the AMP M series connector family used in the data cable for the IBM 2311/2314 and PCM equivalents including double density like the ISS 715 (RP03?). So some of the parts strippers should have lots. Using coax at the FDD data rate was overkill so unless you want to preserve the

RE: eBay: MEMOREX 3693-2 & 3690-2 Disc Drive Mainframe IBM 3370-2 VINTAGE

AFAIK these are rebadged Japanese (probably NPL) controller and drives compatible with the IBM 3370 series. The 3693-2 is a controller bundled with two drives while the 3690-2 is just two drives, other than skins just like the two in the 3693. They are FBA as opposed to CKD They likely

RE: Looking for AMP / TE coaxial connectors - Memorex 651 drive

+01:00 Tom Gardner via cctalk <cctalk@classiccmp.org>: It is from the AMP M series connector family used in the data cable for the IBM 2311/2314 and PCM equivalents including double density like the ISS 715 (RP03?). So some of the parts strippers should have lots. What parts str

RE: Can anyone identify what this board is/does?

My understanding is that DZU made disk storage subsystems including both drives and control units and that many if not all into the 1980s were copies of IBM disk storage products. The recollection is that IBM 2314 era SCU used a form of TROS where words were strips of film that punched a hole

RE: Tubbs fire consumed the collected archives of William Hewlett and David Packard

Apparently some of Hewlett's papers went to Stanford "Two new collections open for research: Helen and Newton Harrison & William Hewlett" http://library.stanford.edu/blogs/special-collections-unbound/2016/04/two-new-collections-open-research-helen-and-newton Tom -Original Message-

RE: IBM junk

What an incredible collection and thanks for taking the time to photograph it. It was great fun going thru the slides. From the content my guess is u were at least at some time at IBM SJ I understand u have a collector for all of it, but if by chance he/she and you have some original 3880

Early 12-inch WORM disk drives and media

I'm pulling together a timeline of optical computer data storage and having fun with the early ones. A copy of Rothchild's Optical Memory Report, From the early 80's would be appreciated - hardcopies are at the CHM so maybe I'll have to drive over there I'm told by a reliable source and am

RE: Maxtor full-height 5.25" drives of death

XT2190 was first produced in 3Q 1984 and last produced in 1989 which gives yours a remarkable life span and well beyond the them at most 5 year warranty. Be thankful they lasted this long. Tom -Original Message- From: Ian Finder [mailto:ian.fin...@gmail.com] Sent: Wednesday, February

RE: Computer tape quantities in the 70's or 80's?

Phister's numbers in Table II 1.27a Supplies Line Item Figure Units 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978

First 3.5 inch FDD [WAS: RE: Prototype IBM DemiDiskette drive]

Well it all depends upon what u mean by "first" The Sony drive and cartridge were not compatible in many ways with what became the physical, magnetic and electrical interface standards for the 3.5-inch drive and cartridge. The standards came out of the "Microfloppy Industry Committee" (Google it

RE: Prototype IBM DemiDiskette drive

It was the SA200 a 2/3rds height (51 mm) 5¼-inch FDD at $118 in quantities of 5,000 or more. It was sold in 1982 but got killed by the true ½ heights which Shugart OEMed from Matsushita. Tom -Original Message- From: Eric Smith [mailto:space...@gmail.com] Sent: Wednesday, August 22,

RE: DTC TakeTen media?

According to DTC's 1987 prospectus the Company began limited shipments of its TakeTen 10-megabyte removable-cartridge disk drive in December 1986. The TakeTen is based on technology developed by Data Technology in collaboration with Eastman Kodak. The storage cartridge is manufactured by

RE: First 3.5 inch FDD [WAS: RE: Prototype IBM DemiDiskette drive]

ony agreed to supply media comporting to the MIC standard. Both Tandon and Shugart showed drives at Comdex 1982; who shipped first in 1983 is unknown. Tom -Original Message- From: Chuck Guzis [mailto:ccl...@sydex.com] Sent: Thursday, August 23, 2018 12:20 PM To: Tom Gardner via cctalk S

An historical nit about FDDs

Anyone know where the Step/Direction version of the FDD interface originated. So far as near as I can tell the earliest FDDs (IBM 23FD Minnow and Memorex 650/651) used Step In/Step Out. The IBM 33FD Igar used direct control of the motor. The earliest Step/Direction FDD I can find is the Shugart

RE: An historical nit about FDDs

rom: Chuck Guzis [mailto:ccl...@sydex.com] Sent: Wednesday, July 11, 2018 11:38 AM To: Tom Gardner via cctalk Subject: Re: An historical nit about FDDs On 07/11/2018 11:12 AM, Tom Gardner via cctalk wrote: > Anyone know where the Step/Direction version of the FDD interface > originated. >

RE: An historical nit about FDDs

Jon: The 23FD used on most S/370 mainframes had a two solenoid and swash plate actuator, pulse the in solenoid to go in and the out solenoid to go out. IBM SJ in those days was very cost conscious and preferred mechanical parts over electronic, hence this mechanism instead of the stepper

RE: Researching IBM rare equipment from 50s to 80s

For the very early stuff u can't do much better than the US Army's Ballistic Research Lab surveys, a number of which are on line at http://www.ed-thelen.org/comp-hist/merged.html Tom -Original Message- From: Peter Van Peborgh [mailto:pe...@vanpeborgh.eu] Sent: Friday, December 14, 2018

RE: Documentation for Xebec Owl (a 1984 SASI-disk-drive)

In early 1984 I was in discussion with Jim Toreson of Xebec about selling them Shugart Corp's SA700 drive mechanics for use in the Owl. He went his own way and I'm pretty sure the Owl embedded the controller into the drive eliminating the ST-506 style interface. That would account for the

RE: Pleas ID this IBM system....

FWIW the tape drive is an IBM 2315 announced April 16, 1965 for use on low end S/360s. Here is a brochure as well as manuals at

RE: Damaged LTO tapes

Based upon my interviews for the Computer History Museum of IBM personnel involved in the development of LTO and its medium, I'd expect it to be very difficult to damage an LTO tape See: https://www.computerhistory.org/collections/catalog/102738025 particularly sessions 1 and 5 Tom -Original

RE: What is this?

There is a section in Bashe et al, Early IBM Computers that suggests Walnut only went to the CIA. The follow on project was Cypress beginning in 1962: “The main Cypress system, designed to store all information in digital form, was sometimes called the Trillion-bit File. This system was

RE: Unknown 1970 Tapedrive

The Sangamo Electric Co . manufactured electrical meters, time switches and sonar and radio equipment, among other items, in Springfield, IL from the 1890s until 1978. If your US house is old enough u might still have one of their meters on the

RE: Telex 20 Meg 10 platter very heavy monster drive needed drop line off list..r

ISS was an independent company in the era (late 60s) of the 714 (IBM 2314 compatible). It was later acquired by Itel (a leasing company) and then by Univac and sort of disappeared in the 80s. Depending upon your application almost any plug compatible 2314 might work or could be made to work.

Tape History - Freeman Reports

Hi I'm sure some of us all remember Freeman Reports as the chronical of the tape industry well into this century. Ray Freeman and his partner and successor Bob Abraham published these reports from at least 1983 until 2007 but with Bob's death in 2007 the reports and backup files apparently

One of Bay Area's last Fry's Electronics stores closes

Palo Alto Fry’s closing . Sad, but not the end of an era – apparently the loss of lease I remember visiting an early Fry’s (first?) in Sunnyvale (541 Lakeside Dr?, near Oakmead and around the

Standard Cocktail Napkin Size [WAS: RE: history is hard (was: Microsoft open sources GWBASIC)}

On Sunday, May 24, 2020 11:23 AM Fred Cisin via cctalk wrote in part: >> On Sun, 24 May 2020, Tom Gardner via cctalk wrote: >>The final media size was determined by Shugart Engineering led by Al >> Chou from the size of the 8-track tape drive that the 5¼-inch FDD was >

RE: history is hard (was: Microsoft open sources GWBASIC)

Fred Cisin [mailto:ci...@xenosoft.com] wrote on Saturday, May 23, 2020 11:28 PM Some don't matter; some can be enough to ruin a good anecdote; some create a different story. I'm saddened that Jim Adkisson and Don Massaro of Shugart have changed their story and now deny that the size

Early 3M Computer Tape Type Numbers

I'm trying to figure out what were the earliest Type numbers for 3M ½-inch reel-to-reel computer tape As best I can find, 3M began marketing a Type 777 computer tape about 1967. The Type 700 appears to be somewhat later. But 3M sold computer tape directly to at least government customers

RE: Early 3M Computer Tape Type Numbers

Also FWIW 3M Types 108, 109, 128 and 159 were advertised in 1958 as “instrumentation tapes” used for “critical recording work” on “… computers …” From: Tom Gardner [mailto:t.gard...@computer.org] Sent: Sunday, June 28, 2020 5:08 PM To: 'Paul Koning'; 'cctalk@classiccmp.org' Subject: RE:

RE: Early 3M Computer Tape Type Numbers

FWIW this is an announcement of a 3M brochure from a 1957 Datamation: Magnetic Tape for Instrumentation, an 8-page brochure, covers six types of "Scotch" brand instrumentation tapes for use in telemetering and airborne recording, machine tool control systems, computers, geophysical

RE: Early 3M Computer Tape Type Numbers

e: > > On 6/25/20 1:55 PM, Tom Gardner via cctalk wrote: >> I'm trying to figure out what were the earliest Type numbers for 3M >> -inch reel-to-reel computer tape >> >> As best I can find, 3M began marketing a Type 777 computer tape about 1967. >> Th

RE: BYTE Magazines

My understanding is that the Computer History Museum has a complete bound set - maybe Al can confirm And there is likely a fairly complete set at Stanford's GSB periodicals collection. Other computer or technical history museums might want a fairly complete set; e.g., Charles Babbage

First SCSI HDD - Priam 806 8-inch?

It turns out the Priam 806 8-inch SCSI HDD circa 1984 is likely the first HDD to have a native SCSI interface. It shipped a few months before the Xebec Owl which is likely second. AFAIK all earlier units had a bridge controller to a more conventional interface. If anyone has any different

Webinar: Ethernet's Emergence from Xerox PARC: 1975-1980

Ethernet invented in 1973-74 at Xerox PARC in Palo Alto, CA, evolved over many years. This April 13th Webinar will trace the history and development of Ethernet as a 10 Mb/s product up through the release of the DIX (DEC-Intel-Xerox) spec in 1980. This was the starting point for the ongoing

Origin of "partition" in storage devices

There is a discussion of the origin of the term "partition" in storage devices such as HDDs at: https://en.wikipedia.org/wiki/Talk:Disk_partitioning#Where_did_the_term_%22p artition%22_originate? It seems clear it was used in memory well before HDDs but when it got started there is unclear. * IBM

RE: Origin of "partition" in storage devices

FWIW a Google search: "partition site:http://www.bitsavers.org/pdf/dec/pdp11/rt11; returns no relevant hits prior to 1983 I suspect that ESDI and MFM controllers emulating RL/RK disks are also later than 1983 Tom -Original Message- From: Zane Healy [mailto:heal...@avanthar.com]

Re: Origin of "partition" in storage devices

A somewhat broader search found the 1984 RT-11 System Release Notes with the following: 1.4.2.4 Logical Disk Subsetting Handler (LD) - The logical disk subsetting handler lets you define logical disks, which are subsets of physical disks. You define logical disks by assigning a logical disk

RE: Question about DECtape formulation

> On Jan 24, 2022, at 10:27 PM, Gary Oliver via cctech wrote: > >> ... > > As to the real reason I was doing this: Most of my tapes are un-boxed and have suffered being in a dusty area (before I got them) with the dust forming a sort of 'crust' on the outside of the tape. It's only on the

RE: idea for a universal disk interface

I suggest if we are talking about an emulator it really isn't necessary to have the entire disk in DRAM, two tracks of DRAM acting as a buffer with a modern HDD holding the emulated drive's data should be fast enough to keep any old iron controller operating without missing any revolutions.

RE: idea for a universal disk interface

The IMI 7710 34 pin flat cable interface is a variant on the SMD dumb interface which could be controlled by a UDI (universal disk interface) if someone cared enough to build an adapter and then program the UDI to deal with IMI's specific track format and peculiar command/status protocol.

RE: idea for a universal disk interface

I haven't looked it up but I bet the head switch time is a lot longer than 1-2 usec - that's what the leading gap is for and the sync took most of the gap back in those days. The issue is sustained data rate isn't it? The ESMD raw data rate is 24 Mb/s but the formatted data is something

RE: idea for a universal disk interface

. Tom -Original Message- From: Fred Cisin [mailto:ci...@xenosoft.com] Sent: Wednesday, April 20, 2022 11:55 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: RE: idea for a universal disk interface On Wed, 20 Apr 2022, Tom Gardner via cctalk wrote: > Likewise, I don't k

RE: idea for a universal disk interface

I don't know it for certain, but I am pretty sure that it is true that virtually all controllers issue the commands in this sequence, Set Cylinder, Set Head and then Seek, or words to that effect. They then wait for Ready which can be 10's of milliseconds later. So there is plenty of time to

RE: idea for a universal disk interface

Agree that we are talking about two vastly different projects. Personally I think the universal disk reader is doable and interesting but expensive. Start with a clean bench having an air bearing variable speed motor and a universal mount to which various pack/cartridge adapters can be

RE: idea for a universal disk interface

-Original Message- From: Guy Sotomayor [mailto:g...@shiresoft.com] Sent: Friday, April 15, 2022 3:25 PM To: t.gard...@computer.org; cct...@classiccmp.org Subject: Re: idea for a universal disk interface I'm looking at what the spec says. ;-) The read command delay from the head set

RE: idea for a universal disk interface

-Original Message- From: Fred Cisin [mailto:ci...@xenosoft.com] Sent: Friday, April 15, 2022 3:54 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: RE: idea for a universal disk interface On Thu, 14 Apr 2022, Tom Gardner via cctalk wrote: > This was the approach IBM u

RE: idea for a universal disk interface

Interesting idea, there are three broad classes of HDD interfaces: 1. Dumb, that is serial data and parallel control 2. Intelligent parallel 3. Intelligent serial IMO if you can do dumb interraces then the others follow and given today’s technology I suspect it is feasible

RE: idea for a universal disk interface

-Original Message- From: ben [mailto:bfranc...@jetnet.ab.ca] Sent: Saturday, April 16, 2022 1:39 PM To: cctalk@classiccmp.org Subject: Re: idea for a universal disk interface On 2022-04-16 1:13 p.m., Tom Gardner via cctalk wrote: > Tom > How do you handle the disk hardware

RE: idea for a universal disk interface

Actually I am talking about emulating the bit stream, index to index - RLL encoded and containing gaps, marks, headers, data, CRC, ECC, etc. Exactly as the bit stream would come out of a theoretical disk drive, no bit shift, no write splices, no instantaneous speed variation, no long term

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

The only person who ever promulgated the "Dr. Wang bar napkin" story was Jim Porter who was not in any way involved with the decision as to the size of the 5½ drive or media size and only began telling his tale many years after the decision. Both Massaro and Adkisson deny there was ever such a

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

Sorry, there was no “U” consideration in the FH 5¼-inch form factor decision. It is 5.75 in × 3.25 in × 8 in; none of these have integer "U" relationships. SA engineering studied the various 8-track tape drives then available and found no standard form factor so they picked a set of numbers

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

on internet] >On Sun, 21 Aug 2022, Tom Gardner via cctalk wrote: > The only person who ever promulgated the "Dr. Wang bar napkin" story > was Jim Porter who was not in any way involved with the decision as to > the size of the 5½ drive or media size and only began tel

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

Fred: Please quote the current version of the oral history, It says: Porter: Jimmy said that you guys got together with the guys at Wang in a dark bar one night and, after a discussion, you decided on the size of what the smaller diskette should be and there was a cocktail napkin on the

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

That's one of the "features" of the CHM oral history archives, they keep older versions on line on "scholarly" principles. I've suggest they keep only the current version on line and include a change log to no avail Tom -Original Message- From: Fred Cisin [mailto:ci...@xenosoft.com]

[cctalk] Re: Floppy Disk Drive Controller History

WD was first and its line of FDCs with compatible suppliers competed with NEC/INTEL's line, see https://en.wikipedia.org/wiki/Western_Digital_FD1771 The IBM PC's usage of the uPD765 gave prominence to the NEC/Intel line. At this point I can't really say which if either came to dominate

[cctalk] Floppy disks for sale [WAS:RE: cctalk Digest, Vol 97, Issue 35]

Tom Persky at https://www.floppydisk.com/ sells all types of FDs, albeit well above the AOL price :-) Interesting article about this last man standing in the business: https://eyeondesign.aiga.org/we-spoke-with-the-last-person-standing-in-the-f

[cctalk] Floppy Disk Drive Controller History

I’m working on an update to Wikipedia on floppy disk drive controllers – there is a nice section on WD but nothing on Intel/NEC Anyone know the history of how the NEC µPD765 and the Intel 8272 became compatible devices? AFAICT it was IBM's August 1981 adoption of the NEC µPD765 in the PC

[cctalk] Re: Age of Tape Formats?

If you want authoritative sources I highly recommend: *IBM J. RES. DEVELOP. • VOL. 25 • NO. 5 • SEPTEMBER 1981, has an article “Innovations in the Design of Magnetic Tape Subsystems” *IBM Journal of Research and Development Vol. 47, No. 4, July 2003 has an article “Fifty years

[cctalk] Re: Nuking an MFM drive with a magnet, format/servo gone?

Well the data are still there and could be retrieved with a sophisticated servo on data system and/or a probe head on the data surfaces. Simpler to hit the spindle motor top dead center with a very large hammer ruining the bearings and crashing a few heads in the process. Even then the data are

[cctalk] Re: ST512 [WAS:RE: Re: Nuking an MFM drive with a magnet, format/servo gone?]

The ST512 was a thin-film head version of the ST506, per Seagate : "This increased capacity is accomplished by using the inner portion of the disc surface that was previously unused and by increasing the disc track density from 255 tracks per inch to 270 tracks per inch To reliably use the

[cctalk] Re: First non-IBM PC-DOS Compatible PC

s Sent: Monday, June 05, 2023 11:03 PM To: Tom Gardner via cctalk Subject: [cctalk] Re: First non-IBM PC-DOS Compatible PC On 6/5/23 22:28, Tom Gardner via cctalk wrote: > Can anyone identify a PC-DOS compatible PC announced earlier than October > 1984? Citations would be greatly a

[cctalk] First non-IBM PC-DOS Compatible PC

Hi: Doing some research for historical purposed – no litigation at all – trying to identify the first “legal” PC-DOS compatible PC, “legal” in the sense that it’s BIOS was not a copy of an IBM BIOS. Eagle gets the honor of being first MS-DOS compatible and getting sued for copying IBM’s

[cctalk] Re: The MAC at 40

-Original Message- From: Sellam Abraham Sent: Wednesday, January 24, 2024 2:16 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: [cctalk] Re: The MAC at 40 On Wed, Jan 24, 2024 at 2:04 PM Andrew Diller via cctalk <

[cctalk] IBM 350 disk and 305 drum [WAS:RE: Re: Drum memory on pdp11's? Wikipedia thinks so....]

The IBM 350 disk storage (RAMAC) has 5 million 6-bit characters or 3.75 MB; the actual recorded characters were 8-bits in length including a parity bit and a stop bit for each recorded 6-bit character It was announced as part of the IBM 305 RAMAC system which had drum memory which as far as

[cctalk] Re: IBM 360

Data Cell - Tape, Card or Disk? I'm pretty sure the developers thought of the media of the IBM 2321 as tape rather than cards, although the strips (of tape) were addressed as disk drives (DASD) not tape. It was a mechanical marvel that IMO then (late 60s) only IBM could have successfully built

[cctalk] Re: IBM 360

Gardner Subject: Re: [cctalk] IBM 360 > On Apr 12, 2024, at 2:10 PM, Tom Gardner via cctalk wrote: > > Data Cell - Tape, Card or Disk? > > I'm pretty sure the developers thought of the media of the IBM 2321 > as tape rather than cards, although the strips (of tape) were >

[cctalk] Re: PCs in home vs businesses (70s/80s)

Interesting discussion, but don't forget software was free until on June 23, 1969, when IBM announced its unbundled offerings! The computer manufacturers then separately priced their software but at it is what sold the hardware for some time thereafter. It was, for quite some time, always