15 Aug
2013
15 Aug
'13
2:04 p.m.
Hi Camiel
I agree; it could be identical twins.
The electronics for head movement etc. sounds reasonable, so I think there
is a fair chance that the drives are identical, apart from the number of
segments per track. Al Kossow thinks there might be more to it, but we don't
get nervous about the problems; not ntil we meet them anyhow.
The controller looks identical, or to more more precise, all controllers
have same layout (size, connectors, ...)
I have not yet laid my eyes on the diskcontroller, but it has the same size
as the CPU and RAM boards etc.
which cannot surprise me, as the PTS is based on P800 parts as far as
possible (operator console, tapedrive, card reader, CPUs, RAM, tape-/disk
controller ectc.).
I have now finished reading the tapes I have at home. There are 40, 18 of
which contained various PTS software. The rest was blank, used for other
purposes, had no BOT blink, or could not find the first block. It is not
sure that all tapes came from PTS. The 18 tapes mentioned, were read
flawlessly, apart from 2 read errors. That is quite an achievent after some
30 years of storage.
I also think that some of the 22 nogo's can be read on the tape drive that
wrote them; it is a Pertec 1600 BPI only drive
Next week I'll start putting a system together
Regards
Nico
----- Original Message -----
From: "Camiel Vanderhoeven" <iamcamiel at gmail.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Thursday, August 15, 2013 10:24 PM
Subject: Re: IBM 5440
Hi Nico,
I'll check for any IBM labels when I get home on Saturday, but I don't
recall seeing any. Physically, the drive looks suspiciously similar to
the IBM 5444 at
http://www.theinquirer.net/inquirer/news/2074995/ibm-pictures-hardware-base…,
including the location of the spindle motor, and the big clamps on the
side.
The actual data to/from the drive is almost raw; there's just a
bitstream (at TTL level) from the controller to the drive to write,
and from the drive to the controller to read. So, other than
amplification and bit-shaping there is no processing in the drive (no
de-serialization); there is a fair bit of electronics in the drive for
seeking and head selection, though.
What does your interface look like? The CDD (cartridge disk drive)
controller in the P850 has a 74 pin card edge connector. Does your
controller look like the one in this picture on my website:
http://p800.wikispaces.com/CDD ?
Camiel
On Thu, Aug 15, 2013 at 5:22 PM, Nico de Jong <nico at farumdata.dk> wrote:
>
> ----- Original Message ----- From: "Al Kossow" <aek at
bitsavers.org>
> To: <cctalk at classiccmp.org>
> Sent: Thursday, August 15, 2013 3:09 PM
> Subject: Re: IBM 5440
>
>
>> On 8/15/13 3:26 AM, Nico de Jong wrote:
>>>
>>> Hi all
>>> Would anyone know where I can find a IBM 5440 diskdrive, or even better
>>> :
>>> a Philips 6875? They both use IBM 5444 cassettes, although with a
>>> different
>>> number of segments per track
>>> Nico
>>>
>>
>> There were many, many companies that made OEM 5440-style disk drives,
>> most
>> had slightly incompatible
>> interfaces or cabling from each other. Are you sure what you are looking
>> for are real IBM drives?
>>
>> Looking at the X121x drive service manuals at
>> http://p800.wikispaces.com/Docs those drives are clearly European
>> designs at quite unlike IBMs (TTL logic and different head positioning
>> technology). The 2.5 vs 5 Mb difference
>> will be 200 vs 400 tracks.
>>
> Well, when I look at the product specification, it is specified that ibm
> 5444 cartridges are used. The way I read the hardwaredocumentation, the
> Philips machine takes the raw data, which could/should mean that no
> logic/pre-handling is done in the drive. Of course I could be wrong.
> I'll take a look at the p800 docs.
>
> Camiel, should there be an IBM label besides the X12.. drives you have?
> Or
> maybe something else indicating where the drive came from?
>
>
> Nico
>
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