CDC Finch Alternatives Today [WAS:RE: Evotek Winchester Harddisk]
lehmann at ans-netz.de
Wed Dec 9 14:12:54 CST 2015
they definity mean not SMD with "CDC" as for SMD a complete different
controller exists for the system which explicitly is for SMD drives
Tom Gardner <t.gardner at computer.org> wrote:
> The manual u cited states, "The disk controller can control either a
> CDC or Finch drives. All drives attached to any controller must be
> of one type." I'm not sure what they mean by "CDC" but if u are
> lucky it might mean "SMD."
> According to the 1983 Disk/Trend Finch interfaces were available on
> the Wren 9415-32 (Finch and ST506) and the Wren 94153 (Finch only).
> So u might look for a 94153 or a Finch variant of the 9415-32.
> The Finch spec data interface specs include 13440 unformatted bytes
> per revolution using an 806 KB/sec data rate, which are the very
> old at that time 3330 industry standards. There are very few small
> drives that use this standard, not even the 94153 (10,080 @ 605
> KB/sec) so what happens with the drive at a different frequency and
> the controller with a possibly a different number of raw bytes per
> track is unpredictable. Note that 10080 x 806/605 is close enough
> to 13440 so any 10,080 @ 605 KB/sec drive might be made to work if
> the recording channel has margin at the higher frequency;
> unfortunately there are not very many.
> A bigger problem might be the command and control interface of the
> Finch - it is not like the ST506/412. Off the top of my head it
> looks like a variant on SMD. BTW SMD data specs are exactly
> 1.5x3330, that is 20,160 bytes @ 1.209 MB/sec so a small SMD might
> work if the recoding channel can deal with the lower data rate,
> perhaps the 8715 FSD. You might want to compare pin by pin SMD to
> Finch to see if this is even possible. There were some small SMDs,
> e.g. Micropolis 1403, Priam 804 but most were 14-inch.
> Perhaps there is a CDC SMD expert in this group that can help
> -----Original Message-----
> From: Oliver Lehmann [mailto:lehmann at ans-netz.de]
> Sent: Monday, December 07, 2015 11:39 AM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: Evotek Winchester Harddisk
> Tom Gardner <t.gardner at computer.org> wrote:
>> Sorry If I didn't make myself clear, I am suggesting one never acquire
>> an Evotek drive today other than perhaps as an historical curiosity.
>> The Finch was a short lived 8-inch HDD that went up to 42 MB
>> unformatted BUT according to Disk/Trend It did not use an ST506
>> interface but instead came with this variety of interfaces: Finch,
>> LDI, SMD or SA1000! So your problem is likely to be finding a drive
>> that matches the interface of yr controller card. Some possibilities
>> Finch interface was available on certain CDC Wren 5 -inch
>> models, e.g. 9415
> From what I understood in the Zilog System 8000 manuals, it is the
> Finch interface.
> Page 33 - Drive Performance Characterstics Page 47 - Pinout of the
> WDC-Controller Disk Connector Page 65-69 - Describing Driver
> Here are pictures of harddisks used in the System 8000:
> And this is the so called "FINCH Adapter Board" used in the S8000:
More information about the cctech