Hello!
Why did the early PeeCees wear 528 Megabyte drives as their largest
drives? (This despite the fact that to use it, the early operating
systems would also be size confused.) The BIOS the computers wear was
problematic.
In this case Cory is right, lack of determination. Plus other things.
-----
Gregg C Levine gregg.drwho8 at gmail.com
"This signature fought the Time Wars, time and again."
On Fri, Oct 11, 2013 at 3:54 PM, Cory Smelosky <b4 at gewt.net> wrote:
On Fri, 11 Oct 2013, Dave McGuire wrote:
On 10/11/2013 02:13 AM, Mark Benson wrote:
http://www.artmix.com/SATA_SCSI_AZMN_II_1.html
This adapter is available on ebay for $149 and he says they work well
in Vaxstations. He also has some which take CF flash cards.
Which is great, but again you run in to the snag that I've never seen a
SATA disk smaller than 40GB and the upper size limit on a VAXstation is
typically 18GB. Somewhat problematic.
I have 2 20G laptop SCSI drives...
WHY does this keep coming up? There is no such limitation!
Lack of determination.
-Dave
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On 11 Oct 2013, at 20:59, Mark Wickens <mark at wickensonline.co.uk> wrote:
On 11/10/2013 20:54, Cory Smelosky wrote:
On Fri, 11 Oct 2013, Dave McGuire wrote:
WHY does this keep coming up? There is no such limitation!
I'm easily confused
Yes it's his fault! I blame him entirely! ;)
--
Mark Benson
http://DECtec.info
Twitter: @DECtecInfo
HECnet: STAR69::MARK
Online Resource & Mailing List for DEC Enthusiasts.
On 11/10/2013 20:54, Cory Smelosky wrote:
On Fri, 11 Oct 2013, Dave McGuire wrote:
On 10/11/2013 02:13 AM, Mark Benson wrote:
http://www.artmix.com/SATA_SCSI_AZMN_II_1.html
This adapter is available on ebay for $149 and he says they work well
in Vaxstations. He also has some which take CF flash cards.
Which is great, but again you run in to the snag that I've never seen a
SATA disk smaller than 40GB and the upper size limit on a VAXstation is
typically 18GB. Somewhat problematic.
I have 2 20G laptop SCSI drives...
WHY does this keep coming up? There is no such limitation!
I'm easily confused...
--
http://www.wickensonline.co.ukhttp://hecnet.euhttp://declegacy.org.ukhttp://retrochallenge.nethttps://twitter.com/#!/%40urbancamo
On Fri, 11 Oct 2013, Dave McGuire wrote:
On 10/11/2013 02:13 AM, Mark Benson wrote:
http://www.artmix.com/SATA_SCSI_AZMN_II_1.html
This adapter is available on ebay for $149 and he says they work well
in Vaxstations. He also has some which take CF flash cards.
Which is great, but again you run in to the snag that I've never seen a
SATA disk smaller than 40GB and the upper size limit on a VAXstation is
typically 18GB. Somewhat problematic.
I have 2 20G laptop SCSI drives...
WHY does this keep coming up? There is no such limitation!
Lack of determination.
-Dave
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On 10/11/2013 02:13 AM, Mark Benson wrote:
http://www.artmix.com/SATA_SCSI_AZMN_II_1.html
This adapter is available on ebay for $149 and he says they work well
in Vaxstations. He also has some which take CF flash cards.
Which is great, but again you run in to the snag that I've never seen a
SATA disk smaller than 40GB and the upper size limit on a VAXstation is
typically 18GB. Somewhat problematic.
WHY does this keep coming up? There is no such limitation!
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
No, that would not be legal (and in fact the DEC FDDI chips contain specific machinery to detect and remove duplicate tokens should any show up). Sridhar was talking about a switch (bridge), so each port is a separate LAN and as such has its own circulating token.
paul
On Oct 11, 2013, at 2:04 PM, Hans Vlems <hvlems at zonnet.nl<mailto:hvlems at zonnet.nl>> wrote:
Wouldn't that mean more than one token on a ring?
Van: Sridhar Ayengar
Verzonden: vrijdag 11 oktober 2013 19:55
Aan: hecnet at Update.UU.SE<mailto:hecnet at Update.UU.SE>
Beantwoorden: hecnet at Update.UU.SE<mailto:hecnet at Update.UU.SE>
Onderwerp: Re: [HECnet] FDDI advice
Paul_Koning at Dell.com<mailto:Paul_Koning at Dell.com> wrote:
Half duplex Ethernet slows down when there are collisions, but there
is no wait to transmit whenever the link is idle. With FDDI, there
is (you wait for the token). So at high load, half duplex Ethernet
might be a little slower than FDDI, but at modest load, it will
definitely be faster (lower latency).
But, doesn't the GIGAswitch get around that by generating a token for
each port? Isn't that how switched-FDDI works?
Peace... Sridhar
Wouldn't that mean more than one token on a ring?
Van: Sridhar Ayengar
Verzonden: vrijdag 11 oktober 2013 19:55
Aan: hecnet at Update.UU.SE
Beantwoorden: hecnet at Update.UU.SE
Onderwerp: Re: [HECnet] FDDI advice
Paul_Koning at Dell.com wrote:
> Half duplex Ethernet slows down when there are collisions, but there
> is no wait to transmit whenever the link is idle. With FDDI, there
> is (you wait for the token). So at high load, half duplex Ethernet
> might be a little slower than FDDI, but at modest load, it will
> definitely be faster (lower latency).
But, doesn't the GIGAswitch get around that by generating a token for
each port? Isn't that how switched-FDDI works?
Peace... Sridhar
On Oct 11, 2013, at 1:55 PM, Sridhar Ayengar <ploopster at gmail.com> wrote:
Paul_Koning at Dell.com wrote:
Half duplex Ethernet slows down when there are collisions, but there
is no wait to transmit whenever the link is idle. With FDDI, there
is (you wait for the token). So at high load, half duplex Ethernet
might be a little slower than FDDI, but at modest load, it will
definitely be faster (lower latency).
But, doesn't the GIGAswitch get around that by generating a token for each port? Isn't that how switched-FDDI works?
On token LANs there's a token per LAN. Yes, if you bridge token LANs, each LAN has its own token. That's true for all bridges, it's a consequence of what a bridge is.
But still, on any one LAN, the stations have to wait for the token. That is, unless you have exactly two MACs, and they are DEC stations that support the DEC full duplex mode. If so, you have no token, and the link operates essentially the same as Ethernet in full duplex mode (except for header format and min/max packet sizes).
paul
Paul_Koning at Dell.com wrote:
Half duplex Ethernet slows down when there are collisions, but there
is no wait to transmit whenever the link is idle. With FDDI, there
is (you wait for the token). So at high load, half duplex Ethernet
might be a little slower than FDDI, but at modest load, it will
definitely be faster (lower latency).
But, doesn't the GIGAswitch get around that by generating a token for each port? Isn't that how switched-FDDI works?
Peace... Sridhar
On Oct 11, 2013, at 1:25 PM, Kari Uusim ki <uusimaki at exdecfinland.org> wrote:
Thanks Paul for the detailed clarification!
On 11.10.2013 17:23, Paul_Koning at Dell.com wrote:
On Oct 11, 2013, at 2:28 AM, Kari Uusim ki <uusimaki at exdecfinland.org> wrote:
...
Yes, that would be the one when converting between FDDI and 100BaseT Ethernet.
The best effort it can produce is about what 100BaseT can, because it is the lowest common nominator. FDDI performs better due to the larger packet size (which is usable only between FDDI nodes) and the lower overhead.
Larger packet size, yes. Lower overhead, no. Token systems of any kind are guaranteed to be less efficient than Ethernet, because you have to wait for the token. At best, they will be slightly better under very high load than half duplex Ethernet, but full duplex Ethernet will outperform any token network under all conditions.
It's very clear that FDDI will outperform half duplex Ethernet, because there will not occur any collisions in FDDI.
But if we think about a FDDI-to-100BaseT (Full duplex) topology and the traffic flows with as large packets as possible, doesn't FDDI be able to carry about three times more payload in each packet than Ethernet? In that case one FDDI packet payload will need to be split into three Ethernet packets and three Ethernet packet payloads will fit into one FDDI packet.
Yes, the smaller packet size of Ethernet means the CPU does per-packet processing 3 times as often, which has a performance impact. (Pretty small, if the CPU is fast.) And three headers instead of one makes a difference, but only a bit over 1%.
Half duplex Ethernet slows down when there are collisions, but there is no wait to transmit whenever the link is idle. With FDDI, there is (you wait for the token). So at high load, half duplex Ethernet might be a little slower than FDDI, but at modest load, it will definitely be faster (lower latency).
paul
