8 Aug
2010
8 Aug
'10
5:20 p.m.
Pontus Pihlgren <pontus at Update.UU.SE> wrote:
Hi
I've acquired two PDP-11/44 and have just now gone throught the list of
cards in the cpu-boxes and the spares. Here is a list:
http://www.update.uu.se/~pontus/slask/11-44-kort.txt
Nice! You'll be able to put together atleast one really nice 11/44 from
that. I notice one FP11 in the list.
Also I wonder what the
"M7251 KG11-A U Network interface XOR and CRC block check option"
Just what it says, Network interface XOR and CRC block check option. :-)
Ok. The long answer then... You know about CRC-16 I assume?
This is hardware to generate that. You shove data to the card, one word
at a time, and you can read out the CRC value.
This card is, however, not very popular or useful, since software CRC
routines are actually faster on the PDP-11. DECnet can use this card if
you have it, but it's recommended that it not be used for this fact.
(The card is actually more generic, and can be used to generate any kind
of CRC checksum, not just CRC-16.)
"M3110 DRCSA U Protocol assist #1
w/special character check and CRC (DEC/DLC/DRCSA)"
"M3111 DRCSA U Protocol assist #2 w/special character check and CRC
(DEC/DLC/DRCSA)"
No clear idea about those two...
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
9 Aug
9 Aug
1:44 a.m.
snip snip snip
I checked with a co-worker (who did service PDP-11's)
He thinks it may have been used as X.25 router/ lineinterface.
Usually there is also a M3112 card (boot/terminator for DECSA)
Ed
--
Dit is een HTML vrije email / This is an HTML free email.
"M3110 DRCSA U Protocol assist #1
w/special character check
and CRC (DEC/DLC/DRCSA)"
"M3111 DRCSA U Protocol assist #2 w/special character check
and CRC (DEC/DLC/DRCSA)"
No clear idea about those two... 
1:24 p.m.
snip snip snip
I checked with a co-worker (who did service PDP-11's)
He thinks it may have been used as X.25 router/ lineinterface.
Usually there is also a M3112 card (boot/terminator for DECSA)
I _knew_ I recognised thase numbers...
You are essentially right. They are essentially a custom 'processor' for
X25 and other protocols used in the DECSA (Digital Ethernet
Communications Server Aparatus or something similar).
A DECSA is a special cabinet containing a PDP11/24 CPU, a boot/terminator
board, those 2 protocol cards, RAM, a DEUNA (ethernet interface) and one
or more line cards (dual height, in special slots). It's a sort of
terminal server/X25 interface/etc
I have one, and it led me to propose 'ARD's law of DECSA construction'
which states 'The lower the importnace of a part of a DECSA, the more
screws hold it in place'. This is illustrated by
The logic boards plu in with no screws
The PSU(s) are held in by 2 screws (each, if you hve 2 PSUs)
The fan tray is held in by 4 screws (this is less important than the
above, the thing will run for a short time with no fan tray).
But the metal grille over the fan tray is held on by an amazing 28 screws
(I had to take them all out and put them all back to remvoe the fan tray
before removing the backplane...
-tony
"M3110 DRCSA U Protocol assist #1
w/special character check
and CRC (DEC/DLC/DRCSA)"
"M3111 DRCSA U Protocol assist #2 w/special character check
and CRC (DEC/DLC/DRCSA)"
No clear idea about those two... 
6 Sep
6 Sep
9:29 p.m.
New subject: RRD50 interface
Sorry for the mis-threading, I lost the original posting.
The older CDROM drives were in fact CD audio drives with the logic bolted
on in place of the serial DACs. In fact I used to have an old Reference
Technology drive which was a commercial CD drive and several boards worth
of discrete logic which performed the C3 ECC correction. The CDROM
functionality was just connected in place of the DACs.
I suspect the RRD50 interface is three main wires:
Bit clock (32x data rate)
Left/Right (high for left, low for right, or vice versa)
Serial data
And, if memory serves it was called an I2S interface, though what the
acronym stands for I don't recall.
Unfortunately, I don't have any documentation of the parts I worked on for
Cirrus Logic from the early CDROM projects. Those drives were based on a
CD audio DSP chip (analog, servo, laser control, C1 & C2 ECC) and a
backend chip (C3 ECC, cache memory, and ATA interface).
Sony was the primary supplier of the DSP chips and Cirrus, Oak Technology,
and a few others made the backend chips. A perusal of the CD documents
(Red book) and CDROM document (Yellow book) might sheds some light on it
all.
Clint
10:07 p.m.
New subject: RRD50 interface
cctech at vax-11.org wrote:
I suspect the RRD50 interface is three main wires:
Bit clock (32x data rate)
Left/Right (high for left, low for right, or vice versa)
Serial data
And, if memory serves it was called an I2S interface, though what the
acronym stands for I don't recall.
The RRD50 is a Philips/LMSI CM100 CD-ROM drive, which was based on the
Philips CD100 CD player. There was a CM155 host adapters for PCs.
I used to have the CM100 and CM155 service manuals, but don't have them
readily available now. This site claims to sell a PDF of the CM100
service manual for $29:
http://www.manuals-in-pdf.com/index.php?main_page=product_info&products…
However, it might be a manual for the Philips CM100 Transmission
Electron Microscope, rather than the Philips CM100 CD-ROM drive. It
would have been nice if Philips hadn't used the same model number for
two entirely different products.
The CM100 interface is not I2S; there are I2S or similar signals inside
the drive, but there's a bunch of logic that reformats the data for the
interface. The interface uses EIA-422 differential pairs. IIRC there
were one or two pairs for the data, one for commands to the 8051
microcontroller, and one for status back from the 8051.
The drive hardware does not perform the C3 error correction; that is up
to the host adapter or the host. The CM155 is a very dumb adapter, so
the driver must do the C3 error correction.
I spent some time reverse-engineering the 8051 firmware, though truth be
told, there isn't really much of interest in there.
Oddly enough, they came very close to implementing the CM100 interface
in such a way that multiple drives could be used on one host adapter, by
assigning them unit numbers on the DIP switch, but they didn't put in
the EIA-485 drivers that would be necessary to make it work. (EIA-422
does not define drivers with a high-impedance state, while EIA-485 does.)
Sony was the primary supplier of the DSP chips and
Cirrus, Oak
Technology, and a few others made the backend chips.
The CM100 uses the Signetics
SAA7000 series CD-Audio chipset, since
Signetics was owned by Philips.
There was a CM110 which had an additional board that adapted the CM100
interface to SCSI. I'd like to find one of those, or the M7552 (KRQ50)
or M7490 host adapters for the RRD50, but I haven't ever found them.
Eric
10:35 p.m.
New subject: RRD50 interface
On 9/7/10 1:07 AM, Eric Smith wrote:
There was a CM110 which had an additional board that
adapted the CM100
interface to SCSI. I'd like to find one of those, or the M7552 (KRQ50)
or M7490 host adapters for the RRD50, but I haven't ever found them.
I have at least two KRQ50 boards here, but they've been raped for
parts; I think there's a PLCC socket or similar that's empty on both of
them, perhaps EPROMs too. Let me know if you want to research this
further; I can dig them out in about two weeks when I'm back and settled
in from my road trip
-Dave
--
Dave McGuire
Port Charlotte, FL
7 Sep
7 Sep
11:04 a.m.
New subject: RRD50 interface
There was a CM110 which had an additional board that
adapted the CM100
interface to SCSI. I'd like to find one of those, or the M7552 (KRQ50)
or M7490 host adapters for the RRD50, but I haven't ever found them.
I thnik I was given a CM110 many yuars ago. If so, I still have it (I
never throw anytthing away...) ut don't expect me to know where it is. I
would love to see a service manual for that, from what I rememebr I could
recgnise most of the chips inside it, but there were a couple of custom
ones...
-tony
11:01 a.m.
New subject: RRD50 interface
Sorry for the mis-threading, I lost the original posting.
The older CDROM drives were in fact CD audio drives with the logic bolted
on in place of the serial DACs. In fact I used to have an old Reference
I have (and still use) an ancient external Philips single-speed CD-ROM
drive (CDD462) which is a modified (by Philips) CD player. To the exptent
that you need both its service manual and the one for the CR player it
was based on to repair it.
In fact for the one fault I've had with it, the CD-ROM drive service
manual was not a lot of help. The mains switch failed. Yes, it's shown on
the schematics, but for some reason not listed in the parts list. It is
listed in the CD player manual, so I could order a replacement.
IIRC, there is a ULA-type thing conencted to the input of the DACs which
extracts the right bit of the bit-stream and sends it to the interface
card in the PC (one ASIC and a buffer RAM). There's also a serial
command/status link from the PC to the control microcontroller in the
CD-ROM drive, to let the PC select the block to start reading from, etc.
The main CD-player chipset was still there, it was the Philips one, of
course, as docuemtned in their data books.
Technology drive which was a commercial CD drive and
several boards worth
of discrete logic which performed the C3 ECC correction. The CDROM
That sounds like fun...
functionality was just connected in place of the DACs.
The Philis unit I mentioned kept the DACs, and even the headphone
amplifdier. It ahs the normal play/stop/prev/next buttons on the front,
and can be used as a CD-player without having a computer conencted.
I suspect the RRD50 interface is three main wires:
Bit clock (32x data rate)
Left/Right (high for left, low for right, or vice versa)
Serial data
And, if memory serves it was called an I2S interface, though what the
acronym stands for I don't recall.
I2S = Inter IC Sound (at least in this case [1]). There's also the
totally different, but also from Philips I2C (Inter IC Communication)
[1] Long before this there was an American company called IIS or I2S
(I've seen both) standing for International Imaging Systems or something
like that. They made some very nice image processor/display units for
PDP11s
-tony
5002
days inactive
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7 comments
6 participants
participants (6)
-
ard＠p850ug1.demon.co.uk -
bqt＠softjar.se -
cctech＠vax-11.org -
eric＠brouhaha.com -
mcguire＠neurotica.com -
quapla＠xs4all.nl