8D77 (4-4) SCSI SE High Performance
Internal/External I/O Controller FC 2410, 2831
(52G5484, 52G5483, 52G7504, 52G7509, 11H4779, 11H4780, 52G1171, 2410, 2830)
SCSI-2 SE I/O Controller (Type 4-4):
OK, what do we got?
What the 4-4 supports:
Accepts multiple commands per device at a time from
SCSI-2 data rate of up to 10MB per second (synchronous
Streaming Data Support [I think it MUST support
Bus Fairness as well]
Address and Data Parity Support
Supports Command Tagged Queuing (as SCSI initiator)
Interrupt levels 3, 4, 5, 7, 10, 11, 12, 14
HPDB50 external SCSI Port [Oh YES! YES!]
SCSI I/O Controller 4-4,
|D1 - Diode
DL1,2 bel 0401-1403-11
J1 - High Availability
U9 WD33C93BJM 00-02 or 00-04
U4 32G0215ESD Big silver chip
U26 PLCC44 ???
Y2 39.9500 MHz
All versions of the 4-4 use 32G0215ESD [Entry Systems
Division]. There seems to be a connection between the
later production dates and the "00-04" revision of the
32G0215 Laser Etched - 93-ish mfr, "00-02" WD33C93B
32G0215 Ink Printed - 95-ish mfr, "00-04"
32G0215ESD MCA Bus interface ???
0401-1403-11 High-Speed 4 Pin SIP Passive Delay
0401-1403-11 Total Delay 5.0 +/- 0.25 ns,
Rise Time (True) 1.1 ns, DCR Max 1.0 Ohm
bel App 1-R1
Pulse Shaping / Clock Pulse Generation Circuits
Y2 is a 39.9500 MHz osc, that provides an input clock
to the WD33C93B
"When the 33C93B has an input clock between
16 and 20 MHz, ... the host can select... Fast
synchronous transfers with a peak rate of 10 MB/s on
both the SCSI and host DMA interfaces."
I also suspect that 39.9500 MHz osc is used to provide
the clock [suitably divided] for other components.
Three possible firmware chips, the socketed PLCC44
[U26], the socketed DIP-20 [U22], and the surface
mounted PLCC [U47]above the 80C186XL20.
I see two digital signal regenerators [DL1,2] between
the DIP-20 and the 32G0215.
J1 (also called P3) High
Must be out of the circuit for high availability
("Y") configuration. Put the jumpers over one row only
so you don't loose them. There are 13 pairs of pins. You
will need a 6 and 7 pair berg jumper (ganged jumper) in
order to use this for normal SCSI configuration..
P3 High Avail Jumper 2 pieces 42F7525, 42F7526
So, can we make a kludge of an internal terminator
using the J1headers? DIP or SIP resistor network?
TERMINATORS (Purpose and Usage)
Terminators: The FPT-3 is generally
used on the the internal end of the cable, and the
FPT-18 is used on the external end of the cable.
non-FPT: passive. Internal/External SCSI bus
limited to two external
FPT-3 : actively terminates only three SCSI bus
lines: ACK, REQ, SEL.
FPT-18 : active. 18 lines of SCSI bus, [eight data
lines]. No longer manufactured.
FPT-18+: active. 18 lines Functionally equivalent and
fully interchangeable with FPT-18.
SCSI Termination From HERE
FPT is an even better form of active
termination, in which diode clamps are added to
eliminate signal overshoot and undershoot. The trick is
that instead of clamping to +5 and ground, these
terminators clamp to the output of two regulated
voltages. This arrangement enables the clamping diodes
to eliminate signal overshoot and undershoot, especially
at higher signaling speeds and over longer distances.
FPT is technically not found in the SCSI specifications
but is a superior type of termination for SE
applications that experience high levels of electrical
FPT terminators are available in several versions.
FPT-3 and FPT-18 versions are available for 8-bit
standard SCSI (Figure 7.18 shows the schematic for an
FTP-18 terminator), whereas the FPT-27 is available for
16-bit (Wide) SCSI. The FPT-3 version forces the three
most highly active SCSI signals on the 8-bit SCSI bus to
be perfect, whereas the FPT-18 forces all the SCSI
signals on the 8-bit bus except grounds to be perfect.
FPT-27 also forces all the 16-bit Wide SCSI signals
except grounds to be perfect.
FPT-18 SCSI terminator
Card edge, FPT-3 00G0972 "50-position
card edge terminator"
70F9900 Old card edge non-FPT Terminator. Sub to
External Terminator for HPDB50 Port
50-Position External Terminator
50-pin, high-density, external,
Note: 52G4259 replaces FPT-3 00G2223, 51G7737, and
FPT-18 43G0378. All are usable.
Black FPT-18C (different
Same P/N (52G4259) and EC (D18561).
My SWAG is that IBM moved from the AMP metal shell to
the black one due to cost. I can't verify the
electronics being the same, but they probably are...
External Terminator for C50 Connector
on External SCSI Cable
50-pin, low-density, external, FPT-18+ 51 51G7736
50-pin, low-density, external, FPT18C 52G4260
Note: 52G4260 replaces FPT-3 00G0968, FPT-18 43G0467,
and FPT-18 51G7736. All are usable.
FPT-18 43G0378 ?
Stephan Goll says:
To make a summary: AIX has a database called
ODM. In this database there are the definitions and
suggestions for configuring all the cards not configured
before IPL. Cards where AIX can boot from, well, should be
configured somehow, I believe by the ROS (or BIOS). Makes
sense, because only the ROS knows from where the box can
IPL. And remember, AIX uses a two stage boot process,
first it boots in minimal mode, configures the cards using
the ODM, and then it boots again with the system fully
configured (so it is written in my AIX survival guide).
Overload Protection and
Terminator Power (Term Power)
The SCSI controller provides term power for
the SCSI bus; connect devices to the bus so they do not
provide term power. The controller uses a fuse that must
be replaced after failure.
Do not connect or disconnect any SCSI device
while power is on. Such “hot plugging” is forbidden
because this practice may blow the controller fuse,
corrupt data or permanently damage SCSI controller chips
in controllers or devices.
The fuse on an SCSI controller protects the
external and internal SCSI bus. The fuse may be blown by a
defective cable, terminator, or device attached to the
controller, but not by a defective controller.