Sun SPARCstation IPX
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(pictures copyright by M.A.Grundke)
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serial number:
600-2886-02
246MZ896 |
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type plate:
sun
microsystems
ELECTRICAL RATINGS: AC 100-240V, 47-63 Hz, 5A
MODEL NUMBER: 47B
SERVICE CODE: 4/50
And then the serial number again. There are also lots of patents and copyrights mentioned. By the way, this machine was sold by the german Kodak AG as a printspooler (see sticker) |
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SPARCstation IPX (4/50) board overview:
the SPARCstation IPX's board is highly integrated. With all important components onboard, it's a complete workstation in the compact 'lunchbox' design. It's dominated by the large SunGX framebuffer controller, the Weitek 8601 CPU and the AT&T CACHE+ (middle, from left to right). Below them, the two SBus slots for internal expansion. Below the SBus are the four RAM sockets (U0307-U0310), one fitted with a 4Mx33 DSIMM, and the internal SCSI connector below. Right from the RAM bank an AT&T RAM+ (U0323), with floppy connector below and boot PROM/ NVRAM further right. You can also spot the internal speaker there.
Below NVRAM, right from the RAM+ and above power connector the small Intel N82072 (U0505). Above the boot PROM the AT&T MMU+ (U0210), and still above are 7 SRAMs (at U0201 and U0204-U0209, right from the CACHE+). Now to the board's upper part - from left to right, starting above the SunGX: 8 SRAMs (U0901-U0908) (video RAM for the Bt458 (U1001) to their right). Right from the Bt458 is the AMD79C30 (audio, U0601), with two AMD85C30 (U0506, U0507) further right and two AT&T ATT7C157M (16Kx16 SRAMs at U0102, U0103) below (above CPU and CACHE+). Below the second 85C30 (at U0506) is a silkscreening, by the way, which one of the layouters' cat. Moving right again are UC5170 & UC5180 (U0518, U0519) with jumpers J0502 & J0503 below. Rightmost, an AT&T 1119A (U0405)
with NCR 53C90A (U0401) above it. Then, left from the NCR, are an AMD7990 (U0402) and an AMD7992 (U0403, small IC), forming the AMD 'Lance' ethernet chipset. Finally, there are two board edge connectors on the board's front side (below RAM bank, SCSI- and floppy connectors). I assume they were used for diagnostics (burn-in tests, probably) |
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board silkscreening, part 1:
MODEL 450 CPU
N572931717M7602724 |
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board silkscreening, part 2:
ICL © 1991 MADE IN UK |
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board silkscreening, part 3:
100803 PBN 270-1959-02 |
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| The SPARCstation IPX's CPU, a Weitek W8601-040. It's running at 40 MHz and has on-chip floating-point unit. It makes a good 28 MIPS, which is not bad considering the age of the machine! However, there were also machines that came with Weitek W8701 or Fujitsu MB86903-CPUs. All these CPUs, however, are implementations of the SPARC v7 RISC-design, which was introduced with the Sun-4 architecture and featured an unified data and instruction-cache, and a four-stage integer pipeline. In earlier machines, Sun had used Motorola 680x0 CPUs (MC68000 in the Sun-1 series, 68010 in
the Sun-2s and 68020/ 68030 in the Sun-3s) - there was even a short-lived Sun i386 series (namely 386i/150 and 386i/250). Interesting to know in that context is that Sun had negotiated with Commodore about OEM-marketing the Amiga 3000 as a Sun-3 workstation, which was declined by Commodore management - one of Commodore's biggest mistakes, if you ask me |
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| Part of the machine's memory management, an AT&T CACHE+ 1130A3. This chip contains 1 MByte cache for the CPU! |
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| These are the machine's 64K external CPU cache, operating in write-though mode (=data to be cached is written to cache and RAM simultaneously). These ATT7C157 (16Kx16 SRAMs) have been especially designed for the use with SPARC-systems and have been released by AT&T in 1991. The 18- and 20ns versions are suited for 40MHz SPARC-designs (like the IPX), but there was also a 15ns-variant for 50MHz SPARCs. Since these SRAMs interface directly to the machine's cache controller (MMU+, RAM+?), there's no need for additional glue logic (effectively reducing production cost) |
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| These SRAMs seem to be 80 KB additional cache, consisting of one 32Kx8 SRAM (Toshiba TC55328J-20) and six 16Kx4 SRAMs (Toshiba TC55417J-20H). Purpose unknown, but most likely they're used as an additional buffer for the onboard components (ethernet, audio?). Left from the 32Kx8 SRAM, however, is J0705, a connector labeled with 'SAX' in the service manual and 'AMP' imprinted to it (purpose unknown) |
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| The AT&T MMU+ 1114D is used as the IPX's memory management unit. Details about its exact functions in the SPARC-design are unknown (well, at least to me) |
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| AT&T RAM+. Purpose of that is unknown - perhaps it provides logic for RAM address multiplexing, in combination with additional 64 MB offboard- (SBus-) RAM. Any ideas? |
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| Here the machine's RAM bank, four 72-pin sockets for PS/2 SIMMs with parity ('33/ 36 bit' - meaning that these RAMs have 4 bits for parity, but Sun-4c uses only one). Generally, memory may be organized as 1Mx33/36 or 4Mx33/36, and the PS/2 SIMMs are referred to as 'DSIMMs' in Sun's service manuals. The SPARCstation IPX can have 64MB onboard RAM (using 4 pcs. 4Mx33/36) and 64MB offboard RAM (using a Sun SBus RAM expansion). Here you can see one 4Mx33 DSIMM (Sun part.no. 501-1822) in bank 0 |
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| 525-1177-06 is an 256Kx8 'OpenBoot PROM', and contains OpenBoot 2.90 version 20. It provides basic functions for powering up and testing the machine (bootstrap code, power-on tests etc), and advanced functions for peripheral configuration and diagnostics (e.g. SBus- and SCSI-devices, RAM). Configuration is done with a variant of the Forth language (the so-called 'Forth Toolkit'), and all parameters are then permanently stored in the NVRAM (nonvolatile RAM, behind the PROM). Interesting to know that the IDPROM,
which was a separate ROM in older Sun workstations and contained host-ID, MAC-address and other machine-specific information, is now part of the OpenBoot PROM |
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| Closeup on the machine's Sun type 5 keyboard. As already mentioned, earlier Sun-4 machines came with the appropriate Sun type 4 keyboard, which had a different layout. I assume that early IPX still came with a type 4 keyboard as well. However, since type 5 keyboards identify themselves as type 4, you could use both types of keyboards |
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| The GX-graphics controller, a 2D graphics accelerator, is the heart of the cgsix framebuffer which is integrated on the IPX's board. Compared to the various cgsix SBus-variants, the IPX's onboard-cgsix has two additional resolutions, 1022x1000 @76Hz and 1024x800 @85Hz. Also notable is that this specific cgsix can't be used with ECL monochrome monitors |
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| The Brooktree Bt458LPJ135 is the cgsix framebuffer's RAMDAC, producing the actual output. 'PJ135' means that it operates at 135 MHz and comes in plastic J-lead packaging (which is a form of PLCC). The Bt458 can output up to 1280x1024 pixels in 8 bit depth, plus 2 bit overlay information (in the SPARCstation IPX, however, output is limited to 1152x900 because the GX-controller can map a maximum of 1 MB RAM as framebuffer). The Bt458 is a triple-channel version of the single-channel Bt457, which was often used for monochrome framebuffers.
Left from the Bt458, by the way, a Motorola 10H116, which is an ECL line receiver |
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| These 8 pcs. MT42C8128DJ-10 (2Kx8 SRAMs) provide the Bt458 with 16 KB video RAM. This RAM is used to buffer the current RAMDAC output (meaning the actually outputted frame). However, it doesn't contain any color palette information (the Bt458 has onchip color RAM for that purpose). This RAMDAC buffer has to be refreshed with data from the framebuffer RAM frequently to provide a constant output (how often depends on vertical and horizontal frequencies used, of course) |
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| Also an interesting part of the Sun 4c architecture is audio. For a cheap and simple solution, Sun decided to use AMD's AM79C30A-series ISDN controller chips for sound (since they can sample at 8KHz for telephony anyway). However, because of their 'telephony-roots', the 79C30A can only process single-channel audio (=monaural), and only bit-by-bit (and thus are very slow). But in my opinion, that's by far enough for a workstation or server |
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| The NCR 53C90A is the IPX's Fast SCSI-2 controller. The 53C90A were popular (and relatively cheap) single-bus SCSI-controllers, and thus used in many other designs as well. But they were not capable of busmastering and needed to interrupt the CPU for data transfers. Besides the 53C90A, by the way, there was also the 53C90B which additionally featured parity data transfers |
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| The Intel N82072 is a standard floppy-controller, which was also used in the IBM AT design, and many others. It's compatible with the NEC µPD765 (often found in XTs) and the Intel 82077 (used in IBM PS/2 series, for example). It can control up to four FM/MFM floppy drives (with up to 1 MBit/s data rate each) and supports DMA access |
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| These two AMD AM85C30-8JC are used for RS232/ RS423 serial I/O, and most likely also for triggering keyboard and mouse operations. Such an AM85C30 contains all functions needed for serial communication, such as two-channel full-duplex operation, synchronous/ asynchronous transfer-modes with up to 1 MBit/s and baud-rate generator. According to AMD's datasheet the 85C30 was originally created for 8/ 16 bit designs and contains some special features for operation with Intel 8086 or Motorola 68000-class CPUs. Another interesting thing is its capability of manchester decoding (for ethernet),
since it is unused in the IPX (done via the AM7992 instead) |
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| The UC5170CQ and UC5180CQ are serial port line driver (UC5710CQ) and serial port line receiver (UC5180CQ). As implied by the name, they handle communication with serial devices, which can be either RS232- or RS423-compliant. Which standard is used for the SPARCstation's serial ports is determined via jumpers J0502 and J0503 (right): |
| J0502 | J0503 | Mode |
| 1-2 |
1-2 | RS423 (default) |
| 2-3 | 2-3 | RS232 |
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| AMD's so-called 'Lance'-chipset for ethernet. It consists of an AM7990JC/80 (DMA-controller) and AM7992BJC SIA (serial interface adaptor). Optionally, there can be an AM7996 (transceiver), when 10base2-compatibility is required (not in the IPX). Additional to the DMA-controller mentioned earlier, the AM7990JC/80 also contains 48 Bytes FIFO buffer. It controls the AM7992BJC, which is responsible for collision detection, manchester encoding/ decoding and forwarding serial data to the machine's AUI-connector (for external transceiver) |
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| The AT&T 1119A's purpose in the SPARCstation-design is unknown. Since it resides directly behind the NCR 53C90, it could be the machine's DMA controller |
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| This '13W3'-called monitor-connector (with specially isolated R, G and B-pins) is an established standard in the world of workstations |