Editing DECpc 433

{{Infobox computer
| name         = DECpc 433 Workstation
| image        = [[File:DECpc 433 Workstation with SCSI expansion box (bitsavers).jpg|260px|frameless]]
| caption      = DECpc 433 Workstation with the SCSI expansion box on top (bitsavers.org)
| manufacturer = Digital Equipment Corporation; system board co-designed and built by Intel
| type         = Desktop personal computer (graphics workstation)
| price        = US$5,999 (diskless configuration, 1991)<ref name="pcmag" />
| cpu          = Intel 486 at 33 MHz<ref name="trm1" />
| memory       = 8 MB standard; 4 to 48 MB in 80 ns 9-bit SIMMs<ref name="trma" />
| storage      = Two 3.5-inch bays (1.44 MB diskette or IDE disk) and a 2.5-inch IDE bay; SCSI connector for the expansion box<ref name="sg1" />
| display      = Intelligent graphics controller (TMS34020), 1280 × 1024 on DEC fixed-frequency monitors<ref name="pcmag" /><ref name="trm10" />
| power        = 105 W power supply<ref name="sg1" />
| dimensions   = 2.75 × 14.5 × 16.5 in<ref name="pcmag" />
| os           = MS-DOS, OS/2 (DEC supplemental kits)<ref name="sg2" />
| model        = PCW10 (Ethernet or Token Ring system board)
}}
The '''DECpc 433 Workstation''' is an Intel 486 personal computer sold by Digital Equipment Corporation in 1991 as a PC-compatible graphics workstation. Its system board was co-designed and built by Intel, and its graphics card, built by Appian Technologies around the Texas Instruments TMS34020 graphics processor, drives DEC's fixed-frequency workstation monitors at 1280 × 1024.<ref name="pcmag" /> DEC's service guide for it is dated June 1991.<ref name="sg" />

== History ==
''PC Magazine'' reviewed the DECpc 433 in its issue of 15 October 1991, listing it at US$5,999 as a diskless network node, with DEC's 20-inch 1280 × 1024 monitor at US$1,995 and the expansion box at US$450.<ref name="pcmag" /> DEC offered it with Pathworks networking; the system board came in Ethernet and Token Ring versions.<ref name="pcmag" /><ref name="trm1" /> The rear label of a surviving unit reads Model PCW10-A2, Made in U.S.A.<ref name="bitsavers" />

== Hardware ==
The system board carries the 33 MHz Intel 486, the 82340DX ISA chip set, three banks of four SIMM sockets, a socket for an optional 64 KB or 128 KB external cache module, two 9-pin serial ports, a parallel port, an SCSI connector, floppy and IDE interfaces, the LAN interface and its connectors, keyboard and mouse connectors and four status LEDs.<ref name="trm1" /><ref name="sg1" /> The base system shipped with 8 MB in eight 1 MB × 9 SIMMs; 1 MB × 9 and 4 MB × 9 modules can be mixed between banks but not within one, and must be 80 ns or faster.<ref name="sg1" /> DEC's technical reference lists 114 bytes of battery-backed RAM and a six-layer, 10.5 × 12 inch board.<ref name="trma" />

The intelligent graphics controller occupies the one 16-bit ISA slot. It has four SIMM sockets of its own for 1 MB or 4 MB SIMMs of application memory.<ref name="sg1" /><ref name="trm1" /> ''PC Magazine'' gives it 2 MB of video RAM and either 4 MB or 16 MB of application memory.<ref name="pcmag" />

The 105 W power supply feeds the board and the 3.5-inch drives; the 2.5-inch IDE disk takes its power from the board.<ref name="sg1" /> The optional SCSI expansion box holds up to three SCSI devices on its own 63 W supply.<ref name="sg1" />

<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table" style="width:100%; text-align:center;"
|+ '''105 W power supply outputs (DEC Table 11-1)'''
! Output !! Continuous current !! Peak for 15 s !! Maximum power
|-
| +5 V ±5% || 3.5 to 18.0 A || – || 90 W
|-
| +12 V ±5% || 0 to 1.0 A || 2.0 A || 12 W
|-
| −12 V ±10% || 0 to 0.2 A || – || 2.4 W
|-
| −5 V ±10% || 0 to 0.2 A || – || 1 W
|}
<ref name="trm11" />

The supply senses the mains and runs from 90–132 V or 180–264 V, 47–63 Hz.<ref name="trm11" /><ref name="sga" />

== Known faults ==
* Clock battery leakage. The clock battery is a 4.5 V alkaline pack (DEC part 29-28951-01) held on a Velcro pad against the inside of the front panel and plugged into header J8.<ref name="sg3" /><ref name="sg3b" /> On a surviving machine photographed for bitsavers the pack is a Duracell MN1500CCB "Alkaline Computer Clock Battery", and the chassis metal above it is rusted.<ref name="bitsavers" /> See [[DECpc 433 General Maintenance]].
* No picture. DEC's fault tables put a wrong setting of the video select switch first among the causes of a blank or garbled screen.<ref name="sg2t" /> On the rear panel it is a rotary switch numbered 1 to 14 beside the video connector.<ref name="bitsavers" />
See [[DECpc 433 Troubleshooting Guide]] for POST messages and beep codes.

== Documentation ==
* ''DECpc 433 Workstation Service Guide'', ER-PCW10-SV-001, June 1991: [[:File:DECpc 433 Workstation Service Guide (ER-PCW10-SV-001).pdf]]
* ''DECpc 433 Workstation Technical Reference Manual'', ER-PCW1A-TR, December 1991: [[:File:DECpc 433 Workstation Technical Reference Manual (ER-PCW1A-TR).pdf]]
Details are on [[DECpc 433 Documentation]].

== Gallery ==
<gallery mode="packed" heights="200">
File:DECpc 433 Workstation interior (bitsavers).jpg|Inside a DECpc 433, with the clock battery against the front panel at upper left (bitsavers.org)
File:DECpc 433 alkaline clock battery and corrosion (bitsavers).jpg|The alkaline clock battery and rusted chassis above it (bitsavers.org)
File:DECpc 433 Workstation rear panel (bitsavers).jpg|Rear panel with the video select switch beside the video connector (bitsavers.org)
</gallery>

== Related pages ==
* [[DECpc 433 General Maintenance]]
* [[DECpc 433 Troubleshooting Guide]]
* [[DECpc 433 Documentation]]
* [[DECpc 325]]
* [[DECpc LP]]

== References ==
<references>
<ref name="pcmag">Nate Zelnick, "DECpc 433: Fast Video Blurs the Distinction Between PC and Workstation", ''PC Magazine'', 15 October 1991, pp. 48–49, scan at [http://bitsavers.org/pdf/dec/decpc/DECpc_433/ bitsavers.org] (ann_1_199110.jpg and ann_2_199110.jpg). Price, Intel and Appian roles, graphics memory, monitor prices, case size.</ref>
<ref name="sg">Digital Equipment Corporation, ''DECpc 433 Workstation Service Guide'', ER-PCW10-SV-001, June 1991 ([[:File:DECpc 433 Workstation Service Guide (ER-PCW10-SV-001).pdf]]).</ref>
<ref name="sg1">DEC, ER-PCW10-SV-001, pp. 1-3 to 1-5. System box FRUs, SIMMs, external cache, power supply, drives, graphics controller, battery, SCSI expansion box.</ref>
<ref name="sg2">DEC, ER-PCW10-SV-001, pp. 2-1 to 2-2, Table 2-1. MS-DOS and MS OS/2 supplemental kits.</ref>
<ref name="sg2t">DEC, ER-PCW10-SV-001, pp. 2-16 and 2-19, Tables 2-6 and 2-8.</ref>
<ref name="sg3">DEC, ER-PCW10-SV-001, pp. 3-1 to 3-2, Table 3-1. FRU part numbers including the 4.5 V battery 29-28951-01.</ref>
<ref name="sg3b">DEC, ER-PCW10-SV-001, pp. 3-23 to 3-24. Removing and replacing the system battery.</ref>
<ref name="sga">DEC, ER-PCW10-SV-001, p. A-1, Table A-1. Input voltage ranges and current.</ref>
<ref name="trm1">Digital Equipment Corporation, ''DECpc 433 Workstation Technical Reference Manual'', ER-PCW1A-TR, December 1991, pp. 1-3 to 1-4 ([[:File:DECpc 433 Workstation Technical Reference Manual (ER-PCW1A-TR).pdf]]). System board features, Ethernet and Token Ring boards, 33 MHz i486.</ref>
<ref name="trm10">DEC, ER-PCW1A-TR, chapter 10. Intelligent graphics controller and the TMS34020 graphics system processor.</ref>
<ref name="trm11">DEC, ER-PCW1A-TR, p. 11-1, Table 11-1. 105 W power supply specification and automatic input range.</ref>
<ref name="trma">DEC, ER-PCW1A-TR, p. A-2, Table A-1. Memory sizes and speed, battery, non-volatile RAM, board size and layers.</ref>
<ref name="bitsavers">Photographs of DECpc 433 Workstation serial number 2B21100274 and of the rear label PCW10-A2, [http://bitsavers.org/pdf/dec/decpc/DECpc_433/ bitsavers.org/pdf/dec/decpc/DECpc_433/].</ref>
</references>

[[Category:Digital Equipment Corporation]]