DECpc 325
.jpg) | |
| DECpc 325sxLP system unit, keyboard and monitor (David Hall, zx.net.nz) | |
| Specifications | |
|---|---|
| Manufacturer | Digital Equipment Corporation |
| Type | Desktop personal computer (low-profile) |
| Released | April 1992[1] |
| CPU | 80386SX at 25 MHz (AMD part in DEC's specification)[2][3] |
| Memory | 2 MB standard; 9-bit parity SIMMs, up to 32 MB supported[3] |
| Storage | 3.5-inch 1.44 MB diskette drive; IDE fixed disk[2][4] |
| Display | Oak OTI-067 VGA on the system board[4] |
| Sound | — |
| Power | 115 W maximum; 110–120 V or 220–240 V AC[2] |
| Dimensions | 410 × 396 × 90 mm[2] |
| Weight | 7.75 kg (system unit)[2] |
| OS / Firmware | MS-DOS 5.0 and Windows 3.0[1] |
| Model no. | DECpc 325sxLP (PC731) |
The DECpc 325 is a low-profile desktop PC sold by Digital Equipment Corporation (DEC) from April 1992. Its front badge reads DECpc 325sxLP, and DEC documented it together with the 20 MHz DECpc 320sxLP in one user's guide and one technical reference manual.[1][5] DEC's utilities diskette for it is labelled "DECpc 325 User Disk".[6]
History
[edit | edit source]David Hall's account of the machine records that it was built in DEC's Taiwan facility, introduced in April 1992 with MS-DOS 5.0 and Windows 3.0, and advertised in Singapore and reported in Australia that month. He found no evidence of sales outside the Asia-Pacific region. DEC later used the name DECpc 325sxLP again for a different machine in its August 1992 DECpc LP range, with Cirrus Logic graphics in place of the Oak chip.[1] DEC's EK-DECSX manuals, the DECpc 325 User Disk and the DECpc 320/325 video driver disk all belong to the April 1992 machine with Oak graphics.[7]
Hardware
[edit | edit source]| Item | Specification |
|---|---|
| CPU | 80386SX, 20 MHz (320sxLP) or 25 MHz (325sxLP) |
| ISA bus speed | 6.67, 8 or 10 MHz |
| Memory | 2 MB standard, 9-bit SIMMs, 80 ns or faster, byte parity; options 4 to 32 MB |
| ROM BIOS | 64 KB, Phoenix |
| Battery | 3-year shelf life |
| Board size | 8.657 × 13 inches, 4 layers |
DEC's user's guide lists the 320sxLP with an Intel 80386SX at 20 MHz and the 325sxLP with an AMD 80386SX at 25 MHz; Hall gives the CPU in his machines as an Intel 386SX or AMD Am386SX at 25 MHz.[2][1] The system board uses the Chips and Technologies 82C386SX chip set (82C320 system controller and 82C331 ISA bus controller), an 82C712 peripheral controller for the serial, parallel, IDE and floppy interfaces, and Oak's OTI-067 VGA controller with the OTI-066 DAC and OTI-069 clock generator.[4] Hall gives the video memory as 512 KB and the expansion as three 16-bit ISA slots.[1]
The front panel has a power button, CPU reset button, diskette eject button, and power, fixed disk, turbo and diskette activity indicators. At the rear are an auxiliary AC outlet for the monitor, the video, parallel and serial ports, keyboard and PS/2 mouse connectors, and the power inlet.[8] DEC warns never to stand the system unit on its side.[8]
The power supply is rated 115 W maximum and runs from 110–120 V at 60 Hz or 220–240 V at 50/60 Hz.[2] Its power switch is inside the supply, worked from the front button through a linkage.[1]
Known faults
[edit | edit source]- The CMOS battery, a Rayovac 840 4.5 V alkaline pack held to the system board with Velcro, leaks and corrodes the board. See DECpc 325 General Maintenance.[1]
- The rubber sleeve that joins the front power button linkage to the switch in the supply perishes, so the button stops working.[1]
- Hall found the tantalum capacitor C3 on a riser board blown, in September 2021.[1]
See DECpc 325 Troubleshooting Guide for DEC's error messages, beep codes and fault tables.
Documentation
[edit | edit source]- DECpc 320sxLP/325sxLP User's Guide, EK-DECSX-UG.003, June 1992: File:DECpc 320sxLP 325sxLP User's Guide (EK-DECSX-UG.003).pdf
- DECpc 320sxLP/325sxLP Technical Reference Manual, EK-DECSX-TM-001, March 1992: File:DECpc 320sxLP 325sxLP Technical Reference Manual (EK-DECSX-TM-001).pdf. The scan ends in chapter 6, before the power supply chapter.[9]
Related pages
[edit | edit source]- DECpc 325 General Maintenance
- DECpc 325 Troubleshooting Guide
- DECpc 325 Documentation
- DECpc 320P
- DECpc 325P
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 David Hall, "Digital DECpc 320sxLP/325sxLP", zxnet, last modified 31 May 2024, zx.net.nz. Collector's notes on two machines: origin, dates, specifications, battery, power switch linkage, memory, riser capacitor failures.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 DEC, DECpc 320sxLP/325sxLP User's Guide, EK-DECSX-UG.003, pp. 8-1 to 8-2. System unit specifications.
- ↑ 3.0 3.1 3.2 DEC, DECpc 320sxLP/325sxLP Technical Reference Manual, EK-DECSX-TM-001, p. 2-2, Table 2-1, "System Board Specifications".
- ↑ 4.0 4.1 4.2 DEC, DECpc 320sxLP/325sxLP Technical Reference Manual, EK-DECSX-TM-001, contents and pp. 3-3 to 3-5. System board features and chip set.
- ↑ Digital Equipment Corporation, DECpc 320sxLP/325sxLP User's Guide, EK-DECSX-UG.003, June 1992 (File:DECpc 320sxLP 325sxLP User's Guide (EK-DECSX-UG.003).pdf).
- ↑ "DECpc 325 User Disk", version 1.00, disk image and label photograph, archive.org.
- ↑ "DECpc 320/325 Enhanced Video Drivers", revision 2.0, disk image, label photograph and README files for the Oak OAK8640 Windows drivers, archive.org.
- ↑ 8.0 8.1 DEC, DECpc 320sxLP/325sxLP User's Guide, EK-DECSX-UG.003, pp. 3-3 to 3-5. Rear and front panels; caution on standing the unit on its side.
- ↑ Digital Equipment Corporation, DECpc 320sxLP/325sxLP Technical Reference Manual, EK-DECSX-TM-001, March 1992 (File:DECpc 320sxLP 325sxLP Technical Reference Manual (EK-DECSX-TM-001).pdf).