DECmate II Documentation
DECmate II Documentation describes the Digital Equipment Corporation documents for the DECmate II held as PDFs here, with the reverse-engineered schematic of its power supply.
DECmate II Owner's Manual (EK-DECM2-OM-001)
[edit | edit source]The DECmate II Owner's Manual is DEC's 123-page user manual, part number EK-DECM2-OM-001, 1st edition, December 1982.[1]
Contents: Part 1, Overview (chapter 1, description of the system); Part 2, Getting Started (chapters 2 to 6: preparing for the DECmate II, attaching options, keyboard, diskettes, turning on); Part 3, Solving Problems (chapter 7, What to Do If Your DECmate II Doesn't Work, with the self-test messages, Table 7-1 Self-Test Error Codes on p. 78, routine measures, power problems and the System Test diskette); Part 4, Accessories and Supplies (chapter 8); an appendix of specifications (pp. 93 to 96).[1]
It has no circuit information. DEC sold a separate DECmate II Repair Guide (EK-DECM2-AM) with detailed troubleshooting and module replacement procedures, and a DECmate II Technical Description (EK-DECM2-TD).[1] The hosted copy was converted to 150 dpi greyscale from the archive.org scan.
Download: DECmate II Owner's Manual (EK-DECM2-OM-001).pdf
PC278 DECmate II print set (MP-01492-00)
[edit | edit source]DEC's PC278 print set, MP-01492-00, 60 pages.[2]
Contents: the PC278 unit assembly and parts list, including the BA25 system unit with the H7842-A supply and RX50-AA drive; the 54-15426 system board parts list (sheets A1 to A5, in two revisions), assembly drawing and 16-sheet schematic; the BA25 small system unit enclosure drawings and parts list.[2]
It does not include the H7842 power supply schematic, the RX50 drive or the VR201 monitor.
Download: DECmate II PC278 Print Set (MP01492-00).pdf
H7842 power supply schematic (Tony Duell)
[edit | edit source]A hand-drawn schematic of the H7842 supply, six A4 sheets, reverse-engineered by Tony Duell and distributed through bitsavers.[3] The PDF holds a wiring drawing of the supply, fan and switch in the Rainbow, three PSU sheets (sheet 1 the mains rectifier, start-up supply and output connectors; sheet 2 the chopper and its driver; sheet 3 the DC outputs, crowbar and −12 V regulator) and two control module sheets. It gives component values but no voltage ratings. One repairer reports that two sections of comparator E3 appear to be mislabelled.[4]
Download: DEC H7842 Power Supply Schematic (Tony Duell).pdf
Other documents
[edit | edit source]- DEC's DECmate II Specification (revision 4, January 1983) is a text file on bitsavers: a specification written during development, covering physical and electrical data, the comparison with the DECmate I, the RX50 controller and the ROM.[5]
- The VR201 monitor print set is described on DECmate III Documentation.
- The H7842 supply is documented in chapter 7 of DEC's Rainbow 100 Technical Manual (EK-PC100-TM-001), on bitsavers.[6]
- An image of the System Test diskette, BL-T345B-MA, is on archive.org.[7]
Pages that cite these documents
[edit | edit source]- DECmate II – specifications and hardware
- DECmate II General Maintenance – environment, cleaning, module removal
- DECmate II Troubleshooting Guide – self-test codes, routine checks
- DECmate II Power Supply Service – H7842 values and repair
References
[edit | edit source]- ↑ 1.0 1.1 1.2 Digital Equipment Corporation, DECmate II Owner's Manual, EK-DECM2-OM-001, December 1982, contents and preface. Source: archive.org.
- ↑ 2.0 2.1 Digital Equipment Corporation, PC278 DECmate II print set, MP-01492-00. Source: bitsavers.org.
- ↑ Tony Duell, H7842 power supply schematic. Source: bitsavers.org.
- ↑ Rob Jarratt, "DEC Rainbow H7842 Power Supply Failure", Rob's Old Computers, 20 November 2022, robs-old-computers.com.
- ↑ Digital Equipment Corporation, DECmate II Specification, revision 4, 18 January 1983, bitsavers.org.
- ↑ Digital Equipment Corporation, Rainbow 100 Technical Manual, EK-PC100-TM-001, May 1984, bitsavers.org.
- ↑ "DECmate II System Test Diskette", BL-T345B-MA, archive.org.