Revision 7 as of 2021-07-29 23:05:53

Clear message

UCC has a S-100 Alpha Micro system which [FVP] is working on restoring back to working order (as of July 2021).

For more UCC-specific history of Murphy, please see: ProjectWhatIsThat/Murphy, https://www.ucc.asn.au/machines/murphy.ucc

Amazingly there is quite a significant amount of online resources (including extensive scanned documentation) for just about everything Murphy related. See the list below for details and links.

What bits are there

  • ACP "Alpha16" wooden box computer case
  • an unregulated 250V transformer-rectifier-capacitor style +8V/-8V/+16V power supply (built into the wooden case) - suspected working
  • Electronic Control Technology MB-10 10 slot S-100 backplane (copyright 1977) - suspected working
  • Power-One CP272A switchmode DC power supply - outputs are +5V @ 2.2A, -5V @ 0.2A, +24V @ 1.2A, +8V @ 10A (surge, unregulated) - for Persci drives - not working
    • tested with power on with no load - output voltages were correct (initial test before explosions)
    • tested with drive connected - catastrophic failure involving multiple component explosions - need replacement components
  • Persci 277 dual 8" single-sided voice-coil-actuated double-density floppy drive - not working Installation & Maintenance Manual Logic & Schematic diagrams

    • tested with "working" original PSU - multiple PCB components exploded simultaneously, need some replacement parts & more testing

  • Mitsubishi M2896 Rev.G 8" floppy drive S/N G3942001 (loose in box) - suspected to be a random leftover part from some other computer build (dated 1984) - untested
  • ACP Terminal (builtin monitor + keyboard combo) - suspected not working (tested in 2019? - white dot on screen or no display at all)

S-100 Cards

  • Alpha Microsystems AM-100 16-bit CPU (set of 2 cards) (1977) - untested Tech Manual Instruction Set Ref

  • Alpha Microsystems AM-200 Floppy Disk Controller Rev B (1977) - untested Tech Ref(?)

  • Alpha Microsystems AM-300 6 channel Serial IO board (1977) - untested Mixed Docs + Schematics Technical Manual

  • 4 * Industrial Micro Systems IMS C00282 16K Static RAM Memory boards (1977) - untested Manual

  • Australian Computer Products diagnostic board(?) - no part number, includes an enlarged UV mask which probably was used to design/manufacture the PCB itself

Disk Drives

At some point it would be nice to run the 8" Persci drive using a Greaseweazle to try reading data off the club's box of 8" floppy disks. Assuming the drive unit itself can ever be restored to (somewhat) working order, the Greaseweazle should be able to control it with some custom wiring or something like the FDADAP to connect the standard 34-pin PC floppy cable signals to the Persci 277's 50-pin connector.

Persci 277 repair notes

The drive has 4 main PCBs which are connected by a whole range of cables. The largest board covers almost an entire side of the drive and amazingly can be swung open using a hinge (after removing two screws). When testing powering up the drive with the original PSU, a few components failed in a rather dramatic way - sound, smoke and flames - which hopefully only need replacing, and didn't cause too much damage to the rest of the circuitry. Everything seems to be fairly discrete logic, there aren't any surface mount components to be seen in the entire assembly, and the schematic reference contains detailed circuit diagrams of the whole drive.

Photos

Here are some photos taken of various bits and pieces. Order is left-to-right, top-to-bottom.

Persci 277 drive (rear), side-view, side-view with PCB lifted up, other side view, drive protection transport card

Persci277-rear.jpg Persci277-side.jpg Persci277-internal.jpg Persci277-otherside.jpg Persci277-card.jpg

ACP S-100 backplane + underside, original S-100 PSU, Disk drive PSU (CP272A)

ACP-backplane.jpg ACP-backplane-underside.jpg ACP-PSU.jpg CP272A-PSU.jpg

AM-100 CPU board 1, AM-100 CPU board 2, AM-200 FDC board, AM-300 Serial IO board, IMS 16K RAM board (matte IC variant), IMS 16K board (gloss variant), ACP diagnostics board

AM-100-1.jpg AM-100-2.jpg AM-200.jpg AM-300.jpg IMS-16K-33007.jpg IMS-16K-33046.jpg ACP-diag-board.jpg

M2896 Disk drive (label only)

M2896-label.jpg

Resources & References

There are some really good websites out there with information & documentation for most if not all of these ancient computer bits. The documents uploaded above came from a mix of these sites.

Note: this was basically a dump of my browser session when writing this page. Not very well organised but here it is.


CategoryProjectsActive