{"id":1552,"date":"2017-01-08T11:53:12","date_gmt":"2017-01-08T11:53:12","guid":{"rendered":"http:\/\/avitech.com.au\/?page_id=1552"},"modified":"2017-01-10T21:28:45","modified_gmt":"2017-01-10T21:28:45","slug":"vaxmate","status":"publish","type":"page","link":"https:\/\/avitech.com.au\/?page_id=1552","title":{"rendered":"VAXmate"},"content":{"rendered":"\n\n\n\n\n\n\n\n
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The VAXmate is an IBM PC\/AT compatible personal computer produced by DEC.<\/p>\n

Its claim to fame is that it is the world’s first commercially produced diskless (ie net-booting) personal computer, as discussed on on the VAXmate’s Wikipedia<\/a> and Microsoft<\/a> webpages. But it can also be used as a standalone conventional PC.<\/p>\n

Despite its name, the VAXmate is not a VAX and there is no VAX architecture in the VAXmate.<\/p>\n

Rather, the VAXmate is an x86-based monochrome PC. The unit with the CRT in it houses the power supply, computer board, monochrome CRT and 1.2MB 5.25″ floppy drive.<\/p>\n

The vertical door on the right side of the CRT hides the floppy drive. Open the door and the recessed floppy drive becomes accessible.<\/p>\n

On the back panel you will find the power connector, power switch, BNC Ethernet jack, DB25M serial port and an MMJ socket for a printer. On the side panel there are connectors for the LK250-AA keyboard and the round VSXXX-AA “puck” mouse. Note the keyboard connector is not the standard DEC 4-pin arrangement found on keyboards intended for VT-series terminals (such as the LK201 keyboard). Instead, this is a larger rectangular plug that has a strain relief catch on each side of the plug. The mouse socket appears to be a standard PS\/2 plug, but I have not verified this.<\/p>\n

My collection did include 7 VAXmates as well as manuals and original DEC software. Most of this has been re-homed with Nigel at Retro Computing Tasmania. I have kept one working VAXmate in my collection.<\/p>\n<\/td>\n<\/tr>\n

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Inside the VAXmate<\/h4>\n

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Opening the rear panel of the VAXmate is easy. Just unplug the power cable, and you will see a tab at the lower edge of the power connector. Press this downwards, and the rear panel will fall open. This gives you access to the PCB just inside the rear door.<\/p>\n

Getting the entire upper case assembly off is not so easy. I used the brute force method (on a VAXmate that was being scrapped) but that resulted in knurled nuts permanently separating from their plastic housing. So I don’t recommend that technique. It appears the proper technique is to open the rear panel, then remove the two screws that you will see in the bottom left and bottom right corners. The problem is that the rear door only opens to 45 degrees, and this obstructs access to the screws. You will need to investigate this a little further, if you want to remove the upper case.<\/p>\n<\/td>\n<\/tr>\n

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Expansion base<\/h4>\n

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The VAXmate can be clipped on to an optional pizza-box style base unit (the base unit is shown in the photo on the right) that houses a second power supply, 3-slot ISA expansion backplane, Western Digital ISA MFM hard drive controller and a Seagate ST-225 20MB MFM hard drive.<\/p>\n

To remove the VAXmate from its base, simply unclip the 3 latches (one on each side, and one at the rear). The VAXmate then lifts off the base. No fasteners need to be removed or loosened.<\/p>\n

A word of caution here: When you remove the VAXmate, the 4 rubber feet on the bottom of it are almost certainly now in liquid form. It is messy stuff and difficult to clean up. So as soon as you remove the VAXmate from its expansion base, I suggest you place the VAXmate on its side, and take care of removing what is left of the decomposed feet. It you sit it down on carpet, you can expect a very time-consuming clean up task!<\/p>\n<\/td>\n<\/tr>\n

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Once the VAXmate has been removed from the base, the base can be opened by unclipping just one latch. Again, no fasteners need to be loosened or removed. Once the lid has been removed, the content are easily accessible. The 3-slot ISA backplane tilts up without removing any fasteners.<\/p>\n

The ISA backplane accommodates the WD1003-WAH MFM controller board (which has no rear-panel mounting bracket) plus up to two additional ISA cards. There is only space for one half-height MFM drive in the expansion unit.<\/p>\n

Under the beige cap shown at the top of the photo is a battery pack. I’m not sure what this is for. It is wired into the ISA backplane.<\/p>\n<\/td>\n<\/tr>\n

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Software<\/h4>\n

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The boot screen shows that my VAXmate is running a DEC-modified version of MSDOS 3.10.<\/p>\n

There is not much installed on this machine. A screenshot from XTreePro (see below) shows the directory structure. It also shows there are only 290 files on the hard drive!<\/p>\n

Here’s a list of the software that is installed on the hard drive:<\/p>\n

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Health of the MFM hard drive<\/h4>\n

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I booted SpinRite II from the floppy drive and ran the “Quick Surface Scan” test. This takes about 60 minutes to execute. The results screen is shown on the right.<\/p>\n

The results don’t look all that good. I don’t have a manual handy to fully decode the results screen, but there seems to be a large number of “correctable” and “uncorrectable” errors. Fortunately most of the errors are on tracks that are not in use.<\/p>\n<\/td>\n<\/tr>\n

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Some observations<\/h4>\n

I’ve not spent very much time on this machine yet. I have noticed the following though:<\/p>\n