Here are some pictures of the MAI Basic Four 510 that i got in the second quarter of 2014 from Holger. I picked up the machine in Germany. Equipped with 2 external drives (Century Data T80), a parallel printer, 3 terminals and a lot of disk packs it would not fit into my small car. However, i worked in the area where the machine was located so i picked up some parts at the end of each week for 3 weeks in a row.

Serial is 510-07254, equipped with 96K memory, a 8 way controller (3 ports are routed to db 25 connectors), parallel port, and according to config sheet, BOSS 4.3B.
There is one disk pack labeled "BOSS", i have to try if that one will boot.

The main (5 Amps) fuse was blown while we tried to power up the cpu (blowed after 2 minutes), i have to check that when i have the machine in my shop.

The manuals that came with the machine are already on bitsavers.org/mai, however, i have no diag software nor do i have the service manual and the CPU reference manual.

• M8001XX System 610/730 Service Manual
• 1300 CPU Technical Manual
• M1300 Series CPU Organisation and Description Reference Manual
• M80651A System 1350 Service Manual, Vol I
• M80652A System 1350 Service Manual, Vol II
• M80781A System 1600 Service Manual, Vol I
• M80782A System 1600 Service Manual, Vol II

In the meantime i have done some checks. The PSU is running fine now and the CPU board runs the simple test program typed in via console boot. The io address of the serial port (Thanks Folkert) is different than the one for the 210 but at least the test runs.

This is the CPU (left) containing the main CPU and the disk controller and one of two existing 80 MB drives. Larger picures are avaible by clicking on the picture.

One of the Centrury Data T80 drives. These ones are really heavy.

This is the power supply of the 510. Have not yet picked up the machine, however, the 5 Ams fuse was blown after about 2 minutes of operation. Dont know if this PSU is a switching one or a linear regulated one like in the original microdata. The original one is based on a LM 709 with a heater build with five 2N3055 for the 5V supply, will see later.

The upper cage contains the cpu boards (the one with the four switches), memory, parallel printer interface, 8 way controller (the one with the 3 round gray cables) and an interface to the disk controller.
The disk controller is located in the lower cage, According to the , the controller contains a cpu and a formatter board. The cpu may deliver some higher level functions like key search. (To be verified)