I was fortunate to pick up an uncommon upgrade for the pizza-box Macs: A DGR Max Expansion. This is similar to the MicroMac Power Workstation and the MicroQue LC Top Hat. It consists of a metal chassis that fits between the top and bottom of a stock LC case.
The rear includes a second power supply switch and cord receptacle. There are four punchouts for PDS cards with external connectors. On the far right, there are four switches for enabling/disabling up to four PDS cards.
Below shows the interior with the PDS expansion board with all of the PDS cards removed).
The second power supply sits on a little shelf.
The power supply is a Golden Power Systems Ultratek Devices GP1037 with +5V@5A, +12V@1A, and [email protected] for 38 watts total.
Looking from the rear, towards to the front, notice that the floppy drive has been moved up to a shelf to align with the original LC top cover. Underneath the shelf is empty space, plus the usual location for a hard drive.
Atop the shelf above the original hard drive is space for a second hard drive. The SCSI cable has been swapped to accommodate two hard drives. A second power supply connector (for the second hard drive) is located on the DGR PDS adapter board.
The DGR PDS Adapter board features connectors for the PDS slot switches, power supply, second hard drive, and an accelerator/cache card adapter. Although there are four slots, the LC won't support their simultaneous use, with the exception of an accelerator cache card. Take note of the four IC chips at the top of the image. They each have a different color sticker, which likely indicates they are programmed differently. (Oddly, the blue dot IC is oriented in the opposite direction).
The ICs are 18CV8 electrically erasable logic chips.
The revision of this board (1994 A3) is newer than others I've seen posted.
Here is a shot of the resistor packs.
Presumably, the logic chips enable/disable the individual PDS cards. There is a header for the rear switches on the adapter board. J5 is has a pin cut off for keying purposes. The pin below it is not attached to anything on the cable.
Nothing fancy about the switch wiring. (The two loose wires broke of in shipping. They belong to the bottom switch.)
This computer came with a DayStar accelerator and a DayStar LC adapter. The green board in the middle is the DGR accelerator/cache adapter. I assume this permits the use of the accelerator along with another PDS card. (An Apple IIe card came installed in this LC).
Here is the back of the accelerator adapter. I hope this pinout will allow someone to reverse engineer the purpose of the three pin connector on the left side of this image.
The accelerator adapter connects to a header of the multislot PDS adapter board.
This is a very interesting product of its time. I will need to recap the LC motherboard and power supplies before testing it.
- David
The rear includes a second power supply switch and cord receptacle. There are four punchouts for PDS cards with external connectors. On the far right, there are four switches for enabling/disabling up to four PDS cards.
Below shows the interior with the PDS expansion board with all of the PDS cards removed).
The second power supply sits on a little shelf.
The power supply is a Golden Power Systems Ultratek Devices GP1037 with +5V@5A, +12V@1A, and [email protected] for 38 watts total.
Looking from the rear, towards to the front, notice that the floppy drive has been moved up to a shelf to align with the original LC top cover. Underneath the shelf is empty space, plus the usual location for a hard drive.
Atop the shelf above the original hard drive is space for a second hard drive. The SCSI cable has been swapped to accommodate two hard drives. A second power supply connector (for the second hard drive) is located on the DGR PDS adapter board.
The DGR PDS Adapter board features connectors for the PDS slot switches, power supply, second hard drive, and an accelerator/cache card adapter. Although there are four slots, the LC won't support their simultaneous use, with the exception of an accelerator cache card. Take note of the four IC chips at the top of the image. They each have a different color sticker, which likely indicates they are programmed differently. (Oddly, the blue dot IC is oriented in the opposite direction).
The ICs are 18CV8 electrically erasable logic chips.
The revision of this board (1994 A3) is newer than others I've seen posted.
Here is a shot of the resistor packs.
Presumably, the logic chips enable/disable the individual PDS cards. There is a header for the rear switches on the adapter board. J5 is has a pin cut off for keying purposes. The pin below it is not attached to anything on the cable.
Nothing fancy about the switch wiring. (The two loose wires broke of in shipping. They belong to the bottom switch.)
This computer came with a DayStar accelerator and a DayStar LC adapter. The green board in the middle is the DGR accelerator/cache adapter. I assume this permits the use of the accelerator along with another PDS card. (An Apple IIe card came installed in this LC).
Here is the back of the accelerator adapter. I hope this pinout will allow someone to reverse engineer the purpose of the three pin connector on the left side of this image.
The accelerator adapter connects to a header of the multislot PDS adapter board.
This is a very interesting product of its time. I will need to recap the LC motherboard and power supplies before testing it.
- David
