SD Systems - Other Boards
In the Summer of 1984 SD Systems expanded their name to "Syntech Data Systems"  and introduced a number of great looking new boards.  They ran these boards in two full page adds in The Microsystems Journal (August). I have never seen these boards and am not even sure if they were ever produced in any significant numbers.  If anybody has further information on these boards please let me know.

This was a dual processor board consisting of a Z80 (4MHZ) and an 8MHZ 8088. It had an onboard FDC which had 24-bit DMA capability and ran 5" & 8" drives. There was an 8K onboard monitor/ROM. There were 2 serial boards running up to 19.2 K Baud. There was also an onboard interrupt controller and a real time clock chip.

SD Systems were well known for their dynamic RAM boards. This was their only static RAM board -- and a good one at that.  It was completely IEEE-696 compatible handling 8 and 16 bit data paths.  It uniquely also had on board a backup battery and a real time clock/calendar chip.

2MB Dynamic RAM Board

This board could be configured as a regular RAM board or as a memory disk. It was completely IEEE-696 compatible handling 8 and 16 bit data paths.  It utilized 150ns RAM chips.

This was clearly an upgrade of the SD Systems SBC-100. The board sported a 4 or 6MHZ Z80, 64K of dual ported Dynamic RAM, 2-16K of EPROM's, Memory addressing to 16 MBytes. It also had a serial port, a parallel port and and a counter/timer.  It was completely IEEE-696 compatible. 

Versafloppy -III

This was a major upgrade of the Versafloppy-II.  It had all the things the Versa  floppy-II had but also you could control up to 3 Winchester hard disks.   data transfer could be either Port I/O or via DMA.  The hard disk had 20 bit single and 4 bit double burst detection span on 256 byte sectors. It was completely IEEE-696 compatible. 

Hard Disk Controller

This board could support up to 4 ST506 Hard disks. It also had two serial ports (up to 19.2 K Baud) and one parallel port. There was onboard memory for full sector buffering.  It was completely IEEE-696 compatible.