The Lil Old Sinclair Computer Technical Information Repository

miscellaneous information

information that doesn't belong anywhere else, so its here ;)

Datasheets

SED9420 datasheet - PDF format (263k) courtesy of Ian Worsley
  CMOS Data Separator for FDD

Disciple / +D

Compatibility issues with newer floppy disk drives

Pin 10 which selects Drive 0 seems to not be connected with new floppy drives which can cause problems

plusdfloppy.png - PNG format (5.83k) . see notes below

Note that it is best to use a standard floppy cable plugged straight into the drive first making sure that there are no twists between the interface and drive.

If your drive has a jumper then set it to DS 1 if it starts from 0 and DS2 if it starts from 1 that should allow the drive to work normally as drive 1, drive 2 can be selected by putting the jumper in the next select up.

If your drive does not have a jumper, try the normal method first and if this does not work you will have to do some DIY on your floppy cable as shown in the diagram.

Thanks to Ian for this one

Interface One

• Interface One Issue 4 Topside Showing Component Layout - jpg format (225k)
• Interface 1 Circuit Diagram [Issue 4] - PNG format (78.3k) courtesy of Andras Petri

the following were supplied by Andras Petri

• Interface 1 Circuit Diagram [Issue 4] - PNG format (78.3k)
• Interface 1 Microdrive Circuit Diagram [Issue 4] - PNG format (30k)
• Multiface 1 Circuit Diagram - PNG format (71k)

All three above as in ZIP file - 178k