Re: HD20

[mjmahon@aol.com (Michael J. Mahon)]

Bart reported:

>I am sitting in my shop with an open HD20 in fromt of me.  Inside we find a 
>Power Supply a fan, a disk, and a board.  The disk is a Rodime Model 552. 
>Connector seems to be a 26 pin affair similar to a Apple II SCSI card
>connector 
>A DB25 (DE? ;)  SCSI  ribbon will fit here.which leads to a matching
>connector 
>on the baord.  again a 26 pin connector.  the rest of the board is...:
>Silk Screened Apple Computer c 1985 with no Rev number
>socketed chips:  1st seems to be a Apple one  marked 620 VM 
>B414...2365-1239....342-0343-B... c 85 Apple   Korea  it is a 28 pin one and
>it 
>is twined by another 28 pin that is marked: 625v  
>c244....VP4060-0001....344-0041-B...c Apple 1982 1983, a longer 40 pin one
>(not 
>socketed)  marked SR0103...341-0339-a...APple 85- 8622  the next chip is a 
>HM6116-3 and at the bottom (front of case) a socketed large square chip
>marked 
>LIaII85...3440600-1
>Apple 85.... TAE 8624 
>Also there is a 7.5MHz occilator and a LS132 and a LS109.
>Assortied capacitors, resistors, the conector for the male and female 19 pin 
>floppy ports, a light bulb (not an LED, a bulb), and a power transistor seem
>to 
>be the whole of the board.  Now, can anyone make sense of that?

Sounds like a tidy little single-board-computer to translate Smartport
protocol into SCSI.  I wonder what processor it uses?  Could
it be a 6502?!  At least one of the 28-pin chips is a ROM.

A 26-pin connector is non-standard for SCSI, though.  Most older SCSI
drives have a 50-pin (dual row) connector.

-michael

 Email:  mjmahon@aol.com
 Home page:  http://members.aol.com/MJMahon/