68kMLA Classic Interface

This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.

Click here to select a new forum.

Lisa I/O board parts

Posted by: Canby Fat Mac on 2017-03-25 20:46:22 I'm rebuild a Lisa 2/5 and I able to find a MC1489PD, but I'm not able to find a MC1488PD only a MC1488P (no D) is the MC1488P a suitable substitute? Also does anyone know what the thing is below R46? The battery's ate them.

Posted by: Themk on 2017-03-25 20:53:45 The thing right under the silkscreened R46 is a resistor pack. It is indicated RP4 underneath it in the silkscreen. Here is the info on RP4 Basically, it is just a bunch of 10K ohm resistors. Also, the Lisa schematics are available at http://lisaem.sunder.net/books.html

Posted by: NJRoadfan on 2017-03-25 22:12:23 The MC1488/1489 pair are the line receiver/driver for the serial ports. Going by this part of the schematic. http://lisaem.sunder.net/LisaSchem/Lisa210SysIO3.gif and the datasheets for the parts http://www.onsemi.com/pub/Collateral/MC1488-D.PDF http://www.onsemi.com/pub/Collateral/MC1489-D.PDF You should be good, just make sure its a DIP package chip.

Posted by: Themk on 2017-03-26 12:16:59 I did some searching around, and this is the specific resistor pack you need to order for your Lisa I/O board: http://www.mouser.com/ProductDetail/Bourns/4308R-101-103LF/

1