Memory Card: Revision B

Last Updated: November 09, 2005 09:48:34 PM

Not Yet Produced

Revision B not yet produced of the memory card with the RAM installed at 0x0000 – 0x7FFF and the EPROM at 0x8000 – 0xFFFF. ( FIX test with new PCB and picture) The jumper blocks on the left enable and disable 4K memory blocks. This card has RAM 0x0000 – 0x6FFF and EPROM 0x8000 – 0xEFFF areas are enabled.


The memory card contains 64K of RAM and 64K of EPROM made up four 32K x 8 chips (2 RAM, 2 EPROM). The RAM and EPROM are each spread across the entire 64K address space of the 1802. (FIX ADD JUMPER DESCRIPTION). The card was designed with this flexibility to accommodate old software of my own and new software such as ELF/OS. The card replaces the original System-4 16K Ram card.

Issues/todo log

Date Description Status

Schematics, board layout, and operational description

Revision Production Date Schematic Layout Operational Description
A Dec-16-04 mem3.sch mem3.brd Rev. A ops notes
B Current Development Board


mem3-b.sch mem3-b.brd Rev. B ops notes