![S100 Computers](../../../Header/S100_Banner.jpg)
Vector Graphic 64K Dynamic RAM
This was Vector Graphics workhorse RAM
board for all their later systems.
![VG 64K DRAM](VG 64K DRAM.jpg)
The Vector Graphic
64K Dynamic Memory Board provided up to 65,536 (64K) 8-bit bytes of random
access memory. It could be used in most S-100 bus computer using a Z-80 CPU
board. (Minor modifications may be necessary if system was not shipped with this
board). It was an extension of their
48K RAM card.
The board had output buffer disable
compatible with the Vector Graphic ZCB Board, which activates the phantom
in response to POC and Reset. However DMA cycles not interrupt CPU for
longer than 2X10-3 seconds without generating the necessary refresh
signals. The board had jumpers to disable either one or both of the two top RAM
portions (C0O0H to DFFFH and EOOOH to FFFFH). There was a switch selectable
bank number assigned to each 64K board in a system. The system selects a board
by outputting a byte via port 40H to the appropriate bank. For simple 64K
systems the bank is bank 0. In that state, it is automatically selected when
computer is first turned on or the RESET button is depressed. If the board
does not work first check it is setup for bank 0.
The schematic for this board can be seen
here.
The manual for the board can be obtained
here.
Other Vector Graphic S-100 Boards
Dual FD-HD Controller
FlashWriter-II
Bitstreamer-II
48K-RAM
64K-RAM
8080-Board
8K-RAM
EPROM
FDC Micropolis-FDC
Z80-Board
SBC
This page was last modified
on
01/08/2011