Ithaca Audio
Z80 CPU Card.
This was Ithaca Audio's (later known a Intersystems) first
S-100 card.
The card was designed
to be a drop in replacement for a 8080 CPU card in Altair and IMSAI computes. The
card was sold as a kit. It did have an onboard ROM allowing a monitor boot
directly from the board. It was a very clean design. Was very reliable and
sold well.
The card had the following
features:-
On board 2708 EPROM addressable to
any 4K boundary above 32K
Power-on-jump to any 4K boundary
above 32K, or the on-board 2708
A wait state may be added to any:
- Ml cycle
- Memory Request cycle
On-board ROM cycle (for use at 4 MHz)
Input cycle
Output cycle--
On-board run-stop flip-flop and optional
generation of MEMORY WRITE allow front panel-less operation-
Selectable 10 addressing
mode:
- 8080 mode where peripheral address byte is duplicated
on high and low order address bytes
- Z-80 mode where the peripheral byte appears on
the low order address, and the contents of the accumulator appears on the
high order byte, allowing simultaneous I/O
DMA Grant tri-states all signals from
the processor board
8224 clock generator provides
8080 look-alike Clock
l
and Clock2
for the S-100 bus
The manual for this card can be downloaded
here.
Other InterSystems S-100 Boards
64K Dynamic RAM
8K RAM
EPROM
IA-Display
FDC
IO-Card
Z80-Series-II
Z80
FPB
256K Dynamic RAM
16-64K EPROM
HDA
Z80-Series_III
6-SIO
EPROM Emulator
RTC Board
This page was last modified
on 01/08/2011