Tandy 1000 Technical Reference Manual

Tandy 1000
1000 and IBM I/O Bus Cross Reference Chart
Technical Reference Manual
Pin No.
B18
B17
B16
B15
B05
B21
B22
B08
10
Signal Name
DRQ1 *
DACK1 *
DR03*
DACK3*
-5VDC
RFSHRQ*
BREQ*
AUDIOIN
Description
IBM - This signal is always available on the
IBM
PC.
TANDY 1000 - DMA request 1 is available
only
on the I/O bus when the Memory/DMA
board
is installed.
IBM - This signal
is always available on the
IBM
PC.
TAN DY 1000 - DMA grant 1 is only
available
on the I/O bus when the
Memory/DMA board
is installed.
IBM - This signal
is always available on the
IBM
PC.
TAN DY 1000 - DMA req uest 3 i only
available
on the I/O bus when the
Memory/DMA board
is installed.
IBM - This signal
is always available on the
IBM
PC.
TAN DY 1000 - DMA grant 3 is only
available
on the I/O bus when the
MemorylDMA board
is installed.
IBM - - 5VDC
is always available.
TAN DY 1000 - - 5VDC is not installed on
the I/O bus, but a modification
is available
through
an authorized repair center.
IBM - This signal functions
as a refresh re-
quest on the I/O bus, but is labeled Interrupt
Request
7.
TANDY 1000 - Same function as on the IBM
PC, but different pin designation.
IBM - This signal functions
as a bus request
on the I/O bus, but is labeled Interrupt Re-
quest 6.
TANDY 1000 - Same function as on the IBM
PC, but different pin designation.
IBM - Reserved
TANDY 1000 - Audio input
is supplied from
an optional board on the I/O bus to a
multiplexer
on the main logic board for an
output to the external speaker.

Tandy 1000 Specifications

General

Processor	Intel 8088
Processor Speed	4.77 MHz
RAM	128 KB (expandable to 640 KB)
Operating System	MS-DOS 2.11
Manufacturer	Tandy Corporation
Release Year	1984
Storage	Single or double 5.25" floppy disk drive (360 KB), optional hard drive
Sound	Tandy 3-voice sound
Ports	Parallel, Serial
Graphics	CGA (Color Graphics Adapter)
Graphics Modes	320x200, 640x200