SCSI

Small Computer Systems Interface

Host Adapter Card
Copyright 1992-96 Western Horizon Technologies

HARDWARE INSTALLATION MANUAL

 INTRODUCTION
This manual contains procedures for installing the physical SCSI controller card into your
99/4a or Geneve computer system. It does NOT describe software functionality or usage of the disk
manager software. For information on use of the accompanying software, refer to the SOFTWARE
OPERATIONS MANUAL.

This product is based on the industry standard 53C80 SCSI controller chip manufactured by
several companies. It provides full SCSI level 1 support and allows integration of hard disks, floppy
disks and other SCSI devices into the 99/4a or Geneve system.

The SCSI interface is a standard described by ANSI. For more information about SCSI and it's
implementation in the 53C80 controller chip, please refer to the ANSI documentation or
manufacturers specifications. This document is intended ONLY to cover installation of the peripheral
card.

Western Horizon Technologies would like to thank you for purchasing this product. If you
have any difficulties with installatio n or operations covered in our warranty (see back page for
warranty information) please call:

Don O'Neil Bud Mills

Western Horizon Technologies Horizon Computer
3297 Woody Lane 166 Dartmouth Drive
San Jose, CA 95132 Toledo, OH 43614
(408)-934-0352 (419)-385-5946
 INSTALLATION
The SCSI interface card is a standard sized peripheral card for use with the Texas Instruments
99/4a, or Myarc Geneve computers. To utilize this card you will need the following system setup:

TI 99/4a Console,Monitor, 32K Memory, Peripheral Expansion Box

OR
Myarc Geneve, Monitor, Peripheral Expansion Box

Before installation begins, ensure that your computer is fully powered down and disconnected
from the ac outlets.

P ROGRAMS ON D ISTRIBUTION DISKS

Included with the SCSI card are utilities, and necessary programs to fully utilize the
peripheral. In most cases, a doc file is included on the disk, therefore no documentation is included in
this manual.

The distribution disks contain the following:

MDOS 2.5s (o r greater) The Geneve MDOS with SCSI support

SCUZZY A SCSI Hard drive sector editor
SDM A simple TI based SCSI Disk Manager (EA 3)
CAT A BASIC program to catalog a disk (SCSI or other)
README The latest information about the distribution

etc.....

You should read and familiarize yourself with all the documentation that is on the diskettes.
Most programs are intuitive and menu driven, those that are not have doc files on disk.

SETTING THE D IP S WITCHES

The SCSI card contains two sets of DIP switches for hardware setup, they are labeled SW1
and SW2 on the main board. SW1 Controls the CRU address of the card, and SW2 sets the SCSI ID
and TI/Geneve selection. These switches are set to a factory default of >1100 for the CRU and SCSI
ID 7 for TI operations.
 DIP SW1 C ONFIGURATION
SW1 Controls the CRU (Communications Register Unit) base address. The following table
indicates the possible settings for the SCSI peripheral, also included in this table are other peripherals
that may occupy the same address. It is important that the SCSI card occupy its own unique address
space for operation. If you have any of the listed cards, place the SCSI card and a known un-used

CRU BASE 1 2 3 4 5 6 7 8 Other possible hardware at this location

*>600 Off On On Off Off On On On *Addresses >600 through >F00 are only usable when
*>700 installed with an AT Keyboard and ROM upgrade
*>800 available separately. These addresses have no other
*>900 uses.
*>A00
*>B00
*>C00
*>D00
*>E00
*>F00
>1000 Mech. 80 Col Card, HFDC, HRD, 4a Memex
>1100 Any FDC, HFDC
>1200 Math Co-Processor
>1300 RS232 #1
>1400 AVPC 80 Column Card
>1500 RS232 #2
>1600
>1700 PGRAM, PGRAM +
>1800 Thermal Printer
>1900
>1A00
>1B00 Debugger Card, WHT VGA
>1C00
>1D00 IEE-488 Controller, MBP Real Time Clock
>1E00
>1F00 P-Code Card

address. The default address for the SCSI card is >1200. The recommended secondary location of the
SCSI card is >1000.
 FUNCTION POS NOTES
SCSI ID SELECT BIT 0 1 Normally ON = ID 7
BIT 1 2 Normally ON
BIT 2 3 Normally ON
System Select 4 ON= Geneve, OFF = TI

The SCSI card supports co-existence with other hard and floppy disk controller cards. For
example, you may already own a Myarc HFDC, it's default address is >1100, therefore you must
locate the SCSI card at >1000 or some other unused address.
A second, and most likely the most common configuration, is the use of the SCSI card with a
FDC, in this case, the FDC occupies >1100 and the SCSI card should occupy >1000 or any other
unused address.
Another configuration may be an HFDC and FDC (TI, CorComp, Myarc, etc..). In this case,
the FDC will occupy >1100, the HFDC >1000, and the SCSI card may be set to >1200 or any other
unused address.
There are too many configurations to list here, if you are unsure about how to set up the CRU
address for your system, please call for help.

DIP SW2 C ONFIGURATION

SW2 activates software related functions, the following table explains what these functions
are:

C ABLING
Included with the SCSI controller card is one internal/external drive cable. This cable has 4 50
Pin connectors on it, three at one end, and two at the other. To hook up SCSI drives, they must be
connected in a single continuous chain. This cable is provided so you can attach up to 3 internal/
external devices, or 2 devices and continue the chain off the third connector. If you intend to attach
more than 3 devices to the SCSI card, you will require additional cabling. For information about
available cabling, please call or write.

SCSI drives require termination for proper operations. Each drive may or may not contain
built in termination. Please refer to the drive's documentation on how to activate/deactivate
termination on the drive.
To attach a drive to the SCSI card, plug one end of the cable into the SCSI card (the end with
only one connector on it) and the other end (use the furthest connector for the furthest device) into the
disk drive. See the figure on the previous page.
Once the drive(s) are attached, you must activate/deactivate termination on them. Termination
should ONLY occur on the furthest drive on the cable loop. Activate the terminator on this drive, and
deactivate it on ALL others. Refer to your drive's documentation on how to activate termination.
Without proper termination, the SCSI system may not be stable. If you encounter problems with
reading or writ ing, check your termination. Too many terminators can inhibit data transmission, and
none can introduce excessive noise into the system.
It is recommended that you use the shortest distance from device to controller card. If you
have extra cable, you may wish to wrap it inside the drive enclosure for extra shielding.

RECOMMENDED D ISK D RIVES

Any standard SCSI hard drive that supports 512 bytes per sector is compatible with the WHT
SCSI host adapter. This includes all drives compatible with the IBM PC, Apple Macintosh and most
other drives. If you have any questions about the support of a particular drive, please call or write
before attempting installation. Installation of a non-supported drive may damage your card and void
your warrantee so please be careful in your drive selection. Often times users purchase surplus or
refurbished drives, these can often harm or damage ANY computer system. ALWAYS get a written
guarantee from the dealer that the drive has been tested and guaranteed that it will not do any damage
to your computer if installed correctly.
P OWER S UPPLIES
Any drive you purchase for use with the SCSI card will require a power supply for operations.
You may opt to install your SCSI drive in your P-Box. HOWEVER, due to power restrictions, BE
CAREFUL about installing ANY HARD DRIVE into a peripheral expansion box. Refer to the P-Box
documentation about available power in the drive bays and ENSURE that ANY hard drive or floppy
drive(s) you install do not exceed this power limit. IF YOU EXCEED THE SUPPLIED POWER
LIMITS YOU MAY DAMAGE YOUR P-BOX AND ALL CARDS IN IT. We will not be
responsible for ANY damage related to installing hard drives in the P-Box.

Some guidelines for installing drives in the p-box are:

* NEVER install a full height hard drive in the P-Box

* 3.5 inch hard drives are USUALLY low enough power to operate in the P-Box
* ALWAYS add up the power consumption of the drives you intend to
install in the P-Box and MAKE SURE it is less than the supplied power in the P-Box
* It is SAFEST to just NOT install drives in the P-Box.
* The drive supply lines in the Texas Instruments Peripheral Expansion Box are
rated at approximately 25 watts each.

You may choose to install your hard drive/floppy drives in an external case. Be sure that this
case is recommended for hard drive operations before installing the drives. Follow the above
instructions for cabling for any enclosure option.

ACCESSING SCSI DEVICES THROUGH A SSEMBLY

DSR link sub programs

The following is an abbreviated syntax of low level DSR link subprograms for access to SCSI
devices through GPL and assembly. Information on ho w to utilize these subprograms is provided in
the TI Editor/Assemble manual.

In general the >1X routines are for floppy access, >2X routines are for hard drive access. Error
codes are generally returned in CPU address >8350.

Sector READ/WRITE - Subprograms >10 and >20

>834A Returned sector number

>834C Unit # Where bit 0-3 is the drive number
bit 4 and 5 is the absolute sector size
0,0 = 256 bytes per sector
0,1 = 512 bytes per sector
1,0 = 1024 bytes per sector
1,1 = 2048 bytes per sector
bit 6 activates absolute sector size access
0 = use logical sector size of 256 bytes
 with absolute size of 512 bytes

1 = use absolute sector size in bits 4 &5

bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834D Read/Write Where 0 = write
1 = read
>834E Buffer start address in CPU or VDP RAM. 16 bit integer location. Buffer will match the
selected sector size of 256, 512, 1024 or 2048 bytes.
>8350 32 bit address of sector number to read/write

Format media - Subprogram >11 floppies

>834A Returned number of sectors per disk

>834C Unit # Where bit 0-3 is the drive number
bit 4 and 5 is the absolute sector size
0,0 = 256 bytes per sector
0,1 = 512 bytes per sector
1,0 = 1024 bytes per sector
1,1 = 2048 bytes per sector
bit 6 activates absolute sector size access
0 = use logical sector size of 256 bytes
with absolute size of 512 bytes
1 = use absolute sector size in bits 4 &5
bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834D # of tracks Must be 40 or 80
>834E Buffer start address in CPU or VDP RAM. 16 bit integer location. Buffer will always be 256
bytes.
>8350 Density Density of media where
0,1 = Single density FM, 125 K bits/second
2 = Double density MFM, 250 K bits/second
3 = High density MFM, 500 K bits/second
4 = Extra high density MFM, 1M bits/second
>8351 Number of sides Must be 1 or 2

Format media - Subprogram >21 hard drives, optical and tapes

>834A Returned SCSI status

>834B Returned SCSI message byte
>834C Unit # Where bit 0-2 is the SCSI address
bit 4-6 is the logical unit number

>834D Defect processing Where bit 0 activates defect processing

bit 1 allocate extra sectors/track for error mapping
bit 2 use existing sectors for error mapping
bit 7 use CPU defect table for error mapping
>834E Buffer start address in CPU RAM for error mapping. 16 bit integer location.
>8350 Returned 32 bit number of 256 byte logical sectors per disk
>8354 32 bit absolute sector size in multiples of 128 bytes.

Modify file protection - Subprograms >12 and >22

>834C Unit # Where bit 0-3 is the drive number

bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834D Protect code Where if 0, file unprotected. <>0 file protected
>834E Pointer to file name 16 bit pointer to 10 character buffer in CPU or VDP RAM

File/subdir rename - Subprograms >13 and >23

>834C Unit # Where bit 0-3 is the drive number

bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834E Pointer to new name 16 bit pointer to 10 character buffer in CPU or VDP RAM
>8350 Pointer to old name 16 bit pointer to 10 character buffer in CPU or VDP RAM

Access direct input file - Subprograms >14 and >24

>834C Unit # Where bit 0-3 is the drive number

bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834D Access code Where if 0, transfer file parameters, if not 0, indicates the
number of sectors to be read in a file. Starting
sector number in additional info.
>834E Pointer to file name 16 bit pointer to 10 character buffer in CPU or VDP RAM
>8350 Additional info Offset to information at >83XX
>83XX Buffer start address
>83XX+2 Number of first sector
>83XX+4 Status flags
>83XX+5 Number of records per sector
>83XX+6 EOF Offset
>83XX+7 Logical record size
>83XX+8 Number of level 3 records allocated
>83XX+10 MSB of first sector
>83XX+11 MSB of level 3 record
>83XX+12 Extended record length

Access direct output file - Subprograms >15 and >25

>834C Unit # Where bit 0-3 is the drive number

bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834D Access code Where if 0, create file and copy leve l 3 parameters , if not 0,
indicates the number of sectors to be written in a
 file. Starting sector number in additional info.
>834E Pointer to file name 16 bit pointer to 10 character buffer in CPU or VDP RAM
>8350 Additional info Offset to information at >83XX
>83XX Buffer start address
>83XX+2 Number of first sector
>83XX+4 Status flags
>83XX+5 Number of records per sector
>83XX+6 EOF Offset
>83XX+7 Logical record size
>83XX+8 Number of level 3 records allocated
>83XX+10 MSB of first sector
>83XX+11 MSB of level 3 record
>83XX+12 Extended record length

Buffer allocation - Subprogram >16

>834C Number of file buffers allocated

Set current pathname - Subprogram >27

>834C Unit # Where bit 0-3 is the drive number

bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834E Pointer to path name 16 bit pointer to 39 character buffer in CPU or VDP RAM

Create subdirectory - Subprogram >18 and >28

>834C Unit # Where bit 0-3 is the drive number

bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834E Pointer to directory name 16 bit pointer to 10 character buffer in CPU or VDP
RAM

Delete subdirectory - Subprogram >19 and >29

>834C Unit # Where bit 0-3 is the drive number

bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834E Pointer to directory name 16 bit pointer to 10 character buffer in CPU or VDP
RAM

Will not remove a subdirectory that is not empty

SCSI Direct - Subprogram >1B

>834A Returned SCSI status byte

>834B Returned SCSI message byte
>834C Unit # Where bit 0-2 is the SCSI ID
 bit 3 polled I/O select
1 = use P-DMA access
0 = Force polled i/o
bit 6 data buffer location
0 = VDP RAM
1 = CPU RAM
bit 7 CDB buffer location
0 = VDP RAM
1 = CPU RAM
>834D Read/Write Where 0 = write
1 = read
>834E CDB buffer 16 bit start address
>8350 CDB buffer 16 bit length
>8352 Data buffer 16 bit start address
>8354 Data buffer 16 bit length

Examine SCSI unit - Subprogram >1C

>834A Returned SCSI status byte

>834B Returned SCSI message byte
>834C Unit # Where bit 0-2 is the SCSI ID
bit 7 buffer location
0 = VDP RAM
1 = CPU RAM
>834E Buffer 16 bit start address for 44 byte packet
Packet structure:
Offset Description
0 8 bytes of information identical to the response to the SCSI inquiry command
8 8 bytes of vendor ID string
16 16 bytes of product ID string
32 4 bytes of product revision string
36 32 bit total number of sectors on device
40 32 bit device sector size

P ARTS LIST
This list is to be used only for the purchase of replacement parts for repair and/or backup.

U1-U3 74LS244
U4 74LS245
U5 74LS125
U6 74LS/ALS520
U7 16V8 GAL, WHT Part #: CRU v1.0
U8 74LS138
U9 74LS251
U10-U11 74LS259
U12 20V8 GAL, WHT Part #: ADDRESS v2.0
U13 16V8 GAL, WHT Part #: DMA v4.0
U14 62256 SRAM (or equivalent 32K by 8 SRAM) 250ns or Better
U15 27C512 EPROM, WHT Part#: SCSI DSR v1.0
U16 53C80 SCSI Controller chip

C1 10 uF, 16V
C2 1uF, 16V
C3 10 uF, 16V
C4 Rev E: .1 uF, Rev F: 10 uF, 16V
C5 Rev E: .1 uF, Rev F: 1 uF, 16V
C6-C22 .1 uF, Titalium

R1 47 ohm, 1/4 Watt

R6 Rev E: 1K ohm, 1/4 Watt, Rev F: 2K ohm, 1/4 Watt
R7 Rev E: not present, Rev F: 1K ohm, 1/4 Watt
R2-R5 2K ohm, 1/4 Watt

N1 2N3904 Transistor
D1 1N914 Diode (installed on reverse side on Rev E)
L1 RED LED

TERM 1-3 220/330 ohm terminators (on Rev F only)

SW1 8 Position DIP switch

SW2 4 Position DIP switch
M1,M2 MC7085, 1 Amp, +5V regulator (M2 present only on revision F)
C1,C2 50 Pin dual row header, keyed (C2 present only on revision F)

This product was brought to you through the combined efforts of many individuals:

Don O'Neil Hardware Design, Board Layout, Documentation

David Nieters Software development team member, TI DSR, Disk Manager
Brad Snyder Software deve lopment team member, sector editor design
Mike Maksimik Software development team member, MDOS
Tim Tesch Software development team member, MDOS
Dave Connery Special Consideration
Bud Mills Assembly, Sales, Funding

THREE-MONTH LIMITED WARRANTY

Western Horizon Technologies Inc. extends this consumer warranty only to the original consumer
purchaser.

WARRANTY COVERAGE

This warranty covers the electronic and case components of the diskettes and board. These
components include all semiconductor chips and devices, diskettes, plastics, boards, wiring, and all
other hardware contained in the board( "the Hardware"). This limited warranty does not extend to the
programs contained on the diskette or cartridge or the accompanying book materials ("the Programs").