Calibre UK IC Communication Adapter ICA93LV - Manual (Page 3)

Revision 1.7 Page 2 of 27
09/12/1999
2. Configuring the Adapter
NOTE: MANY COMPONENTS ON THE ADAPTER CARD ARE STATIC SENSITIVE.
OBSERVE NORMAL STATIC SENSITIVE PRECAUTIONS WHEN HANDLING THE
CARD!
The adapter is supplied in a standard configuration which should suit most applications.
However, some features are link selectable. Read the following section to change the
configuration.
The standard configuration is:
base address = 0310 (Hex)
number of wait States = 1
hardware interrupts disabled
bus termination & protection off
2.1. Setting the Adapter Base Address
The card occupies a pair of PC I/O addresses and responds to input/output commands. Set the hex
starting address of this pair using LK1, LK2 and LK3 within the following range:
LK3 LK2 LK1 Start Address(Hex)
0 0 0 0310
0 0 1 0312
0 1 0 0314
0 1 1 0316
1 0 0 0318
1 0 1 031A
1 1 0 031C
1 1 1 031E
The standard configuration is LK1-3 at “0” giving a start address of 0310 (Hex).
2.2. Wait State Generator
Data validity is assured by delaying the PC bus using the IOCHRDY signal. The number of wait states
imposed on the PC bus is link selectable from 1 to 4 using LK4.
The card is supplied with LK4 in the “1” position, which is suitable for machines up to 10 MHz clock rate. If
your machine implements dynamic speed switching on I/O channel access (as do most good
PCs), position 1 is correct no matter what its clock speed.
If a PC with a faster clock is used which does not switch speed on I/O channel access, it may be
necessary to increase the number of cycles delay to achieve the same absolute time delay.
Use the following table as a guideline for choosing the right position for your machine:
PC up to 10MHz Position 1
PC over 10MHz, up to 16MHz Position 2
PC over 16MHz, up to 20MHz Position 3
PC over 20 MHz Position 4
The best position is the minimum number of wait states while maintaining data security. This can easily
be found by trial and error.
The ICA93 operates correctly in all 'well behaved' faster machines. In most cases just one wait state will
be fine in even the fastest of machines. However, some rogue PCs that do not obey correct I/O timing
may cause problems occasionally. If you suspect this is a problem, try using the adapter in another
computer if possible to prove the fault. For further help regarding timings contact your ICA93 supplier for
technical support. The standard configuration is with one Wait State selected.