2.11 Detailed Connections For Specific Computers; Computers With Specific Serial Interfaces; Commodore 64, 64C, 128, Vic 20; Ibm Pcjr - Advanced Electronic Applications PK-88 Operating Manual

PK-88 OPERATING MANUAL

2.11 Detailed Connections for Specific Computers

Many computers require a serial port adapter card that incorporates the necessary interface
circuitry. Some popular computers in this category are the Apple II series, the IBM PC (and
many compatibles), the Tandy 1000, 1200 and 3000-series computers and the Sanyo MBC-
55X series. If you are using one of these computers refer to the section, 'Other Computers
with Nonstandard Serial Ports.'
Computers that do not have a serial port and do not permit use of a suitable adapter or lev-
el converter cannot be used with the PK-88.
2.11.1

Computers with Specific Serial Interfaces

Apple Macintosh
The Macintosh serial port is compatible with the RS-422 standard, but can be used with
the RS-232C port on the PK-88.
Wire a cable as shown below:
Note that pin 1 is not connected inside the Macintosh. Use a shielded serial cable and
connect both pins numbered '1' to the shield. Connect pin 1 at the Macintosh end to the
main ground on the computer.
2.11.2

Commodore 64, 64C, 128, VIC 20

Commodore and other manufacturers sell a signal level converter that is installed in the
User Port Connector on the rear of the computer. The converter changes the computer's
internal TTL voltage levels to the proper RS-232-C voltage levels and polarities. Unless
you are very familiar with the inner workings of your computer, you should purchase a
level converter rather than trying to 'do it yourself.'
2.11.3

IBM PCjr

The PCjr uses standard RS-232-C voltage levels; however, the connector is not standard
and is sometimes hard to find. Pin-out information can be found in the IBM PCjr Technical
Reference Manual.
Some computer dealers sell an 'IBM PCjr Adapter Cable for Serial Devices' that converts
the connector on the PCjr to standard RS-232C. The cable is attached directly between
the PCjr and the PK-88. The cable is only about three inches long; you may want to get a
male-to-female RS-232C extension cable.
MACINTOSH (DB9P)
1.................................................1
5.................................................2
9.................................................3
3.................................................7
7..................................................8
6.................................................20
PK-88 (DB25P)
2 - 16
INSTALLATION
PK-88 - 32