MEMORY PLUS Manual By Lee Davison
Page 11
EPROM Programming
The usefulness of the EPROMs on the MEMORY PLUS board is enhanced by the
inclusion of on board EPROM programming facilities. The INTEL 2716 EPROM
is electrically programmable and ultraviolet light erasable. The user can
buy or build an ultraviolet light eraser. MEMORY PLUS provides the parts
required for the programming of the EPROMs. These parts consist of the
following items:
EPROM Programming Socket: Socket 79 is a 24 pin socket located toward
the lower right hand corner of the board. The EPROM to be
programmed is placed in this socket.
+25 Volt Regulator: +25 volts is required for programming the 2716.
This may be provided directly by the user at pin A-22 of the
MEMORY PLUS application connector. Since this voltage is so
critical, and since an over voltage can destroy an EPROM, an
on board regulator circuit is provided. This will provide about
24.7 volts when supplied with +27 to +30 volts at pin E-3 of the
MEMORY PLUS expansion connector.
Control Lines: The EPROM requires eleven (11) address lines, eight (8)
data lines, and two (2) control lines. All but three of these
lines are provided by the MEMORY PLUS VIA 6522. The remaining
three lines come from the MICRO port B: PBO, PB1, and PB2.
Timing: EPROM programming requires a 50 millisecond pulse be applied
to the EPROM. The VIA 6522 includes a timer which is used for
timing this interval.
EPROM Programming Program: The control of the programming is handled
by a program run on the MICRO. This program is provided in the
form of a source listing in this manual and as a cassette tape
included in the MEMORY PLUS package.
The 2716 EPROM may be programmed one location (byte) at a time, or the entire
EPROM may be programmed. The steps required to program the EPROM are:
1. With the power off, insert the EPROM to be programmed into the
Programming Socket.
2. Turn on the power and load the data to be copied into the EPROM
into any portion of memory. This may be RAM memory loaded from
cassette (or by hand) or may be another EPROM which is going to
be copied.
3. Load the EPROM Programming Program from cassette (or by hand)
into memory (locations 0000 to 00D8)
4. Make sure the following application connector connections are
in place:
MICRO A-9 TO MP A-19;
MICRO A-10 TO MP A-20;
MICRO A-l1 TO MP A-21
Page 11
Last page update: 8th December, 2002. |
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