The Power Supply - RCA CDP18S711 Instruction Manual

6
CHIP-8 includes a real time clock, random number
generator, decimal conversion, and digit or graphic
display capability. It only uses 512 bytes of RAM leaving
over 1024 bytes for programs in a 2048-byte system.
(You can get an additional 2048 bytes of RAM by
plugging four more RAM chips into your card.)
With the aid of the User Manual for the CDPI802
COSMAC Microprocessor, MPM-201, you can explore
the fascinating world of machine language programming.
You can even combine, machine language programs with
CHIP-8 programs or develop your own interpretive
languages.
For hardware hackers, COSMAC VIP provides
complete external interface
suggestions for inexpensive external devices and
applications are listed in Section VI. Logic diagrams,
data sheets, trouble -shooting hints, and test programs are
provided so that you can explore the hardware in as much
detail as you want.
This manual assumes that you are familiar with
computer basics from reading one or more of the
excellent magazines devoted to home computing. You
should understand RAM, ROM, memory addressing,
instructions, bytes, etc. The use of a scope
capabilities. Some
Photograph of COSMAC VIP (Video Interface Processor) CDP18S711 The
cables in the upper right are for the video display and for cassette
operation. Cable on the upper left goes to the power converter.
RCA COSMAC VIP Instruction Manual
will facilitate setting up the cassette system and iden-
tifying hardware problems in the rare case where they
occur. Hex notation is used in this manual unless noted
otherwise. (One byte equals two hex digits.)

The Power Supply

The output wires of the internally regulated power
converter supplied with the COSMAC VIP CDP18S711
are connected to the +V DC and GND pads at the back
left comer of the PC card. The power converter output is
regulated +5 V DC at 600 mA. If you wish to add more
RAM to your system, however, you may need a
higher-current power supply. A 2048-byte system
requires about 350 mA (600 mA worst case). A
4096-byte system should require average current of
about 600 mA. If, however, your RAM chips require
above average power, you may need to supply as much
as 900 mA at 5 V DC, regulated. You can also use your
own unregulated 8 to 10 V DC power supply by adding
voltage regulator U28 (plus heatsink) to your COSMAC
VIP card and cutting the printed circuit link called LKI.
Never apply more than +5 V DC to the card unless the
U28 regulator has been added and link LKI cut.