MOD CHIP QUESTIONS
1.What is a "mod chip"?
2.How does a mod chip work?
3.What kinds of mod chip are there?
4.What is the differences between the number of wires?
5.What is the history behind the mod chip?
6.Why won't my early mod chip work on a SCPH-550x or later console?
7.What is an "anti-piracy mod chip"?
8.How does a anti-piracy mod chip work?
9.What is a "color correction chip"?
10.How does a color correction chip work?
11.Does the mod chip cause FMV skipping?
12.Why don't mod chips work on current Japanese PS models?
13.Where can I buy these chips?
14.How do I make CD-R copies of games?
Q1. What is a "mod chip"?
A1. The "mod chip" is a programmable microcontroller that when
connected to a Sony Playstation will allow you to play games from any region,
copied CD-R games and bootlegged games, generally from southeast Asian sources,
to work as well. (a.k.a HK copies)
Q2. How does a mod chip work?
A2. The mod chip will generally have a minimum of two i/o connections to
the playstation mainboard. These go to opposite sides of an inverter
gate which transmits subcode data information from the CD controller to the main
CPU. This data stream indicates the region of the CD in use.
By driving the input of this gate logically low, the output is floated. Then on
the other side a new data stream can be injected by the mod chip.
The data that the CPU is looking for is a serial data stream at 250bpsconsisting
of the characters SCEI, SCEE or SCEA depending on whether
the console is Asian, PAL or North American. By sending all three data streamsin
a rotating sequence, the chip can satisfy the console that it is
reading a CD of the appropriate region.
Q3. What kinds of mod chip are there?
A3. The original mod chip was implemented on the PIC16C54, a popular
inexpensive OTP EPROM-based 8-bit microcontroller from Arizona
Microchip, later known as just Microchip. Early reverse-engineered versions of
the chip were implemented on the same hardware. The initial
"Old Crow" reverse of the chip used a Zilog Z8-series microcontroller,
which is comparable feature wise with the 16C54. A back-port soon
followed to the 16C54, as well as the EEPROM based16C84, which is very popular
outside the US, particularly in the pirate satellite TV industry
in Europe. In early 1997, the 12C508 microcontroller became available from
Microchip. The "Old Crow" as well as at least one of the earlier
reverse-engineer sported the mod chip code to this chip independently. The
12C508 (and its double-size memory but otherwise identical sibling
the 12C509) represented a cheaper (approximately half the cost for blanks) and
simpler (did not need a reset circuit, saving one connection, and
could be run off an internal RC oscillator, optionally saving a second) platform
for the modchip code. In addition, several other individuals have
ported the Old Crow code to run on other processors, most notably the Atmel and
Q4. What is the differences between the number of wires?
A4. Historically there have been mod chips with 4, 5, 6 and 10 wires. The
original mod chips were 10-wire. There have been claims that four of
these wires are red herrings, but having seen source code for the original Hong
Kong 10-wire chips, these wires did actually serve a function to
time the start-up of the data sequence. All known 10-wire chips are
16C54s.Connections: Ground, Vdd, Clock, Reset, Gate, Data, 4 timing
inputs.6-wire chips are generally 16C54 or 16C84 based. Instead of timing when
to start sending the data stream they simply just start sending it
after an initial delay from power-on or closing of the drive door. Connections:
Ground, Vdd, Clock, Reset, Gate, Data. There are several variants
on 5-wire chips. Known to exist are Atmel AVR-series, Zilog Z8 and Microchip
12C508. All are chips that do not require the special reset
requirements of the earlier Microchip parts. Connections : Ground, Vdd, Clock,
Gate, Data. The 4-wire chip took advantage of the Microchip
12C508/9's ability to run from a (reasonably accurate) internal RC clock. This
is the most common chip found today. This is the minimum number
of connections for a mod chip using the method of defeating the region detection
used in A2. Connections: Ground, Vdd, Gate, Data. The "Old
Crow" did create a prototype 3-wire chip which was more a
"proof-of-concept" than anything else. It worked by omitting the gate
carefully monitoring the incoming bit stream on the data connection, then
forcing individual bits in the bit stream high at appropriate times. The
timing required was rather complex and due to the nature of the bit stream, only
would function on a North American console. Connections:
Ground, Vdd, Data.
Q5. What is the history behind the mod chip?
A5. The original mod chip was created in Hong Kong in early 1996 by a
western engineer working under contract to a Hong Kong company.
These chips were sold world wide for anywhere from US$40-80.During 1996 there
was at least one successful reverse-engineering of the chip,
done by an individual in the Netherlands. There may have possibly been others.
The effect of these chips was to drive the pricing down to the
US$25 level as the original Hong Kong sources had to compete with their western
competition. The real breakthrough occurred in early 1997
when the "Old Crow", using an original Hong Kong-sourced chip provided
by the author, successfully reversed the chip and made the source
code publicly available on a web site. Within weeks the price of chips was down
to the US$10-20 level. Later in 1997 the availability of the
lower cost 12C508 microcontroller and a port to it by the Old Crow and the
unnamed Dutch programmer (done independently within a week or
two of one another) has driven prices to the current $10-15 range ($6 here)
Q6. Why won't my early mod chip work on a SCPH-550x or later console?
A6. The early (pre-june-1997 non-4-wire) mod chips had timing loops
dependent on the clock frequency provided from the PS console being 4.0
MHz. The SCPH-550x and later consoles had a different clock frequency on the
mainboard, rendering older chips useless in these consoles.
Later releases of the "Old Crow" code (v5.3 and higher) for
microcontrollers using externally supplied clock frequencies had support for
boards by alternately sending the data streams at rates compatible with one
clock, then the other
Q7. What is an "anti-piracy mod chip"?
A7. Playstations equipped with anti-piracy mod chips will boot original
games from all regions but will refuse to boot CDR copies or bootlegs.
They are popular with game stores that wish to sell imported games without
losing business to piracy.
Q8. How does a anti-piracy mod chip work?
A8. Anti-piracy chips are somewhat more sophisticated than the standard
mod chip code. Instead of blocking the original data stream entirely,
the anti-piracy chip lets the first three bytes of the four byte sequence pass
through the inverter gate, then blocks the final byte while sending
its own altered done-byte code. The 3-wire proof-of-concept chip mentioned in A4
is a variant on this idea.
Q9. What is a "color correction chip"?
A9. When playing an NTSC game on a PAL console or vice-versa, you will
generally get a picture without color. Unless you are using a TV
with a SCART connector and an appropriate cable from the PS, are able to process
the signal through a multi-system VCR or have a multi-system
TV, the only way to view these games in color is with a color correction
Q10. How does a color correction chip work?
A10. Video in all PS models is provided by the Sony CXA1645 video
generator chip. This chip is capable of generating both PAL and NTSC
video, however the color burst signal overlaid on the video is generated by a
fixed-frequency crystal oscillator on the main board. The color
correction mod works by hard-wiring an alternate frequency color burst crystal
to the CXA1645 chip. Note that the color correction
modification involves either cutting copper traces on the PS main board or
unsoldering pins from surface mounted components. It has the
potential of permanently breaking the console if botched and should only be
performed by competent installers. If you have he capability of
getting corrected color by SCART cable or multi-system TV, you would be better
served by using one of those rather than installing a color
mod. The color correction modification is generally sold in one of two forms,
either as a separate sub-circuit from the mod chip (in which case
the raw cost for the parts can be as low as US$0.60, half the cost of the
average blank 12C508 chip) or more increasingly on a well-engineered,
professionally replicated printed circuit board fitted along with a mod chip
under the common name 'color mod / color mod'. These boards offer
an all-in-one solution as well as some element of additional safety during
install and secure mounting away from any metal components that
might short the chip out.
Q11. Does the mod chip cause FMV skipping?
A11. In a word, NO. The mod chip only affects information coming from the
CD subcode channel. This is out of band data. It does not touch
the regular data being read off of a CD. The well known PS FMV skipping is
caused by bad engineering in the CD assembly itself. Or burning at too high a
Q12. Why don't mod chips work on current Japanese PS models?
A12. Since partway through the production run of the SCPH-3000 model
consoles there has been a firmware incompatibility that renders them
incapable of running other region games. Copies of Japanese games will boot, and
strangely enough copies of other region games with the boot
sector of a Japanese game substituted will boot, isolating this problem to
something related to the boot sector.
Q13. Where can I buy these chips?
A13. The best place for purchasing them is here.
a. Installation instructions - detailed, online, printed copy by request
b. Shipping method/packing - COD available in US, Priority is available for
actual shipping fee, FREE regular mail, ESD packaged.
c. Reputation/professionalism - We have been around since 17 Oct. 97. Does our
website look well-run? Please leave feedback.
d. Availability of credit card/online ordering - We take credit cards. It is a
secure web server.
e. Technical knowledge - Our technicians are certified and also hard core gaming
f. Other Value-added - Pre-wired chips are available. Installation service is
g. Netiquette - We never spam the newsgroups or individuals.
Q14. How do I make CD-R copies of games?
A14. Click backup for that information.