Amstrad Cartridge Identification Device
The ACID (Amstrad Cartridge Identification Device) protection chip is used in the cartridges of the Plus series and the GX4000 game console.
It is labelled with "Amstrad 40908".
Because this chip was a custom creation by Amstrad it is currently not possible to replace this chip nor to build new cartridges, because it is not known how it works.
The End of the Darkness : A New Hope
At first was the age of grim darkness, ignorance en despair.
For twenty years, the once glorious Amstradom struggled and was about to loose it to the might of the Commodore's legions and Nintendorks hordes, a fight It wouldn't win.
Remembering with Nostalgia old ages of glory, gay old time when the Amstradom was young and fool, as told by the Elders. Until one day the end of a Nightmarish Time was about to End as announced by an obscure and lost prophecy.
A Lone Man came to stand before the Foul Darkness of Ignorance.
"Give me two days, and I'll bring you the light, I'll bring you hopes." he said to the crowd of the Amstradom The Amstrad Peoples frowned in horror and fear.
"Heresy, you know that None can stand before the ultime Might and Eldricht Arcane of the Mighty ACID, bringer of extinction, destroyer of the Worlds." scanded the crowth in anger and fury.
"You fool, we are Doomed into Oblivion, the Commodore's Legions and Nintendo Hordes shall rule us all..." cried others.
"Burn this Foul Heretic for giving us false hopes ! we must accept our fate !" a last man hystericaly screamed.
Then Fano the Wise accomplished his destiny.
"I believe in you, Lone man, accept my humble sacrifice" he said gently, a tear in the eye.
For era we will remember Him who who sacrified his beloved Cartridge for the cause. Strenghtened by the Blood of the martyr, the Lone Man Hurled himself into the fray.
Four days and Four nights, he fought.
The Battle was Epic, sounds of the bits tearing the sky, Heaven and Hell colour clashed in a furious destruction of blind madness.
Four days and Four nights, he Braved.
So Grand was the cause and so inspiring was His Fight.
At first sceptic, the Amstradom were slowly gained to the Holy Cause of the Lone Man.
Fortified by the exemple of He who fought desperately yet with no hesitation, conscious that Grand Scheme was being at work.
Four days and four night.
Then the Colour Clash ended.
The chanting cheerfull acclaims of Amstradom stand before the Lone Man.
Accompanied by colourfull sprites, smooth scrolling rolling as DMA channels rejoyced loudly, in a rainbow of four-thouzand-and-ninety-six Colours of of Space..
Victorious and Untainted.
He who defeated the Vile Beast.
"Four Days" he said.
"Fours days and four nights, the Task was even greater than I could believe. How Fool was I... but I did overcame."
And future generations in Amstradom would remember Him as the Saviour, the Messiah, the Bringer of Light against Darkness.
He who shown us the way.
And NoCa$h was his name, the man who degfeated the ACID chip.
Twenty years and Four days.
A new Era was to begin. '
The beast unleashed
ACID chip is soon to be beterly understand, and many stuff are to come.
Pinout
+--()--+
GND | 1 16| +5V
A7 | 2 15| A6
CLK4| 3 14| A5
NC | 4 13| A4
CCLR| 5 12| A3
SIN | 6 11| A2
|CE | 7 10| A1
GND | 8 9| A0
+------+
| Pin number | Name | Direction | Description |
| 1 | GND | - | Ground |
| 2 | A7 | Input | Address A7 |
| 3 | CLK4 | Input | Clock (4 MHz) |
| 4 | NC | - | Not connected |
| 5 | CCLR | ? | ? |
| 6 | SIN | ? | ? |
| 7 | /CE | Input | Chip enable |
| 8 | GND | - | Ground |
| 9 | A0 | Input | Address A0 |
| 10 | A1 | Input | Address A1 |
| 11 | A2 | Input | Address A2 |
| 12 | A3 | Input | Address A3 |
| 13 | A4 | Input | Address A4 |
| 14 | A5 | Input | Address A5 |
| 15 | A6 | Input | Address A6 |
| 16 | +5V | - | Vcc |
Investigation
- http://amstradcpc.mforos.com/305097/7723493-que-hace-exactamente-el-chip-acid-de-los-cartuchos/ (Spanish language)
- http://v3.espacenet.com/publicationDetails/biblio?CC=GB&NR=2243701A&KC=A&FT=D&date=19911106&DB=&locale= link to a patent rumoured to be ACID's patent.
