Datel Action Replay PC

===PCB components:===
Name	Type 	Manufacturer 	Name/Value 	Pins	Info 	Notes
U1 	EPROM 	National Semiconductor	NM27C010 	32 	datasheet	
U2 	Dual Flip-flop 	 	HC74A 	14 	datasheet	
U3 	SRAM (8KB) 	Hyundai 	HM6264ALJ-10 	28 	datasheet	8 Kilobytes (8K words by 8-bits), 10 nanoseconds
U4 	SRAM (128KB) 	Hitachi 	HM628128LFP-7	32 	datasheet	128 Kilobytes (8K words by 8-bits), 70 nanoseconds. 
L=low standby power (10 uW)
U5 	555 Timer 	STMicroelectronics 	NE555 	8 	datasheet	
P1 	Programmable Logic Array	AMD 	PALCE20V8Q 	24 	datasheet	The part number "PALCE20V8Q" decodes as:
20 inputs, 8 flip/flops or outputs, Quarter power (55 mA Icc)
P2 	Programmable Logic Array	AMD 	PALCE20V8Q 	24 	datasheet	The part number "PALCE20V8Q" decodes as:
20 inputs, 8 flip/flops or outputs, Quarter power (55 mA Icc)
P3 	Programmable Logic Array	AMD 	PALCE20V8Q 	24 	datasheet	The part number "PALCE20V8Q" decodes as:
20 inputs, 8 flip/flops or outputs, Quarter power (55 mA Icc)
P4 	Programmable Logic Array	AMD 	PALCE20V8Q 	24 	datasheet	The part number "PALCE20V8Q" decodes as:
20 inputs, 8 flip/flops or outputs, Quarter power (55 mA Icc)
C1 	Capacitor 	 	 	 	 	
C2 	Capacitor 	 	 	 	 	
C3 	Capacitor 	 	1 uF / 63v 	 	 	
D1 	Diode 	 	 	 	 	
D2 	Diode 	 	 	 	 	
R1 	Resistor 	 	23k Ω 	 	 	
R2 	Resistor 	 	100k Ω 	 	 	
R3 	Resistor 	 	1K Ω 	 	 	
J1 	Connector 	 	DB-9 male 	 	 	
===Dip Switches / Jumpers:===
The right 3 switches on the dip switch block (S4-S6) control the ROM address, while the left two switches control the IO port. S3, the third switch from the left, is not explained. 
The 6 jumper pins at JP1-6 are used to set the IRQ. A vertical pin closing the top and bottom contact selects that IRQ 
The manual lists the following values: 
ROM Address
S4 	S5 	S6 	Address
UP 	UP 	UP 	DC00h
UP 	DOWN	DOWN	D800h
DOWN	UP 	DOWN	D400h
DOWN	UP 	UP 	D200h
UP 	UP 	DOWN	D000h
DOWN	DOWN	UP 	CC00h
UP 	DOWN	UP 	C800h
DOWN	DOWN	DOWN	Unspecified (TODO: test)
IO Port
S1 	S2 	Port
UP 	UP 	280h
DOWN	UP 	290h
UP 	DOWN	2A0h
DOWN	DOWN	2B0h
IRQ
JP1	JP2	JP3	JP4	JP5	JP6
2 	3 	4 	5 	6 	7
===Firmware===
The firmware is 128 kilobytes, separated into 16 8KB Pages.
Each page begins with a header that says which page it is, and mentions "(c) 1993 DATEL"
The AREPLAY.COM file has error strings for "Action Replay ram not switchable" and "Replay base address is not being shadowed" which suggests the larger SRAM chip (U4) is being used to shadow the EPROM at runtime. 
There was at least one upgrade to the EPROM provided, which involved mailing out a replacement chip to users. 
===Anti-virus functionality===
The firmware contains the signature of 50 viruses, starting at offset 0x164D8. 
Each name is proceeded by an 0xFE character, can be up to 26 letters long, and is padded with spaces. 
===IBM Control===
The external "paddle" features a button, switch, and LED. The PCB inside calls it the "Datel IBM Control" 
DB9 (female)
 	Connection	Color
1 	N/C 	N/A
2 	LED 	Brown
3 	Switch 	Black
4 	Button 	Blue
5 	Ground 	Green
6 	N/C 	
7 	N/C 	Yellow
8 	N/C 	
9 	N/C 	
Shell	N/C 	Orange
===Credits:===
The firmware contains credits at offset 4F64: (TODO: See if you can view this from within the program)
                  Action  Replay  v1.3         (c) 1993 DATEL
           Programmer ............................ Simon P.Constable
           Project Manager ......................... Wayne H.Beckett
           Design ................................... Mike J.Connors
           ......................................... Wayne H.Beckett
           Hardware .................................. Roy C.Harding
           Support .................................... Mark Wallace
           .......................................... Damon P.Barwin
===Twitter Threads:===
*When the Brandon unit first showed up on ebay (April 24th, 2019)
*In response to the LGR video (February 21st, 2020)
*Firmware image reverse engineering (February 25th 2020)
*Status update after the card arrived (February 27th, 2020)
===Related Links:===
*Lazy Game Reviews video on the Action Replay PC
*Manual, PCB images, and software
*VCFed thread
*Version 4 firmware dump