Schematics for the Datapoint 2200 processor (version 1, serial) transcribed from original documents. Also contains various original documents.
The schematics are in Kicad 5 format. To open them you will need to import the symbol library in Datapoint2200.lib.
NOTES:
- These documents are still a work in progress.
- Schematics have not been double checked or verified against original hardware.
- On the original schematics some of the connector pinouts are ambiguous. DO NOT rely on the data in this repository when working with original hardware.
- 2200_Drawing_package.pdf - Original schematics and engineering drawings.
- 2200_Reference_Manual.pdf - The original instruction manual including the assembly instruction set.
- Datapoint2200.lib and .dcm - Kicab custom symbols (for Kicad 5).
- InstructionSet.txt - The instruction sets for both versions of the 2200 and the (very similar) Intel 8008.
- InstructionSet.xlsx - Spreadsheet version of the instruction sets (2200 and 8008) including comparisons against the Z80/8080.
Schematics for each board are in a separate folder.
The following lists the key boards of the Datapoint 2200 and the files making up each board.
Board A4: This board generates the system clock, T-states and various processor/system timing signals, does I/O decoding and generates the sound signals to be sent to the speaker.
- Decoder: The main overview.
- IODecorder: Output signal decoding.
- Scheduler: System clock and timing signals generation.
- Speaker_Tape: Sound generation and misc tape signal logic.
Board A7: Driver for the CRT gun and it's X/Y co-ordinates. Not transcribed.
Board A3: Demodulator for the tape drives Not transcribed yet.
Board A8: Video memory, character generator and display driver. Not transcribed yet.
Board A5: The keyboard Not transcribed yet.
Board A9: Logic for the keyboard (i.e. the I/O handler). Not transcribed yet.
Boards A11-A14: The shift memory cards Not transcribed yet.
Board A2: Modulator for the tape drives Not transcribed yet.
Not transcribed yet
Board A1. Not transcribed.
Board A5: The processor itself.
- AddressRegister: The address register (counter).
- AddrRegAndStackControl: Controls reading data into the address register and program counter, incrementing the program counter, and the stack.
- ALU: The ALU and carry flag.
- ARegister: The A register and I/O bus.
- Flags: The flags (other than carry) and conditional jump/call/return handling.
- InstrDecdoing: Instruction decoding.
- IRegister: The instruction register and register decoding.
- Processor: The main overview.
- Registers1: The H and L registers and data bus logic.
- Registers2: The B, C, D and E registers.
- Stack: The stack and stack pointer, and memory card selection.
- Timing: Fetch-execute cycle, memory word sync, HALTing and running, clocking and miscellaneous.