TEK - PS/2 to Matrix Keyboard Adapter/Emulator

I've recovered the tree of files with the SDCC compatible firmware.

Sorry, uploaded wrong files to dropbox, but removed them already.

After receiving feedback of Joachim from ZX81 user group that assembled the TEK I've started to porting the code to SDCC. At this time I can compile the code in SDCC running under Windows. On Linux I am still dealing with some compilation errors related to libraries but this is a matter for another log.

The porting basically required:

• Installing the necessary tools

1. SDCC
2. GPUTILS

• Changing the type of some variables to be compatible with SDCC: chars have been replaced by uint8_t to avoid warnings and int1 have been replaced by uint8_t. I've tried to use _Bool type (from stdbool.h) but this resulted in an internal SDCC error!

• Changing the way of defining the fuses

//#fuses INTRC_IO, NOPROTECT, NOBROWNOUT, NOWDT, PUT 
uint16_t __at _CONFIG configWord = _INTRC_OSC_NOCLKOUT & _CPD_OFF & _CP_OFF & _WDT_OFF & _PWRTE_ON; 

• Replacing library functions by macros or direct accessing the registers.

// output_low (PIN_SDA);

TRIS_SDA=0; //set as output
PIN_SDA=0;

• Changing the delay_us funcion to reflect the time spent by the assembly code generated by the macro (it takes 4+ 9*X cycles).

#define delay_us(x) {  uint8_t us;	\
      us = (x)*FOSC/36000000L - 4/9;\
      while(--us != 0) continue; }

The SDCC compiler provides an estimate size of code generated: 669 instructions.

It is almost the same size of the code generated with CCS. The difference is minimal.

Added connections for ZX81/TK85 and key bindings for PS/2 Keyboard (ABNT Standard). Will update firmware link as soon as new bindings for keyboard is set.

Further details available here.