Things that might be remotely useful to some people

I2C interfacing via PC parallel port

This is my variation of the theme. It implements I2C master-mode by bit-banging a couple of lines on the PC parallel port. Includes C source portable for both Borland and Microsoft compilers as well as a PostScript schematic of the needed interface circuit. The latter is probably overly complicated, being totally opto-isolated. Designing a simpler one shouldn't be too hard.

18-Jul-95: Thanks to Ray Bellis for a bug fix involving multi-byte reads.

PC_I2C.ZIP [~40K] | adapter schematic (PDF)

EPROM emulator

A nice EPROM emulator circuit designed by me and Marko Winblad. Indispensible while debugging microcontroller software, this emulator is loaded quickly on the fly from PC parallel port and emulates chips up to 27512. The package includes schematics plus software with C source code.

READ THE DOCUMENTATION before mailing me about how to view the HP-GL file!

PROM_EMU.ZIP [~180K]

ROMable i86 code with Turbo C

These packages should be useful if you want to use your favourite DOS compiler for embedded applications. They should work at least with some older Turbo C compilers. Note that I haven't actually used either of them - please direct any questions and comments to the original authors.

If you're only trying to boot up some embedded PC application without paying any license fees to Microsoft or whoever, you might also be interested in Pat Villani's DOS-C and the FreeDOS project.

EXEHEX.ZIP [~17K]
ROMIZE.ZIP [~12K]

Table driven frame checksum algorithm

This C example posted to sci.electronics by Dave Medin way back is a very fast implementation of a 16-bit frame checksum. Properly implemented, it isn't much slower than a simple XOR sum and is very much better in catching errors. Will run efficiently on a 8051, for example.

16-bit frame checksum algorithm


[to home page]