Bootstrappable language

bfranchuk at bfranchuk at
Thu Dec 11 13:27:12 CST 2008

Dave Dunfield wrote:
> You don't need register to register operations to support a C compiler.
> Can you provide any details of your architecture and instruction set?
> It might be feasable to make a port of my Micro-C toolset to it... If
> not, it might be feasable to make a port of "C-flea" a virtual machine
> I designed specifically to support Micro-C (I've supported some pretty
> weird architectures by employing C-flea).
The architecture is like I said before a stretched PDP-8, with a
512 byte  direct addressing range and more compleate set of alu operations.
I am exploring the idea that 18 bits is still the best size  word size 
for a small
computer or  digital  controller. The extra opcode bit  is used to 
support word &
byte sized operands, compared to the that of a 8 bit micro. The two more 
bits negate the loss of byte addressing and give a bit more room for a 
OS rather than swapping core in and out.

Using CPLD's also gives me the feel that a 18 bit simple cpu like my design
could have been developed as microchip computer similar to 6800 or 6502
chip set around the time the Z80 was developed. Using 48 rather 40 pins
as packaging a 18 bit cpu with front panel support could have been 

A) Cpu chip.  B)  Swr/data/address bus display support chips . C)  
data/byte swap buffer.
> Micro-C is a very small, but reasonably powerful dialect of C - For an
> example, refer to the ImageDisk sources on my site ... ImageDisk and all
> of it's utilities are compiled with the PC version of Micro-C (as are my
> simulators, transfer tools and pretty much all of the other DOS based
> tools I've posted).
> Dave
> Btw: If you haven't written an assembler yet, let me know - I've got a
> universal table driven assembler generator which I developed to rapidly
> produce assemblers for many of the later architectures I supported.
Unlikely it will work ,  I have 9 bit bytes.
I have hacked, Jones's PDP 8 assembler to cross assemble for me.
Once I get the the single PCB board built later next year, then I
will consider porting Micro-C. I plan to only have about 64Kb +
bootstrap EEPROM, IDE interface and a two 6850 uarts
along with a front panel. I am not sure yet if the IDE interface will be 
16 or 9 bits wide yet.

> --
> dave06a (at)    Dave Dunfield
> dunfield (dot)  Firmware development services & tools:
> com             Collector of vintage computing equipment:

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