Bootstrappable language

[Allison]

>
>Subject: Re: Bootstrappable language
>   From: "bfranchuk at jetnet.ab.ca" <bfranchuk at jetnet.ab.ca>
>   Date: Thu, 11 Dec 2008 12:27:12 -0700
>     To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>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

Have you lookd at DG Nova?  Sounds like your traversing that same path.


>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 
>address
>bits negate the loss of byte addressing and give a bit more room for a 
>resident
>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 
>developed.
>
>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.
>

A table driven assembler can produce anything.

Also a stack based language or even C can have the anythig stack related as 
multiple instructions only code efficientcy suffers and code size.

An alternate way to go is a small emulation engine written in assebler to emulate
a easier to compiler for virtual machine (P-code).

The IDE can be 9 bits as the upper 8 (or less) bits are only used for data and a
non required ops.  I've done that for 8bits to simplify the interface and the 
only cost is 50% of the data space was not used, a minor nit as I had 500% 
more than needed.


Allison