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Newsgroups: comp.sys.nsc.32k
Subject: Re: Now, where was I?
Message-ID: <9012191836.AA00944@halsoft>
Date: 19 Dec 90 18:36:25 GMT
Sender: news@daver.bungi.com
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My 2 cents:

>My 2 cents:
...
>> My original idea for the floppy controller was:
>> 
>> - some micoprocessor with at least 2 DMA channels (one for SCSI, one for
>>   anything else)
>> - DP8490 SCSI interface chip
>> - DP8473 floppy disk controller
>> - some static ram
>> - some EPROM
>> - a serial port (optional, but nice to have to talk to ROM monitor)
>> - a parallel port (cause everyone wanted one)
>> - some DRAM (I'd drop this now, since SRAM has gotten so cheap
>>   and is SO easy)
...
>> The piece that I never resolved was the processor. Some possibilities:
...
>> - HD64180 (or Z180): has DMA and serial channels on-chip, but basically
>>   a dull, obsolete part (64K address space with simple MMU).
>
>But fast enough if programmed in assembler.
...
>> - 80188/80186/V50/whatever: plenty of on-chip peripherals, but that
>>   $#@ Intel architecture

Don't worry about that.  This has all been beaten into some semblance of
order by a lot of very expensive programming talent at MicroSoft and
Borland.  I've been working on a fairly large 80x86 programming project
and I haven't had to deal with any of this stuff; it's all hidden by the
C compiler.  I think your best bet is to use the cheapest version of
the 80x86 family you can get - probably an 80186.

Stay away from the old 8080/Z80 architecture.  It doesn't support an
efficient C compiler, so you'll have to write everything in assembler.

Good Luck:

Jonathan Ryshpan		<...!uunet!hitachi!jon>