SCSI to IDE

Tony Duell ard at p850ug1.demon.co.uk
Thu Dec 2 13:54:43 CST 2010


> 
> > I do not dispute htat. My main comment was to the poster who suggested an
> > ARM-based microocntroller (I have never seen seen such a device in a DIL
> > package)
> 
>     There are always SMD to DIP adapters :)

Which normalyl cost more than the chips to put on them (at least in the 
UK).

> 
> >>     - I can design a PCB at home using free tools (Kicad rulez!)
> > For the nth time, the machien it runs on (and I susepct the OS it runs
> > under) are not free.
> 
>     A Pentium III - which you can find in trashcans - runs it with linux. 
> And linux is free :)

You keep on telling us that things are different between Brazil and the 
States, and what is common in one place is not common in the other. Whcih 
I happily accept. All I can say is that the UK is different again. Or at 
least I've enver found any form of Pentium PC for free. The latest PC 
that I've been given was a battered 386SX that, I have to admit, I took 
apart for useful bits. 

Also, not being a PC enthusiast, you have to relaise that while I would 
have things like HP-HIL keyboards and mice, HP 22kHz horizontal composte 
monitors, and the like, I do not have spare PC/AT or PS/2 keyboards, PC 
mice or VGA monitors.

> > Excellent (I am not being sarcastic). Hwoever, building that equipment is
> > a project in itself (albeit an interesting one). If you just want to make
> > up a SCSI-drive rpelacement or whatever, why should you _have_ to make
> > the PCB stuff first?
> 
>     I can always use perfoboard...or just connect the wires chip-to-chip.

Sure, do thast all the time. It's a little harder (not I did not say 
impossible, I do it all the time) with SMD pacakges though.

> > Why? As I said in anotehr message, thsi is a hobby, why shouldn't I do it
> > the way I enjoy?
> 
>     You can do in any way you want :) But when I do and for people being 
> able to reproduce it, I try to do it in the easiest way to most hobbists to 
> reproduce it. :)

I am actually wondering how on earth you can know what 'most hobbyists' 
can do, or would want to do...

> 
> > Fine. I was ismpoly pointing out that there are people who ar
> > expeerienced in (say) Z80 assemblet and not AVR. In which case, for a
> > hobby project, why not use the former?
> 
>     No problem. But why not use the later, since it is more powerful, has 

No reason, if you want to, and you have the facilities to use it. 

> more built-in things and is easier to program (not everyone has an eprom 
> programmer, emulator, eraser, etc) for most hobbysts
> 
> > Looking around, I don;t think I can see _one_ machine here that could be
> > used for that. You mention a programmer conissiting of a few resistors
> 
>     You don't have ONE PC on your home?

It is my bitter esperience that a lot of thsee parallel-port devices, 
even those that have software that runs under MS-DOS, do not work 
properly on a 4.77MHz PC/XT...

> 
> > ona a parellel port. I've  got pletny of GPIB ports here, but I guess
> > that's not what you meant. OK, what about an HP9817 with an HP98522 GPIO
> > card? It probably could program an Atmel processor, but I'll bet the
> > software doesn't exist...
> 
>     The nice thing of open standards is that you can always roll your own :)

True, and contrary to some other people here, I do like making my own 
tools, whether they be mechancial tools, electronic tools (like test 
equipment) or software tools. In fact _I_ am seriously looking at some of 
the current microcotnrolelr families for use in projects. But this 
doesn't mean everybody has to want to use them. 

FWIW, I was simply defending the right of some other poster to build this 
device using a Z80 and 8255s if he wants to. You don't like that desing? 
Well, nobody is stopping you making your own.

> 
> > OK, so firtly you have to buy this tool [1] and secondly I need a USB
> > host to control it.
> 
>     Ah, come on Tony, P3 are throwaway itens...P4 are cheap as candy. A nice 

Not round here...

> post "I need a P4"will bring 3 or 4 to your door. For free. Why not use new 
> technology? Linux drives that, you don't need to use windows. And if you get 

For mt own (in)sanity, I want to unsderstand how thigns should work, so 
when (not if) they don't I have some chance of putting them right. I 
guess that answers your question...

> > 6303 in one of its many varieants? 7811? COP400? 3870? Do I have to list
> > any more?
> 
>     Was ist common?? When?

I have come across all of those microcontrollers in my time. In fact I 
was using something based on the 3870 (the HPIL-GPIO interface) and 
reparing something containing a COP400 (HPIL knob input device -- in fact 
jsut about all HP-HIL devices have COP400s in them) a couple of days ago. 

Actually, the 8048 family is getting soemwhat hard to find now (AFAIL it 
is no longer manufactured), and that one turns up _everywhere_.

> 
> > Actually I disagree with that. It's often easier to repari something with
> > lots of parts, where yoy only have to replace the one bit that's failed.
> > Which would you rather have to fix? An HP9830 (lots of TTL), a Sinclear
> > Spectrum (custom ULA) or a modern PC motherboard.
> 
>     I can repair the three :) I can even recreate the speccy ULA in CPLD :) 

So can I. So what? Which would you rather repair?

-tony



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