< WIRE_WRAP!?!?!?! ICK! I usually pull out my cheapo PCB CAD program....
< A little laser-printer transfer plastic and an exacto-knife.
the best you can do with that is two sided and that might run at 25-40MHz
and that's pushing.
< I cannot believe that there can be so many extremely complex processors
< there running up to 667Mcyc (Alpha) and there not be any simple controll
< with far less transistor counts that match or exceed those speeds.
< There is no way we can get 600Mcyc clock speeds out of a 10,000,000
< transistor chip but can't get at least that out of a 100,000 transistor
< chip.
It all that complexity that permits parallelism of functions. The simpler
machine are limited by the very direct and limiting propagation delays of
gates.
< As for the Z-80 vs Alpha features.... I like:
<
< 1) I/O ports. I hate the memory map stuff. (yes, I know it is the wa
< things are done now)
Memory mapped ops even with Z80 allow you to do things like OR data with a
device or AND data from a device or use the BIT ops to test a bit in the
device. None of which the IN or OUT can do directly.
when you only have 64kb memory mapped hurts some. When you have 4Gb
so what if you give up a meg to memory mapped IO.
FYI the PDP-11 is also memory mapped and uses it to very good advantage!
< (((((((THE Z-BUS!!!)))))))) (not the Z380 bus, that's almost as hosed a
< the Alpha bus).
< Do the Z-80 bus but with the data size control lines that I explained
< above.... (or keep a 64 bit data bus and run a local bus into a 'DMA' (f
< a lack of a better word)... Wait! A bus mastering device!!!! (<-- bett
< word).)
Zbus give advance status of the transaction to occur, that information is
handy for tweeking the memory to make it get there in time instead of
wait states. Z80 bus has a high bus bandwidth and poor bus utilization
and this shows up when you have DMA peripherls.
I'm not bombing z80, I happen to like it and have used it for 20+ years!
I'm realist enough to know it's limitations and weaknesses and I can
understand why the z380 is the way it is. Personally I happen to like
the z280 as the user/system spaces make the 64k limits far easier to
work with and also offers some speed with the 16bit bus, cache and a
paged MMU while not locking the bus. The Z180 is a good compromize and
easy to work with at low speeds, at 20+mhz it's a bear as the world
around it has to keep up. It's not like using the z80 at 4 or 6mhz
any more when you notice that the decoding dealys and the buffering
delays are are a significant part of the system timing.
Allison
A while back, someone posted a great source for used and out of print
books. I've lost the URL and can't remember the name - could someone please
repost it?
Thanks
R.
--
Warbaby
The WebSite. The Domain. The Empire.
http://www.warbaby.com
The MonkeyPool
WebSite Content Development
http://www.monkeypool.com
Once you get the nose on, the rest is just makeup.
>> But after all where is the sense of having a Z80 as 64 Bit
>> processor ? It's a well usable 8/16 Bit processor. Even the
>> 380 isnt realy an advantage - you just don't realy need this
>> 32 Bit instructions. A set consecutive 16 Bit instructions
>> can do it in almost the same time. From my point of usage
>> a 16 Bit uP is anything you need - compact code, compact data
> Well, it might be fun to redo TRS-80 Level I BASIC with 32-bit
> instructions. (No way would I try to do that with LDOS/LS-DOS --
> it's already perfect).
But just tell me where 32 Bit instructions can be usefull ?
In fact, I can't think of any part inside a BASIC. But the
higher clockrates are a nice thing - and maybe the z180 for
3.0 style bankswitching.
BTW: LDOS - I have a Modell III with external HD - hasn't
there been an LDOS to boot from ? (I'm not the deep TRS guy).
Gruss
H.
--
Ich denke, also bin ich, also gut
HRK
>> Linix is free, but it still costs money.
>> You need a computer, need a CD, need other HW.
>> You need a Distribution CD
>> And a little time.
>> Shure, you can just get it over the Web ... and pay $$$
>> just for transmission ... and the needed time.
>> And after thet you need time to install ...
>> TIME IS MONEY.
>> Linux is free but not without cost.
> ** OR **
> You could get someone to burn you a CD copy, or find someone willing to
> give away their old distribution CD. I was able to get a copy of RedHat
> 5.1 burned for $5. I'm sure you could find someone fairly easily who
> would do something similar.
> I ran across a web page that listed people with old distribution CD's who
> would either give them to you or let you borrow them.
What I want to point out is that the price of
a OS isn't just the package you buy at a shop.
It's about the time you spend in installing and
trying and reconfiguration etc.
So, to come back on topic, the best for a TRS-80
emulator is still DOS. Install it, or even boot
>from a Disk. You could even put the emulator
and DOS and some TRS-Apps on one 1.44 bootdisk.
And best of all - Disk access will be Disk access.
Gruss
H.
--
Ich denke, also bin ich, also gut
HRK
>> Actually, Tim Mann's TRS-80 page is where I got the disk images. I was
>> going to get xtrs, but I don't have Linux (nor do I have the money to get
>> it). I have an emulator that'll run in DOS, but won't recognise the file
> Linux? Money? Heheheh. What stone have you've been hiding under junior?
> LINUX IS FREEE, MAN!
Linix is free, but it still costs money.
You need a computer, need a CD, need other HW.
You need a Distribution CD
And a little time.
Shure, you can just get it over the Web ... and pay $$$
just for transmission ... and the needed time.
And after thet you need time to install ...
TIME IS MONEY.
Linux is free but not without cost.
Gruss
H.
--
Ich denke, also bin ich, also gut
HRK
Its funny, I read through the list, crossing my fingers and hoping for a
PDP-8 core stack, and 90% of it is PC junk. Then I kind of laughed because
of course that stuff will probably be "collectable" for my daughter.
Assuming she decides to collect computers. Although if history is any
measure then she'll probably collect Pentium II machines since that will be
the "hot" machine that she can't afford (stuck with a measly 75Mhz P5 :-)
Another factiod registered which is PC collecting is going to be *much*
more of an art than say mini-computer collecting is because the technology
is changing soooo quickly. In case you haven't noticed there is a certain
temporal component in the PC compatible space where the hardware, and more
importantly the software, are tied together at their release dates. "Visual
BASIC, Win 3.1, Borland C++, 486/66" they make a set. Use this stuff on a
Pentium and it won't use half the features, use it on a 386 and it won't
run acceptably. And how "long" was the 486 PC window? Perhaps 3-5 years?
Compare that with the utter contempt with which people treat 486
motherboards (3 for $5.00 at Weird Stuff Warehouse) and you realize that
these things are headed for landfill big time. Along about 2010 or 2015 and
trying to put together a representative 486 system from the "early 90's" is
going to be damn near impossible. Look at the PDP-8's which spanned 15
years of production and are now pretty difficult to get hold of.
I don't know if I should laugh or buy an old Dell 486 box and wrap it up in
plastic and dessicant and save it for 20 years.
--Chuck
I'm searching for a TRS-80 emulator for the Model III. I need it to be
able to use disk images (such as LDOS), and boot from them.
ThAnX,
--
-Jason
(roblwill(a)usaor.net)
ICQ#-1730318
PS>> The only reason that I need the emulator is to make LDOS, and a few
other programs for the Model III - not to imitate having an actual III :^)
Sounds like they have buying power greater than Wal-Mart's to offer such
pricing. Either that, or they have exclusive rights to manufacturer or
publisher overruns or defects.
Jeff Salzman
------------------
"If Taelons had hair, would Du'uh be a blond?"
>Haven't all you hard-core Linuxers bought from www.linuxmall.com yet? I
>have paid $1.49 for CD's of the last 6 distributions I've used. They also
>sell major applications (Word Perfect, Star Office, Applixware) for less
>than the source vendors. I think I got the Applixware student version for
>~$50 a couple of years ago. Oh yeah, they also sell Oreily books cheaper
>than Oreily...
>
>While I don't regret rescuing this stuff, I have no clue how long it will be
>until I could ever power this stuff on. The Hut has its own 60 Amp feed
>seperate from the house, but 110/220, no three-phase power. I suppose I
>could purchase/rig-up a 220V<->3Ph mechanical converter,
You don't need three-phase for the equipment you got - if you look at
the DEC power controllers, they just split out the three phase into
three 120VAC circuits which power the individual boxes. Especially
as you have MOS instead of core memory, 30 Amps will be plenty for a CPU,
memory, and a couple of Fuji Eagles.
Some big Massbus disks (and their Memorex and CDC mechanical equivalents)
do need three-phase for the drive motor, but I didn't see these in your
list.
>P.S. ISTR that PDP-11/70's and VAX-11/750's use the same hex-height 39-bit
>ECC memory boards. Is this true?
Assuming you have the DEC MK11 memory boxes, yes this is true. There
are also third-party memory boards available for 11/70's; my favorite
are the board sets that pop into the 11/70's backplane and give you
4 Megs of cache memory, so there's no need for memory boxes!
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology Voice: 301-767-5917
7328 Bradley Blvd Fax: 301-767-5927
Bethesda, MD, USA 20817
