Holy Crap! IMSAI's weren't this expensive when new!

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Sat Feb 10 14:11:58 2001

From: Richard Erlacher <edick_at_idcomm.com>
>0xE000 that puts an upper limit on the TPA. Memory mapping the FDC was,
>from what I observed back when it was relevant, just about the most
stupid,
>Stupid, STUPID thing one using a Z80 could do. It helped nothing, save
>perhaps some wiredosity of their equally silly choice to use
hard-sectoring,


Your applying 2001 logic to a design that was complete in 1976. In 1976
do you think you could do better and cheaper?

If you say yes remember I have icom fdos and also worked with TRS80
and NONE in 1977 had anything near that for the same or similar bucks.

>them, AND, considering when they came out with it, it prevented the
average
>user from utilizing the more popular software packages, which, because
of
>the timing, were too large to run in the small TPA. Remember, they
wanted


Never prevented me from running ANY of them with a 56k tpa. Most ran
well
in 48k. The only one that wanted a larger TPA then 48k was SMALLC V2
compiler as the optimizer wanted more space.

Lessee by 1981 64k of ram was still around $499 for dynamic and static
was about $600 so there were people that weren't into the must have a
full box to do things.

>their customers to run NDOS, not CP/M, and CP/M required a contiguous
memory


No they would later support and implement CPM. They also had in 1978
UCSD
Psystem with Pascal for $50 (bargan in my eyes). NSDOS was a far lower
cost
(both in footprint and $$$) OS than cpm and unlike cp/m came with a
decent
interpreted disk basic. The closest thing to that cost 150$ for CP/M and
$$350
from MS (disk basic, compiler was $500).

>span up to the BIOS. The BIOS itself, of course, could use memory ABOVE
the
>controller and EPROM if there was any. Of course, NorthStar didn't
support
>that solution. At the time, if you had an application that was coded
in

They didn't have to support it and for many that was not a requirement.

>MT+, which was VERY popular at the time, it required at least a 56K TPA.


>Now, the TPA was the part of memory that lay BELOW the BDOS. If you
load


TPA was the space BELOW THE BIOS and E7FFh is 59k into a possible 64k!

>something at 0100 and run it up to 0xE000, there's no room for BDOS or
BIOS.
>That's why, at that point in time, until later when the popular
compilers
>were rewritten to support overlays, machines like the NorthStar and some
>from Vector Graphics, both of which were famous for their small TPA's,
were
>pretty much useless.


Your saying I didn't run MS basic-80 compiler, smallc, TurboPascal, BDS-C
Cbasic, Multiplan, Dbase then? Oh thats right it was not doable. Most
of that
stuff only wanted 48k though it ran well on my 56k system.

>Well. not exactly. If you didn't mind that you couldn't use anything
but
>NorthStar-formatted media, you could survive, but there was no chance at
all
>of having any media interchange with anyone without a NorthStar
controller.


Prior to about 1982 that was not only not an issue it was irrelevent.
Back in
that era running softsector was often not much help as everyone ran
something
different format wise.

>I bought three NorthStar systems for $1 each and donated them to the Boy
>Scout troop a friend of mine was running back in '80. The complaint
with
>which I got them was that there was no way to use them because the TPA
was
>too small and because you could not read standard media.

Thats your fault not the system. Like I said I was running 56-58k TPA
off an
unmodded copy of LIFEBOAT CP/MV1.4. When I moved to using 2.2 I
put the bios above the controller for a very nice 59k TPA with hard disk
support.

I'll agree that putting the FDC at F800 (NS offered roms for that, I have
them)
would have been more convenient but E800 was not a significant handicap.
Actually if you wanted to burn your own roms it was easy to do.

The media problem in the early 80s was not so much standard media but
the idea there was even such a thing. That would persist until PCs wiped
evrything else out now we only had 360k, 1.2m, 720k, 1.44, ZIP disk and
Cdrom to confuse the issue.

>Rememver, Allison,

>the CP/M diskette standard, and there is only one, is 8" IBM
3740-formatted
>SOFT sectored single-sided ...


Well, since I have the NS horizon I built in 1978 I dont need to
remember. I know!
Yes, 8" SSSD was the standard save for it was expensive, large, noisy,
hot
and only gave you 256k. I know, I supported it and still do. An SA801
and
controller was easily $400 more expensive in late 76! Even if you had
softsector
5.25" that didn't mean you did support 8" though many could. In 1977
NS*
it allowed people with on 16 or 32k to run Basic and a disk OS which was
a mostly useless config for CP/M. Then again in 1977(late) 32k of ram
was
around $800(kit, 900-1000 assembled and tested).

I still have a Intergrand dual 8" full height box. it's loud, noisy and
nearly
as big as the S100 crate above it. I also have a HZ-207 box with two 1/2
height 8" 2sided DC motor drives and it's still big and weighs a ton.

>> Irrelevent. He may also know that there is also very good support for
>> ^ Have you ever considered using a spell-checker?


Here we go again. if opinion doesnt work then attack the spelling.

Sorry, just like your editor doesnt support clipping off unwanted text
mine
does not support a decent spell checker (if there were one for PCs).

>really? Where?


Good support is: few of the historical systems are as to easy to find
docs,
software and working hardware for. Also if the hardware doesnt work it's
easy to repair with common ttl. It's one of the few configs that exists
20
years later as can be made to work easily.


Allison
Received on Sat Feb 10 2001 - 14:11:58 GMT