Sridhar Ayengar wrote:
That's really strange, because 3M and Scotch are the same company.
Peace... Sridhar
-----------
Billy:
3M manufactured for dozens of companies. They would make bulk tape (usually
18" wide) for almost anyone, including the 3M and the Scotch brand name.
Many companies would supply the formula for the binder, oxide slurry, and
suface coating.
So even though the tape came from the same production line on the same day,
it could be radically different.
3M was excellent about controlling the IP. So even though they made tape to
spec for a competitor, the detailed data would not reach their brand name
group.
At one time in the late 60's I visited their production line. They claimed
that they were making 90% of all the .5" tape on the market at that time.
Billy
>
>Subject: Re: Hand-rolling a CP/M machine
> From: woodelf <bfranchuk at jetnet.ab.ca>
> Date: Wed, 25 Apr 2007 15:23:36 -0600
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>Ethan Dicks wrote:
>
>> With as fast as CMOS ROMs are today, why not use a 27C64 and burn your
>> own charset to it? It's not tough to do, but is there a technical
>> reason it wouldn't work?
>
>That works but to find the PROM data you have to look at some very old
>memory data books. I have yet to find any nice 8x11? fonts that fit
>in a 9x12 character block could be copied.
>
>> -ethan
Motorola, Signetics or SMC databooks from the 80s.
Or do what I did back in the hazeltine days, graph paper and a book of fonts.
Allison
>
>Subject: Re: Hand-rolling a CP/M machine
> From: Warren Wolfe <wizard at voyager.net>
> Date: Tue, 24 Apr 2007 15:36:14 -0400
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On Tue, 2007-04-24 at 12:01 -0400, Ethan Dicks wrote:
>
>
>> Right. That much I get... so once CP/M is running, it's ordinary not
>> to refer to the boot ROMs? There's typically not a requirement to
>> keep some low-level BIOSy stuff in ROM?
>
>
> No, there is no requirement to keep ANY ROM available after boot.
>It is preferable, in most cases, to have the entire address space made
>up of RAM once the system is actually running, as opposed to booting.
>Some cases involve copying the ROM contents to RAM during boot, and then
>disabling ROM. Again, as has been implied, EVERYBODY chose their own
>method -- some were better than others, naturally enough. As a matter
>of fact, for those systems which implement ROM at 0000 for booting, the
>ROM *MUST* be disabled for any even half-way normal CP/M system to run.
>(See the previous discussions on CP/M for Radio Shack Models)
Basically I like to call it this way.
CP/M doesn't care how it gets there, only that it does.
>> Right. I know that there are *many* CP/M hardware configurations; I
>> am trying to get down the nub of as minimal a hardware design as
>> possible.
>
>
> CPU, 64k RAM, disk(ette) controller, ROM able to be disabled (could
>be on controller), serial port. Anything else is gravy.
>
I'd simplify diskette controller to mass storage (any form).
>> Sure. For the minimal system I have in mind, I'm planning on a VT100
>> or some modern machine running a terminal emulator (Kermit, et al.) to
>> handle screen formatting.
>
>
> Perfect.
Yep. Works well enough.
>> > A video card will chew up valuable RAM, and many of them are only 16x64,
>> > but it does let you do real-time screen updates, games etc.
>>
>> Ah... now we are onto something - games... are there many games for
>> CP/M that require a video card, or were most happy with whatever sort
>> of TTY-type device (ANSI codes or not) was out there?
>
> Video card manufacturers often produced games. Probably the most
>common target video card was the VDM-1 card, as in the Sol-20 by
>Processor Technology. I have one of those cards in my IMSAI. 16x64,
>and takes up 1 K of memory. I've seen boots that involve a VDM-1, and
>one 2708 (1K EPROM) that leaves 62K for RAM, and uses the VDM-1 memory
>for stack during boot, IIRC. Ugly, but it works. VDM-1 cards require
>S-100 bus, or massive hacking. That makes them, probably, outside the
>parameters of the "quickest and cheapest" setup you've set.
the logic for rolling your own VDM1 equivilent is 1K of ram in the
address space and a screen refresh (H and V timing, line counters)
are about 10 or so TTL peices. It's actiully simple if you do not
have to build a S100 bus interface. You can copy the screen logic
for TRS80 as that is a basic 64x16 as well.
Real time updates are possible as the refresh/scan logic keep the video
going and the CPU does the memory updates for games.
Allison
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Time to kill of the CP/M thread !
( just kidding, I am still wanting to build a junkbox CP/M system ..)
Our IT department has been cleaning out :
Next to stuff I do not find interesting ( Sparcstation 20, ultrasparc
5, DEC 3000) there was a uvax 3800, with 2 expansion cabinets.
I first saved the QBUS scsi controller (cqd-223/tmj)
Then common sense went down the drain and I set aside the uvax itself.
Now which disks would be worth saving ?
(Many RZ-28 in their own cabinet ,and 2 each of RF31, RF71, RF72 )
Should I bother at all with the RF-drives, or just go SCSI only ?
Jos
( stuff located in Zurich, Switzerland )
This is just a quick reminder that VCF Midwest 3.0 is scheduled for July
14-15 at Purdue University in West Lafayette, Indiana. Our esteemed Pat
Finnegan is again the prime mover and shaker behind the largest
extravaganza Indiana has seen since Farmer Ted in Baxton pulled a plow
clear across his cornfield with his teeth.
There is a possibility of having a working IBM 129 punch and 082 sorter
combination at the event. They are currently located in St. Louis, MO. I
am starting to investigate the logistics of hauling them the 272 miles
>from St. Louis to West Lafayette. Is anyone willing to participate in
this utter folly? If so, you get to punch the first card at VCF East 3.0!
Please e-mail me directly if you want to help with this. After the event
they'll be heading out to California to join the VCF Archives.
Upcoming VCF events worldwide:
VCF Europa 8.0 - Munich, Germany THIS WEEKEND!
VCF East 4.0 - Wall, NJ June 9-10
VCF Midwest 3.0 - Purdue University, Indiana July 14-15
VCF 10.0 - THE BIGGIE: you won't want to miss this one... November 3-4
For a complete schedule of upcoming VCF Events:
http://www.vintage.org/events.php
Thanks!
--
Sellam Ismail Vintage Computer Festival
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Someone in Colorado Springs is offering up a nice Heathkit H89 system with
dual floppies and a printer and probably some manuals and software for the
cost of shipping.
First responder gets the contact info.
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
Does anyone have or know where I can get schematics for the Gridcase 1535?
Please reply directly if you can help.
Thanks!
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
I've read the reviews of the HP 16C online for a long time, and people
are always singing their praises.
When I'm writing assembler, I always have my HP 28S within arm's reach,
and I definitely see its value. Does anyone have information regarding
features present in the 16C that aren't present in the 28S?
(I already know about the features that are present in the 28S and not
in the 16C.)
Thanks.
Peace... Sridhar
