"Scarletdown" <SecretaryBird(a)SoftHome.net> wrote:
> I might just build a very minimalist 386 or 486 system from spare parts
> I have lying about here, set it up with FreeDOS or MINIX, and make that
> the console. [...]
Actually the easiest way to build a 386-based terminal is with MSDOS
(or DRDOS) and kermit. Kermit supports most serial cards and even some
ethernet cards (so you can telnet over TCP/IP). There is even
DOS-based software for mouse support (so you can cut & paste text).
Kermit or DOS can take care of most input and output conversions so
you can talk to almost any system that support telnet or async serial.
BTW since most IDE disk have a spin down feature, you can spin down the disk
just after you load kermit, so you don't even have to listen to the hard
disk. Many systems of that era didn't have PSU fans, so spinning down
the disk made the system totally quiet.
**vp
> Sounds like motivation to keep a bootable DOS5 system around, with both
> 3.5" and 5.25" drives....
And don't forget to have an ethernet card, and either a copy of PCTCP, or
anotherbootable OS on the system that has a TCP stack. One of these days
I'm going to build such a system. I've managed to collect all the parts,
and even a nice small PC, I just haven't found the time (or really a place
to put it).
Zane
> What's to know?
Still..
> How available is it?
Dunno. Technically, I shouldn't have it, right? Then again, MS dropped
DOS quite a while ago, so... pfff... Fair Use for retro-hackers ? :)
--f
> This may have been the very first (for me at least) of the by now
> innumerable MS Gotchas
Dunno about MS-DOS V6.22; I'll look it up in the format.exe source..
(yes, we have the source, and no, we're not gonna fix it ;-)
--fred
>
>Isn't this the commercial version of the Blit?
>
Yup.
>
>Does anybody actually have one?
>
Nope. I last had my hands on one circa 1988. Never seen one on eBay...
>
>"Ken Seefried" <ken(a)seefried.com> wrote:
> My most favorite was the AT&T 5620 with a host running layers.
>
Hi there,
I have a two Epson HX20's (which we use in our reasearch lab - yes still
- to control some
equipment) one of which has sufferred a failure of the power supply on
the main CPU
board (details below) and I need to get hold of a schematic if one
exists. I beleive that Epson produced
a repair guide - does any one know where I might be able to source this
information.
I have had a plough through the archives to this list and there are some
very helpful people out there
and maybe if anyone has some experience with this machine and can give
me pointers - the following
might help ...
The batteries and external adaptor are good (new) charging correctly and
delivering 4.8 V.
However, the power switch has no effect (no LCD, no beeping)
The main power rails seem to be off - there is 4.8 v at one test point
0 at another an 2.8v scattered
around the board. There seems to be no 17 V which I beleive is needed
for the LCD.
The previous owner reported a burning smell so component failure is
suspected, but no obvious signs
on the transistors.
A previous writor in the archive (Tony Duell) suggests that a volatge
should be present on the collector of Q8,
this is absent.
Thanks in advance
Yours
Matthew Clemence
Hi,
I have here a half working Teletype ASR35. I am missing some parts, namely
the plastic hood, manuals and some lightbulbs. Also the ASR35 isn't
working properly, I am missing half of the keyboard sorta speak, you can
type uptil the letter H or so and then if you continue it starts with the A
again.
So any help with that is also welcome.
Thanks!!
Stefan.
Hi Joe:
I subscribed and posted to cctech, but found your response in the cctalk
archive. This list is new to me -- do you think I should I subscribe to
cctalk instead of cctech?
>>>I have three or four 9915s and a keyboard... I don't know what the
difference is between an A and a B model... I did make a schematic of my
keyboard but I haven't seen it in a while...
>>>
As I understand it, the 9915A is compatible with the HP-85 (aka HP-85A),
while the 9915B is an 85B. IIRC, the 85B has built-in mass-storage and i/o
roms, and more ramdisk memory than the 85A.
I'd sure appreciate any keyboard info you may run across -- I could program
a little pic to convert a serial keyboard. If this keyboard is used with
other HP machines, other folks might find an adapter handy too.
>>>You need to use the HP composite monitors. IIRC the PN is 82912 and
82913. These are used on the HP 86 and commonly used on the 9000 220 (aka
9920) and are pretty common.
>>>
>>>There were software developement kits available that let you write
programs in assembler and burn them into EPROMs that plugged into a HP-85
type plug-in cartridges (called a Hybrid ROM or something like that) or
directly into the 9915. The EPROMs that are in it are probably Matrix
and/or I/O ROM IIRC. That seems to be standard in the 9915s that I'm aware of.
>>>
Yes, I have a programmable-rom-module and assembler rom (but have not tried
them yet). A buddy of mine has managed to read 85 roms and burn them into
eproms for the prog-rom-module. The original 85 roms seem to be special,
and cannot be simply duplicated.
I opened up a rom, hoping to find a standard package, but found a chip
covered in a blob of epoxy, attached directly to a small board. I opened
the rom drawer card, and found that all six sockets are wired in parallel
(no individual enable lines to each). Then I looked at the signals
connected to the rom card connector (using the serial manual's connector
pinout as a reference). The roms have +12V, +6V, and -5V power. There is
an 8-bit bi-directional bus, and four non-overlapping 12V clock signals.
There is a "load-memory-address" line, a "power-on" line, "read" and
"read-control" lines, and even a "write" line (I don't know why write is
available on a rom).
This all leads me to believe the roms are pretty specialized. Since there
are no lines to enable a specific rom socket, I think the 85 must poll for
roms using fixed address ranges or something -- this implies that the roms
contain address qualification circuitry of some sort. I'm just
speculating, but it would make the roms very difficult to duplicate, since
this is not a standard address-bus/data-bus (or even a typical multiplexed
addr/data bus).
Thanks for the info Joe,
gil
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