13 Sep
2005
13 Sep
'05
5:06 p.m.
I saw an auction which reminded me of the days when the PC and XT
came out, but before clones or otherwise appeared, and before such
as AST were dominating the market.
This auction is for a "zukerboard" 576K mem expansion. 6801436037.
I remember the hype for zucker that they were going to wreck the
market.
The only reason this has any significance is that I believe this was one
of the
AST wannabe's, or even was larger than AST, pre the days when they
started making systems.
I know of at least Zucker, Tecmar (marty tech, I don't remember marty's
last name, but he was some sort of PHD ohio type, I think).
A number of companies were based here in Orange County, California,
and provided a lot of cheap stuff as they cratered, and the local
scrappers
got their. stuff and sold it off.
Processor Technology (? I think) went big time and cratered.
I remember a little shop here in Santa Ana which had the first clone of
the IBM PC. It was a single board which had 640k memory, allowed
using 64k memories, instead of the 16K memory that the PC and XT
earlier models used.
It was called "Superboard" and was no relation to Supermicro, which
came much later. It had a bios that usually worked, but also had,
conveniently, a spot for up to 6 eprom chips, so you could put in a
PC bios if you could get a copy.
The PC used either EProms, (16K I think) and the Roms that were
shipped with the BIOS were registered. The standard Data I/O would
not read them since they were not programmable, and needed their
output enabled to read the data.
But once someone had them in the 2716's, it was easy to get them
running in your superboard.
First systems had a 63 watt P/S, and IBM cards if you could find
them for video. Also there was no floppy controller on the first
board.
Maybe others of you can recall expansion card makers, of such
things as serial, parallel, memory, floppy, then hard drive, etc.
Jim
13 Sep
13 Sep
4:45 p.m.
I remember a little shop here in Santa Ana which had
the first clone of
the IBM PC. It was a single board which had 640k memory, allowed
using 64k memories, instead of the 16K memory that the PC and XT
earlier models used.
DId any IBM PC/ST motherboards use 16K DRAMs. Yes, I know the standard
memory mapping PROM could be set up to use 4 rows of 4816s (64K o nthe
mainboard), but did IBM ever do that? There's no mention of it in my TechRef.
The PC used either EProms, (16K I think) and the Roms
that were
shipped with the BIOS were registered. The standard Data I/O would
Do you mean there were internal data latches in the IBM ROMs?
not read them since they were not programmable, and
needed their
output enabled to read the data.
But once someone had them in the 2716's, it was easy to get them
running in your superboard.
Surely it was trivial to use DEBUG or similar to dump the appropriate
area of memory to disk...
First systems had a 63 watt P/S, and IBM cards if you could find
them for video. Also there was no floppy controller on the first
board.
AFAIK, no IBM PC, PC/XT, PC/XT-286, PC/AT, or PC-jr had a floppy (or hard
disk) contorller on the mainboard. None had parallel ports either, and
the PC-jr was the only one to have video and a serial port on the mainboard.
-tony
5:45 p.m.
Tony Duell wrote:
You may be right, I think due to fog bank between ears that it was 16k in
apple ][ then 64k in original xt, then 256k in the superboard.
Yes, as I understand it and saw, the roms could be enabled, using a
line that the data I/O didn't drive (29b variety any did not). So you got
FF out when you read them.
Yes the dump was trivial, but the R232 or other to an eprom programmer
was not.
I had no RS232 or computer driven eprom programmer till much later
when the Taiwanese programmer boards came out.
Before that, I had only Data I/O 29b. Most distributors that you could
buy parts from and beg the use of a programmer could not get the data
into their programmers. So you carried the master parts and programmed
blanks. anything else was a pain.
I'm not talking about what you could do as a company with a budget. I'm
talking about what you could do in your house when Data I/O was getting
around $20000 for programmers, and $4000 for updates, and they
were about all that there was out there.
The next rev of the superboard had floppy and serial on board. First versions
just cloned the PC motherboard, including the tape interface, later deleted,
and accomodated a full 640k w/o extra boards.
I remember a
little shop here in Santa Ana which had the first clone of
the IBM PC. It was a single board which had 640k memory, allowed
using 64k memories, instead of the 16K memory that the PC and XT
earlier models used.
DId any IBM PC/ST motherboards use 16K DRAMs. Yes, I know the standard
memory mapping PROM could be set up to use 4 rows of 4816s (64K o nthe
mainboard), but did IBM ever do that? There's no mention of it in my TechRef.
The PC used either EProms, (16K I think) and the
Roms that were
shipped with the BIOS were registered. The standard Data I/O would
Do you mean there were internal data latches in the IBM ROMs?
not read them since they were not programmable,
and needed their
output enabled to read the data.
But once someone had them in the 2716's, it was easy to get them
running in your superboard.
Surely it was trivial to use DEBUG or similar to dump the appropriate
area of memory to disk...
First systems had a 63 watt P/S, and IBM cards if you could find
them for video. Also there was no floppy controller on the first
board.
AFAIK, no IBM PC, PC/XT, PC/XT-286, PC/AT, or PC-jr had a floppy (or hard
disk) contorller on the mainboard. None had parallel ports either, and
the PC-jr was the only one to have video and a serial port on the mainboard.
-tony
14 Sep
14 Sep
4:01 p.m.
Tony Duell wrote:
You may be right, I think due to fog bank between ears that it was 16k in
apple ][ then 64k in original xt, then 256k in the superboard.
IIRC, early PCs used 16K DRAMs (1 row soldered, sockets for 3 more, so
16K .. 64K on the mainboard)
Later PCs used 64K DRAMs, so 64K .. 256K on the mainboard.
PC/XTs also used 64K DRAMs, and from what I've seen all 4 rows were
socketed. There's a well-knwon modification, I am sure everyone here
knows it, to put 2 rows of 256K and 2 rows of 64K on the PC/XT mainboard
for the full 640K. This was later sort-of supported by IBM, my TechRef
has an entry for the 256K to 640K system board.
Early PC/AT machines used those special IBM piggyback 128K 'chips'. Up to
512K on the mainboard, you could flip a jumper if you only wanted 256K.
Later PC/AT boards used 256K DRAMs, again 512K on the mainboard. The
jumper is still present, flipping it wastes half of each IC (you still
have to have all 18 chips fitted, it's a 16 bit data bus + parity on each
byte).
I _think_ the PC/XT-286 had 4 off 64K*4 and 2 off 64K * 1 DRAMs on the
mainboard for 128K RAM and then SIMM sockets for 2 256K * 9 30 pin SIMMs.
I
remember a little shop here in Santa Ana which had the first clone of
the IBM PC. It was a single board which had 640k memory, allowed
using 64k memories, instead of the 16K memory that the PC and XT
earlier models used.
DId any IBM PC/ST motherboards use 16K DRAMs. Yes, I know the standard
memory mapping PROM could be set up to use 4 rows of 4816s (64K o nthe
mainboard), but did IBM ever do that? There's no mention of it in my TechRef.
The PC used either EProms, (16K I think) and the
Roms that were
shipped with the BIOS were registered. The standard Data I/O would
Do you mean there were internal data latches in the IBM ROMs?
not read them since they were not programmable,
and needed their
output enabled to read the data.
But once someone had them in the 2716's, it was easy to get them
running in your superboard.
Surely it was trivial to use DEBUG or similar to dump the appropriate
area of memory to disk...
5:04 p.m.
the original IBM PC Bios was a Motorola 24 pin ROM. In the early
days, I used a 28 pin socket and wired to a 24 pin header to be able
to modify the bios and use a standard 28 pin EPROM for changes. There
were no latches in the ROM. It was probably cheaper for IBM to get a
masked ROM then to use EPROMs which were relatively expensive for the
quantity they were buiding. There was no EPROM equivalent for the
Motorola chip.
best regards, Steve Thatcher
Yes, as I understand it and saw, the roms could be enabled, using a
line that the data I/O didn't drive (29b variety any did not). So you got
FF out when you read them.
I can believe there were some odd enables on those ROMs, but I wasn't
aware of any internal latches. I will have a look again.
The PC used either EProms, (16K I think) and the
Roms that were
shipped with the BIOS were registered. The standard Data I/O would
Do you mean there were internal data latches in the IBM ROMs?
5:19 p.m.
If you could dismantle the PC far enough to pull the ROMs to attempt to
read them out in your programmer, then surely you could have added a
homebrew serial card or similar.
A real kludge would have been to use a couple of printer port cards
(which would give you 24 output lines) and a little external circuitry to
program an EPROM. These EPROMs were not hard to program 'by hand'.
-tony
the problem is not that obvious when pc's are everywhere.
I read the data onto a floppy on said PC. I did not own the programmer,
so transfering it via RS232 was not that useful. I could run a program and
jam it into a mini that I had (remember no nifty c or basic to process the
data on the PC to prep it for even Data I./O format)
The Data I/O's we had didn't have published or supported RS232 at
the time. This was a nasty and expensive option that was driven from mini's
or mainframes and most places had the programmer, with nothing hooked
to them. Everyone operated with a master "library" of parts stuck in
conductive foam, taped to a description of what was on the part, revisions,
p/n's when released and all that crap.
The fellows I worked with, who were the hardware enlightend made
their own programmer with an old disk controller (with 6802) providing
the intelligence and memory to support the programming. As the
system did not have the proper programming voltage, there was a
small HP lab supply fixed to the programming voltage.
It could have been used to move the data to 2732's I guess, but I didn't
have a way to get data into that system, as it again relied on reading
a source part, and programming a blank.
Jim
15 Sep
15 Sep
12:22 p.m.
A real kludge
would have been to use a couple of printer port cards
(which would give you 24 output lines) and a little external circuitry to
program an EPROM. These EPROMs were not hard to program 'by hand'.
-tony
the problem is not that obvious when pc's are everywhere.
I read the data onto a floppy on said PC. I did not own the programmer,
so transfering it via RS232 was not that useful. I could run a program and 
13 Sep
13 Sep
5:46 p.m.
On Wed, 14 Sep 2005, Tony Duell wrote:
DId any IBM PC/ST motherboards use 16K DRAMs. Yes, I
know the standard
memory mapping PROM could be set up to use 4 rows of 4816s (64K o nthe
mainboard), but did IBM ever do that? There's no mention of it in my TechRef.
The original 5150, during 1981 and part of 1982 had one row of 16K DRAMs
soldered in, and sockets for another three rows.
Later, they switched to one row of 64K DRAMs soldered in, with sockets for
another three rows. Some (all?) of those motherboards could be trivially
modified to take 2 rows of 64K plus two rows of 256K.
14 Sep
14 Sep
4:03 p.m.
Later, they switched to one row of 64K DRAMs soldered
in, with sockets for
another three rows. Some (all?) of those motherboards could be trivially
modified to take 2 rows of 64K plus two rows of 256K.
I can't rememebr if the PC 64K to 256K board has the socket for the extra
address mux chip, etc, but I think it doesn't.
All IBM PC/XT boards that I've seen can be modified to take 2 rows of
256K chips. And on all the boards I've seen, all 4 rows of RAM are
socketed, so it's easy to replace rows 0 and 1 with said 256K chips. Then
just plug in the 'S158 (or 'F158), solder the jumper and go.
-tony
13 Sep
13 Sep
7:59 p.m.
On Wed, 14 Sep 2005 00:45:56 +0100 (BST)
ard at p850ug1.demon.co.uk (Tony Duell) wrote:
The IBM PC (PC-1) had four banks of 4116 DRAM on the motherboard. The
first row was soldered in, the other three banks were optional. It was
called the 16/64K motherboard. My copy of the Technical Reference
Manual is from that generation, as it came with dad's 16/64 system. The
rest of the 256K was in the I/O channel.
Just to add more lore:
The floppy controller and floppy drive were very optional on the early
PC, and a rather pricey option. There was a cassette cable for less
wealthy users. And on any IBM machine up to the late XT era, if you
boot it up with no disk in the A drive or no floppy hardware at all
installed, it will boot into 'cassette basic'. (does anybody know if the
PC-AT had cassette basic resident in ROM?) My PC Convertable will do
so. Sadly, you can't save or load anything into 'Cassette Basic' on the
Convertable or models later than the PC as there's no cassette
interface. I wonder if anybody has ever 'back ported' the Cassette port
to an ISA bus card?? (not that it would help on the PC Convertable, of
course.
I remember a
little shop here in Santa Ana which had the first clone
of the IBM PC. It was a single board which had 640k memory, allowed
using 64k memories, instead of the 16K memory that the PC and XT
earlier models used.
DId any IBM PC/ST motherboards use 16K DRAMs. Yes, I know the standard
memory mapping PROM could be set up to use 4 rows of 4816s (64K o nthe
mainboard), but did IBM ever do that? There's no mention of it in my
TechRef.
The PC used
either EProms, (16K I think) and the Roms that were
shipped with the BIOS were registered. The standard Data I/O would
Do you mean there were internal data latches in the IBM ROMs?
not read them since they were not programmable,
and needed their
output enabled to read the data.
But once someone had them in the 2716's, it was easy to get them
running in your superboard.
Surely it was trivial to use DEBUG or similar to dump the appropriate
area of memory to disk...
First systems had a 63 watt P/S, and IBM cards if you could find
them for video. Also there was no floppy controller on the first
board.
AFAIK, no IBM PC, PC/XT, PC/XT-286, PC/AT, or PC-jr had a floppy (or
hard disk) contorller on the mainboard. None had parallel ports
either, and the PC-jr was the only one to have video and a serial port
on the mainboard.
8:22 p.m.
On 9/13/05, Scott Stevens <chenmel at earthlink.net> wrote:
The IBM PC (PC-1) had four banks of 4116 DRAM on the
motherboard...
Just to add more lore:
The floppy controller and floppy drive were very optional on the early
PC, and a rather pricey option...
Wasn't the pricing something like minimal equipment for $1695 or
$1895, but about $5K with maxed memory and two floppies?
I worked at Bruce and James Publishing when they released "WordVision"
for the PC - I still have my free copy - the back of the package says
"96K of RAM required. PC-DOS 1.0 or higher required. Floppy drive
required." They felt it was necessary to tell the potential customer
that they'd need a disk drive to use software distributed on disk.
The real "problem" with WordVision is that it uses a software timing
loop for key repeat. I ran into someone about 10 years ago selling
ancient copies of it at a HamFest, along with a patch to disable key
repeat. With that patch, it works fine on newer machines and newer
versions of DOS. I _think_ it works OK on 386s and DOS 3.3, perhaps
newer than that. Of course, without the patch, even breathing on a
key fills the screen with unwanted keystrokes. Works great on a 256K
5150, though.
-ethan
9:20 p.m.
On Tue, 13 Sep 2005, Ethan Dicks wrote:
[5150]
Wasn't the pricing something like minimal equipment for $1695 or
$1895, but about $5K with maxed memory and two floppies?
$13xx ! ($1365? $1380?) with minimum RAM, no floppies, and no adapters.
But the FDC card was about $300
the CGA card was about $300
IBM wanted something like $300 for each row of RAM! (<$100 for the same
chips "for TRS-80 or Apple")
IBM wanted something like $300 for each floppy drive (<$100 for same thing
"for TRS-80")
IBM wanted something like $600 for CGA, $300 for Mono (<$100 for composite
B&W CCTV monitor)
14 Sep
14 Sep
6:21 a.m.
On Tue, 13 Sep 2005, Ethan Dicks wrote:
I worked at Bruce and James Publishing when they
released "WordVision"
for the PC - I still have my free copy - the back of the package says
"96K of RAM required. PC-DOS 1.0 or higher required. Floppy drive
required." They felt it was necessary to tell the potential customer
that they'd need a disk drive to use software distributed on disk.
Well, of course you remember that back then disk drives were still a
somewhat expensive option, and lots of software was being distributed on
cassette back then, and it would not be obvious to the consumer whether
they were buying software on disk or cassette unless the package told
them.
--
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 ]
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27 Sep
27 Sep
12:32 p.m.
Ethan Dicks wrote:
required." They felt it was necessary to tell
the potential customer
that they'd need a disk drive to use software distributed on disk.
Or, somewhat ironically, a word processor probably wouldn't be useful if you
couldn't save your work quickly and often.
Then again, could you do useful word-processing work on a cassette-based
machine? Anyone who use Atari 8-bit, C64, etc. -- was this common? I assume
that you'd load the wordprocessor via tape, then run the machine without
powering down and save your work(s) to a blank tape... but I don't remember
that as being common; I remember disks being much more common and practical.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
2:13 p.m.
On Tue, 27 Sep 2005, Jim Leonard wrote:
Then again, could you do useful word-processing work
on a cassette-based
machine? Anyone who use Atari 8-bit, C64, etc. -- was this common? I assume
that you'd load the wordprocessor via tape, then run the machine without
powering down and save your work(s) to a blank tape... but I don't remember
that as being common; I remember disks being much more common and practical.
On TRS-80, I ran Electric Pencil and Scripsit.
Both had had some trivial mods to also support TRS-232 serial
printer interface and Exatron Stringy Floppy.
The hardware had the Elcompco mods to support Ctrl key, lower case, and
reverse video.
Overall: NOT RECOMMENDED to use tape.
--
Grumpy Ol' Fred cisin at xenosoft.com
3:07 p.m.
On Tue, 27 Sep 2005, Jim Leonard wrote:
Way back when I still was using an Imsai 8080 with Diablo daisywheel (directly driven by a
dual-parallel port interface--not a serial one) and a Beehive Superbee editing terminal, I
stored my data on a digital cassette tape drive (it allowed for speeds of up to 2400 bps
and was block-addressable). It wasn't a disk, but it did allow me to edit documents
on a page-by-page basis. You loaded a page into the Superbee, did your editing and then
hit "transmit" to send the edited data back to the CPU. I suspect I could have
done away with the CPU entirely! WYSWYG and no WordStar.
Seems to me that, although they had floppy drives, the old CPT word processors worked
exactly like this. The disks were organized by document number and page; you edited
things page by page.
It worked and was a lot faster to use than the punched-card setup I used on the
mainframe.
Cheers,
Chuck
Then again, could you do useful word-processing
work on a cassette-based
machine? Anyone who use Atari 8-bit, C64, etc. -- was this common? I
assume
that you'd load the wordprocessor via tape,
then run the machine without
powering down and save your work(s) to a blank tape... but I don't
remember
that as being common; I remember disks being much
more common and
practical.
3:28 p.m.
Then again, could you do useful word-processing work
on a cassette-based
machine? Anyone who use Atari 8-bit, C64, etc. -- was this common? I assume
Scripsit (for the TRS-80 Model 1 and 3) was certainly available on a
cassette, with load/save of your text to cassette. It worked, but it
wasn't that practical :-)
-tony
8:24 p.m.
New subject: MSX software was Re: IBM PC hacking
Then again,
could you do useful word-processing
work on a cassette-based
> machine?
14 Sep
14 Sep
4:10 p.m.
Just to add more lore:
And I'll add some more, I still use such machines...
The floppy controller and floppy drive were very
optional on the early
PC, and a rather pricey option. There was a cassette cable for less
The cassette port pinout ios the same as that for a TRS-80 (M1, M3, M4,
M100, CoCo, etc) (and for that matter a Dragon). The same cable works
with both.
wealthy users. And on any IBM machine up to the late
XT era, if you
boot it up with no disk in the A drive or no floppy hardware at all
installed, it will boot into 'cassette basic'. (does anybody know if the
PC-AT had cassette basic resident in ROM?) My PC Convertable will do
Yes it does. AFAIK all IBM PC, PC/XT, PortablePC (which is the same
mainboard as the PC/XT) and PC/AT machines have ROM BASIC. I am typing
this on a much hacked 8MHz IBM PC/AT, and it has BASIC in ROM.
so. Sadly, you can't save or load anything into
'Cassette Basic' on the
Convertable or models later than the PC as there's no cassette
interface. I wonder if anybody has ever 'back ported' the Cassette port
to an ISA bus card?? (not that it would help on the PC Convertable, of
course.
From what I remember, cassette I/O is handled via one
of the software
INTs (INT 15, maybe, I can check). The routines are only present in
the
PC BIOS, on all later machines, the routines return (maybe setting an
error flag, I forget).
But there would be no reason that a BIOS extension ROM couldn't intercept
this INT vector and perform suitable I/O, either to a cassette recorder
or to, say, a paper tape punch/reader. I have sort-of thought about
making an ISA card for the latter with the necessary ROM on it, but I
haven't got a round tuit.
-tony
15 Sep
15 Sep
12:26 p.m.
Tony Duell wrote:
IBM PC/AT case, PSU, motherboard. A 486 kludgeboard in the 286 socket. A
couple of extra EPROMs and a TTL chip to cause the former to be overlayed
over the end of the BIOS to modify the hard disk table.
An IBM memory expansion board. Started life as a 128K card, I figured out
(this is not in the Techref) that in fact it could be used with 256K*1
chips + populating the extra IC locations, to make a 1M card. Did so
A 3rd party 4M RAM card
A 3rd party card with more RAM (128K to bring the base memory up to 640K
+ another 1.5M), 2 serial ports, 1 parallel port
An IBM MDA card + monitor
A Colourgraph+ enhanced CGA card.
A IDE + floppy card. Modified wiht a bit of stripboard and a couple of
TTL chips to provide a drive-in-use LED for the iDE port. Connected to
the original IBM 1.2M drive and a Teac 1.44M drive.
-tony
I am typing
this on a much hacked 8MHz IBM PC/AT, and it has BASIC in ROM.
What *exactly* are you using here?
27 Sep
27 Sep
12:34 p.m.
Tony Duell wrote:
Yes it does. AFAIK all IBM PC, PC/XT, PortablePC
(which is the same
mainboard as the PC/XT) and PC/AT machines have ROM BASIC. I am typing
this on a much hacked 8MHz IBM PC/AT, and it has BASIC in ROM.
IIRC, a PS/2 model 25 and 30 also have BASIC in ROM. And a PCjr most certainly
does (along with a full diagnostic program and "keyboard tutorial" -- the diags
were impressive for the time).
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
11:26 a.m.
Tony Duell wrote:
Add this to this list of basic in ROM.
L40SX, an 386sx mono LCD semi-notebook.
Cheers, Wizard
Yes it does. AFAIK all IBM PC, PC/XT, PortablePC
(which is the same
mainboard as the PC/XT) and PC/AT machines have ROM BASIC. I am typing
this on a much hacked 8MHz IBM PC/AT, and it has BASIC in ROM.
IIRC, a PS/2 model 25 and 30 also have BASIC in ROM. And a PCjr most certainly
does (along with a full diagnostic program and "keyboard tutorial" -- the diags
were impressive for the time).
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
3:29 p.m.
IIRC, a PS/2 model 25 and 30 also have BASIC in ROM.
And a PCjr most certainly
does (along with a full diagnostic program and "keyboard tutorial" -- the diags
were impressive for the time).
The problem with those diagnostics (and most built-in diagnostics) is
that a fairly large part of the machine has to be operational (at least
the CPU, some memory, ROM, video) for them to be at all useful.
-tony
9:55 p.m.
Tony Duell wrote:
While it is rare that a minor error will surface in, say, the CPU (I have NEVER
seen a CPU go gradually, like "whoops, now I can't ADD or SHL" -- it's
all or
nothing), the diagnostics run in something like 1K of ROM with no memory use
other than video so they are helpful in diagnosing RAM problems. And the
sound, joystick, video, and floppy drive tests are helpful in determining if
the machine is functional on a basic level -- I always run them on any new PCjr
I come across to determine if it's worth hauling away or not :-)
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
IIRC, a PS/2
model 25 and 30 also have BASIC in ROM. And a PCjr most certainly
does (along with a full diagnostic program and "keyboard tutorial" -- the diags
were impressive for the time).
The problem with those diagnostics (and most built-in diagnostics) is
that a fairly large part of the machine has to be operational (at least
the CPU, some memory, ROM, video) for them to be at all useful. 
10:53 p.m.
other than video so they are helpful in diagnosing RAM
problems. And the
sound, joystick, video, and floppy drive tests are helpful in determining if
the machine is functional on a basic level -- I always run them on any new
PCjr I come across to determine if it's worth hauling away or not :-)
I have to admit, even though I'm not a PC fan by any means, I found the PCjr
fascinating. It didn't deserve the fate it got (though it *did* deserve a
better price point than it was saddled with).
--
---------------------------------- personal: http://www.armory.com/~spectre/ --
Cameron Kaiser, Floodgap Systems Ltd * So. Calif., USA * ckaiser at floodgap.com
-- Never underestimate the power of stupid people in large groups. ------------
28 Sep
28 Sep
3:34 p.m.
Cameron Kaiser wrote:
I have several, as I've always found them fascinating:
- They had diagnostics, BASIC, a "game" and other stuff in ROM
- They introduced 16-color graphics and 3-voice sound to the world of PC games,
however it was Tandy's CLONE of those graphics and sound that became popular
and advanced the industry
- To reduce costs, the case of the PCjr is not metal but plastic coated in
metal -- IBM patented a new process to do this (I'm not sure if they sprayed it
on or if it was dipped)
- The system is so small and light, it is more portable than the original
Compaq deskpro :-)
- built-in modem (albeit 300 baud)
In short, a radical departure from the model 5150. If it cost half of what it
debuted at, and came with a floppy drive standard, it easily would have taken
over. A fascinating little machine.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
other than
video so they are helpful in diagnosing RAM problems. And the
sound, joystick, video, and floppy drive tests are helpful in determining if
the machine is functional on a basic level -- I always run them on any new
PCjr I come across to determine if it's worth hauling away or not :-)
I have to admit, even though I'm not a PC fan by any means, I found the PCjr
fascinating. It didn't deserve the fate it got (though it *did* deserve a
better price point than it was saddled with).
4:11 p.m.
On Wed, 28 Sep 2005 17:34:46 -0500
Jim Leonard <trixter at oldskool.org> wrote:
PC games,
Cameron Kaiser wrote:
>>other than video so they are helpful in diagnosing RAM problems.
And the
>>sound, joystick, video, and floppy drive tests
are helpful in
determining if
>>the machine is functional on a basic level --
I always run them on
any new
>>PCjr I come across to determine if it's
worth hauling away or not
:-)
>
> I have to admit, even though I'm not a PC fan by any means, I found
the
PCjr
> fascinating. It didn't deserve the fate it
got (though it *did*
deserve a
better price
point than it was saddled with).
I have several, as I've always found them fascinating:
- They had diagnostics, BASIC, a "game" and other stuff in ROM
- They introduced 16-color graphics and 3-voice sound to the world of however it was Tandy's CLONE of those graphics and
sound that became
popular
and advanced the industry
- To reduce costs, the case of the PCjr is not metal but plastic
coated in
metal -- IBM patented a new process to do this
(I'm not sure if they
sprayed it
on or if it was dipped)
The PCjr also lacked a DMA controller. So all diskette data has to pass
through the CPU's accumulator, which makes it significantly slower than
a PC-XT. I remember running a Norton SI on my Junior. It had a SI of
.7 which was actually 'inflated' since that rating didn't benchmark the
abcence of DMA.
I used to enjoy playing '3-Demon' on the Junior. 3-Demon was a
'wireframe' 3-D version of Pacman. If you turned down a row that was
the full legnth of the maze, the machine markedly slowed down as it
struggled to render the deeper wireframe graphics. 3-Demon was a truly
advanced graphic application to run on a first-generation PC.
5:23 p.m.
Scott Stevens wrote:
3-Demon was a truly
advanced graphic application to run on a first-generation PC.
You haven't tried Flight Simulator on a PCjr, evidently :-) THAT was advanced.
(And aware -- if you had version 2.0, it could detect if you had extra memory
and offered to move the program into that extra RAM so it could run faster)
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
6:40 p.m.
I have to
admit, even though I'm not a PC fan by any means, I found the PCjr
fascinating. It didn't deserve the fate it got (though it *did* deserve a
better price point than it was saddled with).
I have several, as I've always found them fascinating:
- They had diagnostics, BASIC, a "game" and other stuff in ROM
7:05 p.m.
On 9/28/2005 at 9:40 PM William Donzelli wrote:
Okay, I don't get it. What's so special about a plastic box with a wimpy power
supply (what was it, 32 watts?) that can't even do DMA, for the love of Mike? A
friend who should've known better bought one and upgraded it, bit by bit, to include a
hard disk and, I believe, an external ISA card cage. He spent more on getting that poor
thing to some sort of usefulness than he would have had he purchased a regular PC/XT (much
less a clone). Even so, he kept running into the "Sorry, this doesn't work on a
PC Jr." situation.
I think it's pretty clear that IBM intended the PC Jr. as a teaser to eventually get
you to upgrade to a standard XT. Did IBM dealers offer trade-in deals?
Cheers,
Chuck
> I have to
admit, even though I'm not a PC fan by any means, I found
the PCjr
> fascinating. It didn't deserve the fate
it got (though it *did*
deserve a
> > better price point than it was saddled with).
>
> I have several, as I've always found them fascinating:
29 Sep
29 Sep
7:44 a.m.
the eccentricity of some of these early machines is
what makes them so interesting. At least a Peanut
could run some PC software, alot actually! Not so on
the Tandy 2000...or TI PC...or NEC APC/III...or Victor
9000...or DEC Rainbow...
Ok ok, some of them had "compatibility options". My
NEC APC III has that. Haven't played with it much. I
reckon it'll be just shy of dissappointing.
I reckon most people don't collect this stuph becuase
they can't find anything better to work on LOL LOL.
--- Chuck Guzis <cclist at sydex.com> wrote:
On 9/28/2005 at 9:40 PM William Donzelli wrote:
__________________________________
Yahoo! Mail - PC Magazine Editors' Choice 2005
http://mail.yahoo.com
> > I have to admit, even though I'm not
a PC fan
by any means, I found
the PCjr
> > fascinating. It didn't deserve the fate it got
(though it *did*
deserve a
> > better price point than it was saddled with).
>
> I have several, as I've always found them
fascinating:
Okay, I don't get it. What's so special about a
plastic box with a wimpy power supply (what was it,
32 watts?) that can't even do DMA, for the love of
Mike? A friend who should've known better bought
one and upgraded it, bit by bit, to include a hard
disk and, I believe, an external ISA card cage. He
spent more on getting that poor thing to some sort
of usefulness than he would have had he purchased a
regular PC/XT (much less a clone). Even so, he kept
running into the "Sorry, this doesn't work on a PC
Jr." situation.
I think it's pretty clear that IBM intended the PC
Jr. as a teaser to eventually get you to upgrade to
a standard XT. Did IBM dealers offer trade-in
deals?
Cheers,
Chuck
30 Sep
30 Sep
7:53 p.m.
Chuck Guzis wrote:
Okay, I don't get it. What's so special about
a plastic box with a wimpy power supply (what was it, 32 watts?) that can't even do
DMA, for the love of Mike? A friend who should've known better bought one and
upgraded it, bit by bit, to include a hard disk and, I believe, an external ISA card cage.
He spent more on getting that poor thing to some sort of usefulness than he would have
had he purchased a regular PC/XT (much less a clone). Even so, he kept running into the
"Sorry, this doesn't work on a PC Jr." situation.
What was special about it wasn't necessarily what it was, but what it was
trying to be. Very interesting design choices and direction for IBM.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
1 Oct
1 Oct
10:22 a.m.
--- Jim Leonard <trixter at oldskool.org> wrote:
What was special about it wasn't necessarily what
it
was, but what it was
trying to be. Very interesting design choices and
direction for IBM.
--
Jim Leonard (trixter at oldskool.org)
Didn't the Peanut employ some sort of video gate
array that made the video memory, actually existing
low in ram, appear to be @ b800:0000? I read something
to that effect in "the IBM Personal Computer from the
Inside Out".
A gentleman I'm in contact with attempted to develop
a mod for the Tandy 2000 that enabled PC compatiblity.
I can understand some degree of what's being said
(though not necessarily how to put it all together),
but maybe my placing it here will provoke discussion.
Sounds kind of sort of like what was going on with the
Jr.
And actually, I thought a memory parity error always
generated a NMI, or at least most PC's were designed
to.
I was working on a mod, never completed, for the T2K
that would make it
after the O/S was loaded, 100% PC-compatible.
Required 1 hardware chip,
and customized software. Whereupon any DOS
application would run on the T2K,
even stuff doing serial-port manipulation, direct
video-memory writes, DMA,
etc.
The one-chip mod was a PAL that monitored the address
lines from the
CPU,
when It saw an I/O instruction in 'low'
address->space, it generated an
NMI (not used at all by the T2K), then the software
service routine
for NMI unwound the stack to find the offending I/O
instruction, and
re-mapped the "PC" functionality to the T2K
hardware. Coupled with a
timer-tick 'refresh' routine that copied data >from
"PC video
memory" to
the T2K video memory (remapping attributes, etc. as
required.)
The chip actually had 2 modes of operation -- NMI
active, as described
above, and 'NMI inactive', where it pretty much did
nothing -- except
listen for the 'magic words' that made it go active,
that is. :) This
enable/disable mode switching was necessary, to
allow "T2K DOS"
internals
(and/or the 'sofware service routine) to access the
T2K hardware
directly.
__________________________________
Yahoo! Mail - PC Magazine Editors' Choice 2005
http://mail.yahoo.com
28 Sep
28 Sep
12:09 p.m.
On Tue, 27 Sep 2005, Jim Leonard wrote:
While it is rare that a minor error will surface in,
say, the CPU (I have NEVER
seen a CPU go gradually, like "whoops, now I can't ADD or SHL" -- it's
all or
nothing), the diagnostics run in something like 1K of ROM with no memory use
other than video so they are helpful in diagnosing RAM problems. And the
sound, joystick, video, and floppy drive tests are helpful in determining if
the machine is functional on a basic level -- I always run them on any new PCjr
I come across to determine if it's worth hauling away or not :-)
Hey Jim.
How do you access the diagnostics?
--
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 ]
3:26 p.m.
Vintage Computer Festival wrote:
How do you access the diagnostics?
CTRL-ALT-INS, which I find strangely appropriate :-)
The "BASIC Adventure", however, was stupid and misguided. Boot with no disk in
the drive and no hard drive, and you'll go into BASIC. Hit ESC as the very
first key and you'll go into this... game-thing-whatever it is.
http://www.eeggs.com/items/40624.html has documentation.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
5:28 p.m.
On Wed, 28 Sep 2005, Jim Leonard wrote:
The "BASIC Adventure", however, was stupid
and misguided. Boot with no disk in
the drive and no hard drive, and you'll go into BASIC. Hit ESC as the very
first key and you'll go into this... game-thing-whatever it is.
http://www.eeggs.com/items/40624.html has documentation.
Cool! I love hardware easter eggs. There's a few I know of in the Mac
and in Apple ]['s, including the //c and the //gs.
Here's the Apple //c one:
Apple //c (Original)
Entering the following program from BASIC will produce the names of three
people on the Apple //c programming team:
10 IN#5
20 INPUT A$
30 PRINT A$
This is an excerpt from a file I put out years ago:
http://siconic.com/files/dsgskeehm
Please excuse the lame rhetoric...I was way uptight back then.
--
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 ]
3:59 p.m.
The problem
with those diagnostics (and most built-in diagnostics) is
that a fairly large part of the machine has to be operational (at least
the CPU, some memory, ROM, video) for them to be at all useful.
While it is rare that a minor error will surface in, say, the CPU (I have NEVER
seen a CPU go gradually, like "whoops, now I can't ADD or SHL" -- it's
all or nothing), the diagnostics run in something like 1K of
ROM with no memory use
other than video so they are helpful in diagnosing RAM problems. And the
IIRC, there is no separate video RAM on the PCjr, the video circuit just
takes some of the main RAM. And while you can have random bit failures in
RAM, I've found that either complete chips failing or address inputs
failing (so that locations appear to repeat) is much more common.
sound, joystick, video, and floppy drive tests are
helpful in determining if
the machine is functional on a basic level -- I always run them on any new PCjr
I come across to determine if it's worth hauling away or not :-)
Over here, PCjr machines are sufficiently rare that just about any is
worth grabbing.
Apart from a defective gate array chip, I think just about any problem is
repairable.
-tony
3:57 a.m.
Jim Leonard wrote:
Tony Duell wrote:
AFAIK, all IBM PS/2's have BASIC in ROM. My Model 50, 80, 90 and 95 all
do. Maybe some of the executive series machines don't, but all the ones
I've seen do.
Peace... Sridhar
Yes it does. AFAIK all IBM PC, PC/XT, PortablePC
(which is the same
mainboard as the PC/XT) and PC/AT machines have ROM BASIC. I am typing
this on a much hacked 8MHz IBM PC/AT, and it has BASIC in ROM.
IIRC, a PS/2 model 25 and 30 also have BASIC in ROM. And a PCjr most
certainly does (along with a full diagnostic program and "keyboard
tutorial" -- the diags were impressive for the time).
29 Sep
29 Sep
8:03 a.m.
I am trying to find a reason to keep my PCjr, so it
comes down to this -
were there any mainframe communications developed for
the thing?
Hey, even the 5100 could talk to an S/3.
I'm sure I'll wind up with egg on my face here, but I
can't imagine the setting in which a Peanut is
communicating with a mainframe. Maybe a former CEO of
Planter's had one on his desk? I know, I shouldn't
quit my day job.
A friend is looking for some weird networking
option/cart for his Jr. Anybody know of one?
__________________________________
Yahoo! Mail - PC Magazine Editors' Choice 2005
http://mail.yahoo.com
5:59 p.m.
I'm sure I'll wind up with egg on my face
here, but I
can't imagine the setting in which a Peanut is
communicating with a mainframe. Maybe a former CEO of
Planter's had one on his desk? I know, I shouldn't
quit my day job.
Ulikely, yes, but I a desperate for a reason.
William Donzelli
aw288 at osfn.org
13 Sep
13 Sep
5:41 p.m.
On Tue, 13 Sep 2005, jim stephens wrote:
It was called "Superboard" and was no
relation to Supermicro, which
came much later. It had a bios that usually worked, but also had,
conveniently, a spot for up to 6 eprom chips, so you could put in a
PC bios if you could get a copy.
The "Superboard"s that I got were bare boards, with NO parts.
I filled them with Augat sockets. By the time that I was done,
my soldering had improved substantially.
The PC used either EProms, (16K I think) and the Roms
that were
shipped with the BIOS were registered. The standard Data I/O would
not read them since they were not programmable, and needed their
output enabled to read the data.
I just went into DEBUG, copied the 5150 ROMs to an available segment,
and wrote them to files. For reasons that I never found out, The
IBM ROMs, and copies thereof, could not handle DRIVPARM (present in
DOS 3.20 and above. But most aftermarket ROMs could.
First systems had a 63 watt P/S, and IBM cards if you
could find
them for video. Also there was no floppy controller on the first
board.
But there were also bare boards available for FDC, CGA, etc.
Maybe others of you can recall expansion card makers,
of such
things as serial, parallel, memory, floppy, then hard drive, etc.
The first aftermarket memory board was from Boulder Creek Systems.
It even did ECC!
I have some Tecmar "modular multifunction" boards to sell off the next
time that I can make it to VCF. Unfortunately, I am stuck with teaching
Saturdays this semester :-(
--
Grumpy Ol' Fred cisin at xenosoft.com
14 Sep
14 Sep
4:19 p.m.
--- jim stephens <jwstephens at msm.umr.edu> wrote:
This auction is for a "zukerboard" 576K mem
expansion. 6801436037.
I remember the hype for zucker that they were going
to wreck the
market.
IIRC, that board was one of many multi multi-function
cards. Everything including the kitchen sink. The
original PC had 5 slots, as did some clones (Tandy
1000 comes to mind). So it was advantageous to have
every bloody thing you needed on one card if possible.
Again, iirc, the zukerboard or whatever was sort of
cheapo. Don't quote me.
I know of at least Zucker, Tecmar (marty tech, I
don't remember marty's
last name, but he was some sort of PHD ohio type, I
think).
There were a bunch, even into the (late) EGA days
(you could get 800 x 600 and maybe better with some
cards, as long as you had a multisync monitor). Don't
forget the overseas types which didn't carry any
particular vendor's name.
I remember a little shop here in Santa Ana which had
the first clone of
the IBM PC. It was a single board which had 640k
memory, allowed
using 64k memories, instead of the 16K memory that
the PC and XT
earlier models used.
Um, care to dig up some research on that? The FIRST
clone??? Get back to us, ay? *lol*
But once someone had them in the 2716's, it was
easy
to get them
running in your superboard.
Dvorak wrote in his column that there was piracy of
this sort on a grand scale...across the border. You
figure out which border I'm talking about. tee hee
Maybe others of you can recall expansion card
makers, of such
things as serial, parallel, memory, floppy, then
hard drive, etc.
I find the 400 line graphic cards the most
interesting. Sigma 400, STB, Tecmar, Taxan, and others
made them. Then there's IBM's PGA card. I have a
similar card made by Vermont Microsystems. Takes up 2
slots, and has an onboard 80186. Works the last time I
tried it, but probably impossible to find drivers or
docs for.
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27 Sep
27 Sep
12:42 p.m.
Chris M wrote:
I find the 400 line graphic cards the most
interesting. Sigma 400, STB, Tecmar, Taxan, and others
My AT&T PC 6300 (Olivetti M24 clone) had this but it wasn't as exotic as the
hardware mentioned above: The stock Motorola 6845 character generator (MC6845)
was used, but it just pointed to an 8x16 character table so you got nicer
characters in 400-line mode. 200-line modes were just scanline-doubled. Pro?
a true 640x400-line high-res mode. Con? Games that used text character
"graphics" (that took the stock IBM 8x8 font into account when they were
created) didn't look right.
Oh, another favorite feature: The card had a signal line that could activate
the degaussing circuit on the bundled AT&T monitor. I almost fell out of my
chair when I ran diagnostic software that printed something like
"Degaussing..." and then was quickly followed by a loud noise and the familiar
"twisty pix" distortion of a monitor in its degaussing cycle... scared the
crap out of me.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
3:32 p.m.
Oh, another favorite feature: The card had a signal
line that could activate
the degaussing circuit on the bundled AT&T monitor. I almost fell out of my
chair when I ran diagnostic software that printed something like
"Degaussing..." and then was quickly followed by a loud noise and the familiar
"twisty pix" distortion of a monitor in its degaussing cycle... scared the
crap out of me.
I beleive the HP9845C (colour monitor) had a DEGAUSS command in the BASIC
that would energise the degausing coil. And a CONVERGE command that would
display the appropriate patterns for doing convergeance adjustments. Alas
I only have a 9845B (with the enhanced mono monitor) so I cna't try them out.
-tony
6984
days inactive
7001
days old
44 comments
15 participants
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-
ard＠p850ug1.demon.co.uk -
aw288＠osfn.org -
cclist＠sydex.com -
chenmel＠earthlink.net -
chrism3667＠yahoo.com -
cisin＠xenosoft.com -
ethan.dicks＠gmail.com -
gordon＠gjcp.net -
jpero＠sympatico.ca -
jwstephens＠msm.umr.edu -
melamy＠earthlink.net -
ploopster＠gmail.com -
spectre＠floodgap.com -
trixter＠oldskool.org -
vcf＠siconic.com