Tony Duell originally asked this but the group may be interested. The MMD1
8080 trainer was based on a design by Jonathan Titus and Company (Tychon
Inc.) and was apparently described in a series of articles in the May-July
1976 Radio Electronics, however it is also described in "The 8080a Bugbook",
a Howard Sams book (ISBN 0-672-21447-4), 1977.
Tony: the two ROM sockets are for 1702 ROMS. The very simple but efficient
monitor, called KEX for "Keyboard Executive", easily fits in the 256 byte
space of one of these, leaving ROM socket 1 for "expansion".
I don't have access to the original articles on this unit but it was easy
enough to reverse engineer the assembly listing of KEX, below. I'd give
y'all instructions on using the monitor but that would take the fun out of
reading the source listing! i've also stuck the HEX file at the end of the
listing. have fun!
- Glenn
* KEX.ASM
*
* Keypad EXecutive
*
* This is a reverse engineered assembly listing
* of the 8080 trainer ROM. For more information see
* Radio Electronics May-July 1976 issues, also Chapter 2
* of "The 8080 Bugbook"
*
* Glenn Roberts 2/13/97
*
RST1 SET 003010A
RST2 SET 003020A
RST3 SET 003030A
RST4 SET 003040A
RST5 SET 003050A
RST6 SET 003060A
STACK SET 004000A
USERFWA SET 003000A
*
* Keypad equates
*
H.KEY EQU 10Q
L.KEY EQU 11Q
G.KEY EQU 12Q
S.KEY EQU 13Q
A.KEY EQU 15Q
B.KEY EQU 16Q
C.KEY EQU 17Q
ORG 0
JMP START
DS 5
JMP RST1
DS 5
JMP RST2
DS 5
JMP RST3
DS 5
JMP RST4
DS 5
JMP RST5
DS 5
JMP RST6
DS 5
*
* Cold boot entry, load stack and memory pointer
*
START LXI SP,STACK
LXI H,USERFWA
MAIN MOV C,M ; C is value to be displayed
MOV A,H ; Output High byte
OUT 1 ; of memory counter to left LEDs
MOV A,L ; and low byte of memory counter
OUT 0 ; to center LEDs
*
* Loop to process keypad input
*
KPLOOP MOV A,C ; output the value of C to
OUT 2 ; the rightmost LEDs
L110 CALL RDKEY ; Read key from keypad
CPI 8 ; Is it numeric octal? (0-7)
JNC L134 ; no, test for others
MOV B,A ; Temp save in B
MOV A,C ; Get the current working byte
RAL ; and move it left 3 bits
RAL
RAL
ANI 11111000B ; then clear low 3 bits
ORA B ; and insert temp value (B) there
MOV C,A ; then move back to C
JMP KPLOOP
L134 CPI L.KEY ; Was key "L"?
JNZ L345 ; no
MOV L,C ; yes, move working byte to L
JMP MAIN ; and go to top
CPI H.KEY ; Was key "H"?
JNZ L156 ; no
MOV H,C ; yes, move working byte to H
JMP MAIN ; and go to top
L156 CPI S.KEY ; Was key "S" (step)?
JNZ L170 ; no
MOV M,C ; yes, move working byte to memory
INX H ; increment memory pointer
JMP MAIN ; and go to top
L170 CPI G.KEY ; Was key "G" (go)?
JNZ L110 ; no
PCHL ; yes - load Program Counter from HL
DS 65 ; filler
*
* Delay (debounce)
*
* This routine delays for a bit over 10ms.
* Note cycle time is 1.5 microseconds
* Total delay: 62 + (294 * 24) = 7,118 cycles
* 7,118 * 1.5 = 10.677 ms.
*
DELAY PUSH PSW
PUSH D
LXI D,294 ; Number of times to loop
DLY1 DCX D ; Decrement DE
MOV A,D ; and test for DE = 0
ORA E
JNZ DLY1 ; if not, keep looping
POP D
POP PSW
RET
*
* Read a key from the keypad (with debouncing)
*
RDKEY IN 0 ; Read the keypad port
ORA A ; set flags
JM RDKEY ; no key depressed - loop
CALL DELAY ; have key, debounce
RDK1 IN 0 ; Re-read the key
ORA A ; set flags
JP RDK1 ; key still depressed - loop
CALL DELAY ; key released, wait
IN 0 ; Read once more
ORA A ; set flags
JP RDK1
L345 ANI 00001111B ; Only lower nibble of interest
PUSH H
MVI H,0 ; Set HL to point to table
ADI #TABLE
MOV L,A
MOV A,M
POP H
RET
*
* Lookup table for keypad
*
TABLE DB 0,1,2,3,4,5,6,7
DB S.KEY
DB 0
DB C.KEY
DB G.KEY
DB H.KEY
DB L.KEY
DB A.KEY
DB B.KEY
END START
:10000000C33800BB3A32D63AC30803318022CD5EF2
:10001000C31003210842CD46C3180323CDEC3D1184
:10002000C320030842CD7041C32803AF328C3A325B
:10003000C33003153B2108423100042100034E7CEC
:10004000D3017DD30079D302CDCD00FE08D25C0070
:100050004779171717E6F8B04FC34500FE09C2E508
:100060000069C33E00FE08C26E0061C33E00FE0B85
:10007000C278007123C33E00FE0AC24800E93B116A
:100080000142017B3BFF2B3A7B3BE601C178D1E18A
:10009000CA263DFE3DC2103DCD7F3DDAE23B21DF69
:1000A0003ACD8734FE2CCC213E21DF3A11FB4101B1
:1000B0007B3BFF2B3A7B3BE601CAC03C21D53AF59E
:1000C000D51126011B7AB3C2C400D1F1C9DB00B738
:1000D000FACD00CDBF00DB00B7F2D600CDBF00DB0C
:1000E00000B7F2D600E60FE52600C6F06F7EE1C944
:1000F00000010203040506070B000F0A08090D0E94
:00003801C7
>
>I seem to recall reading somewhere (BYTE ~1985 ?) that Soviet made CPUs
>(6502 clones?) were so poorly maid that they individually came with a
>list of which instuctions worked and which didn't. Also seem to
recall
>an article on the soviet Apple ][ clone of the time (CPU on a large
>daughterboard, pirated ROM, cost approx US $20,000)
>
>-Matt Pritchard
>Graphics Engine and Optimization Specialist
>MS Age of Empires & Age of Empires ][
All right, I have taken this for a while, but no more. This ignorance
about Soviet technology and abilities is ridiculous. I think you
people have kept your anti-communist opinions along with you IBM
704s.
Although the USSR certainly had ridiculous administration, and its
technology was not very modern, there were many advances by the
soviet union, and it now has just as much technology as the US.
Lastly, the US scored below Russia in third grade math tests. Also,
a LOT of modern programmers are Russian. Most Russian immigrants
I know deal with computers.
When I was in first grade (1990), we were first led into our school's
new computer room. It had a classroom of terminals (in plywood cases),
and a punched card machine. My young mind could not discern any other
details.
I don't mean to be ridiculous, but please be a bit more careful,
people!
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
>
>> All right, I have taken this for a while, but no more. This ignorance
>> about Soviet technology and abilities is ridiculous. I think you
>> people have kept your anti-communist opinions along with you IBM
>> 704s.
>>
>> Although the USSR certainly had ridiculous administration, and its
>> technology was not very modern, there were many advances by the
>> soviet union, and it now has just as much technology as the US.
>>
>
>The soviets always had comparable technology, but were limited by
>inefficient manufacturing and logistics. Those only exposed to western
>design philosophy tend to belittle soviet engineers because of the
>seemingly crude appearance of their equipment, but they had to meet
>vastly different product requirements. Their export market was the
>underdeveloped third world, no infrastructure at all. When your target
>market is some place like Mongolia, Eritrea or South Yemen you have an
>entirely different set of design parameters. There is no Radio Shack
>down the corner, no parts store in town, no UPS delivery service. Even
Why Radio Shack when you have BFI? I can just imagine a fried US
made cell phone flying into a third-world bonfire...that sure would
stink. Another reason why Russian products were build to last was,
very simply, because if you trash your phone, you'd have to get on
a two-month waiting list to get another one.
> Jack Peacock
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Found on Usenet. If you want to do some trading, contact him directly.
-=-=- <snip> -=-=-
From: psthomas(a)nyx.nyx.net (Patrick Thomas)
Newsgroups: comp.sys.dec.micro
Subject: Anyone trade sun->vax stuff?
Date: 15 Apr 1998 04:03:42 GMT
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Hi again, all...
Well, after some four years of absence, my curiousity has again
been piqued. After having to divest myself of my collection of VAX
hardware in my move to the west coast, I find myself interested to
find a microvax or vaxstation again. Even (gasp) a VAXstation 2000, if
nothing else. I have a bunch of Sun 3/60s, and even a an IPC, and
possibly an HP 9000/400 that I'd be willing to part with, if anyone
might be interested. Or I can always go with cash, for those less-
enterprising types. :)
I live in Portland, now, and will pick up anything in the portland/seattle
areas. I also remember how cheap VAXstation 2000s were four years ago,
and I would suspect they aren't old enough to be collectible quite yet. :)
I'd be more interested in something like a vs3x00 or some such.
-- Patrick
-=-=-=-=-=-=-=-=-
Bruce Lane, SysOp,
The Dragon's Cave BBS (Fido 1:343/272)
kyrrin {at} j<p>s d[o]t n=e=t
"...No matter how hard we may wish otherwise, our science can only describe
an object, event, or living creature, in our own human terms. It cannot possibly
define any of them!..."
<> a problem. The Northstar Horizon was good, VECTOR MZ, COMPUPRO and the
<> was an oufit that made mostly boxes all well cooled.
<
<Integrand?
One I'd kill for even now. They designed for cooling and still had an
attractive box.
Allison
> > Some of the better boxes had put some thought to air flow
> and this was not
> > a problem. The Northstar Horizon was good, VECTOR MZ,
> COMPUPRO and there
> > was an oufit that made mostly boxes all well cooled.
>
> Integrand?
The Integrand was one of the best. I still have one of their big S-100
boxes, fans everywhere, monster transformer in the power supply, but
somewhat dificult to use all the DB cutouts on the back.
Jack Peacock
<signal lines. Every board required it's own regulation, which
<could take 20% or more of the board space, as well as being a
<nightmare to keep cool. If you see early pictures of loaded
<IMSAIs, the cover was always off. This was a necessity, the
<heat was too much with the cover on. I had to use a 16" fan to
<keep mine running with 64KB of 2102 based static RAM (not 21L02s
<BTW, they cost more than the fan did).
Some of the batter boxes had put some thought to air flw and this was not
a problem. The Northstar Horizon was good, VECTOR MZ, COMPUPRO and there
was an oufit that made mostly boxes all well cooled.
In the mid to late 70s it was either boxed systems like TRS-80, Apple
or designer systems like S100 or SS50. SS50 was 6800 based 50 pin bus
and tended to be a very different thinking.
Allison
On Apr 14, 23:22, Tony Duell wrote:
> > On Apr 14, 0:40, David Williams wrote:
> > > You can see pictures of it on my web site on the AT&T 6300 page
>
> Having a text-only machine here, I can't see the pictures, alas...
There's a lot of brown/grey corrosion on the top surface near the terminals,
and not a lot else visible on the PSU itself, though it looks like there's some
on the base of the computer case around the PSU.
> > wipe off any excess WD40, though.
>
> I _hate_ WD40... It's far too easy to misuse and causes too many
> problems.
I prefer WD40 to machine oil for electricial connections, but I have to agree
with Tony that it's very easy to misuse. It should be supplied in
micro-syringes, not spray cans, IMNSHO. Or only available on prescription,
perhaps. That's why I said to be sure to wipe off the excess.
And WD40 should be kept away from moving metal parts. It's sometimes useful as
a plastic anti-squeak lubricant, but definitely not for metals. I use
CLP-BreakFree for that :-)
> and light machine oil. Start with (UK) 600 grit, end with 1000 grit, at
> least. I'd clean the screw terminals with dry 600 grit paper and then
> contact cleaner.
I've seen contact cleaner seriously misused too. Some types leave "a light
film" behind -- if you use a little, once. I once had to fix a BBC Micro with
faulty ROM sockets; the owner had repeatedly fed it contact cleaner until it
was swimming in the stuff. ISTR cleaning most of it off with 1,1,1-TCE and
then washing the board in Teepol (industrial grade/laboratory detergent) before
it could be attacked with a soldering iron.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
OK... I was talking to a Ukranian programmer, who told me that in 1968 the
PC was invented, not far from where he worked in Ukrane. Now, that's 4
years before the microprocessor, but is it possible?
And this guy might be dilusional, he's VERY communist, but then again,
at base, so am I, but with a democratic twist. Anyway, what's the story
behind this?
Thanks,
Tim D. Hotze
Hi tony,
you know where to get the amd assembler for this stuff ?
cheers,
emanuel
----------
> From: Tony Duell <ard(a)p850ug1.demon.co.uk>
> To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
> Subject: Re: neat find
> Date: Tuesday, April 14, 1998 3:14 PM
>
> >
> > today at goodwill I found a Advance Micro Device AM2900 Evaluation &
> > Learning Kit in the it's box (very nice design on it) with one
worksheet.
> > the unit was only $5.
>
> The comment 'you lucky beggar' springs to mind !.
>
>
> The AMD 2900 series of chips were essentially a build-it-yourself CPU.
> The main ones were :
>
> The 2901 - a 4 bit ALU + registers. You could cascade these to give you
as
> many bits as you wanted (in multiples of 4). There was also a fast carry
> generator, equivalent to the 74182. Was that the 2902?
>
> The 2903 was an enchanced 2901 AFAIK. I never used it.
>
> Then there were the 2909 and 2911 4-bit microcode sequencers. You
> cascaded those as well to access whatever size control store you wanted.
> Add a bit of jump logic, and write the microcode to control your CPU.
>
> For simpler designes there was the 2910 12 bit sequencer which couldn't
> easily be extended (*). That would seqeunce a 4K control store, and had
> some of the jump control logic built-in.
>
> I've done a bit with these chips, and was reading the data books earlier
> today, actually. Great pity they're no longer made...
>
> (*) PERQ systems used a 2910 as the sequencer on the 4K PERQ CPU board.
> The 16K CPU board also used a 2910 with a '2 bit kludge' to provide the
> extra address lines. The pun on '2 bit' is intentional, and will be
> understood by anybody who's ever written PERQ microcode...
>
> >
> >
>
> -tony
>> Such innovation, but it ended up in vain efforts just cloning
>> IBM mainframes
>> and the like. Sound like a company you know? (Minus the vain).
>
>Several companies: RCA Spectra, XDS Sigma, Amdahl, Fujitsu, Hitachi ...
> Jack "I love MS, MS loves me" Peacock
You're right. I actually have nothing against MS, just it's current
product line and a few of it's business practices. A good company shouldn't
need to um... err.... ahh... lobby (that's it!) anyone.
Tim "Who Care's About MS, except when you need to" Hotze
> Such innovation, but it ended up in vain efforts just cloning
> IBM mainframes
> and the like. Sound like a company you know? (Minus the vain).
Several companies: RCA Spectra, XDS Sigma, Amdahl, Fujitsu, Hitachi ...
Jack "I love MS, MS loves me" Peacock
>Yes it is possible, if you play with the meaning of "PC". If you define
>it to mean a small computer used by a single person, then a low end mini
>computer becomes a PC. In which case we have to go all the way back to
Yes, but it would have to fit in a space that people can have.. say... at
home.
>machines like the Bendix G-15 (late 50s ?). The USSR did not have
>microprocessors before the US.
And the US was not developing an atomic bomb during WWII.
>That's easy to prove, because soviet
>micros all used US designed instruction sets. How could they produce an
>8080 compatible IC before it was released by Intel?
A better question: How could Intel make a 8080 compatible machine before it
was produced by the Soviets? ;-)
Honestly, I think that Soviet computers are, on the whole, a sad story.
Such innovation, but it ended up in vain efforts just cloning IBM mainframes
and the like. Sound like a company you know? (Minus the vain).
Tim D. Hotze
> OK... I was talking to a Ukranian programmer, who told me
> that in 1968 the
> PC was invented, not far from where he worked in Ukrane.
> Now, that's 4
> years before the microprocessor, but is it possible?
Yes it is possible, if you play with the meaning of "PC". If you define
it to mean a small computer used by a single person, then a low end mini
computer becomes a PC. In which case we have to go all the way back to
machines like the Bendix G-15 (late 50s ?). The USSR did not have
microprocessors before the US. That's easy to prove, because soviet
micros all used US designed instruction sets. How could they produce an
8080 compatible IC before it was released by Intel?
Jack Peacock
>It's easy to blame novice users and get rich quick spammers, but I can't
>agree with you. I look on the 'Net as evolution in action. Right now
>we have the feeding frenzy of spammers drowning us in unwanted email.
>The easy, and wrong, solution is to force them to stop. The right way
>is to make it uneconomical for them to send spam. How? I don't really
>know, I just ignore it, sort of like background static noise on a
>shortwave radio.
In general, it is ignored. I know someone, who recently got online. They
own a small company, and were offered 15,000 eMail addresses at .01 per
person. That sounded like such a great deal! So, they sent the e-mail, and
got 200 eMails that bounced, then in 3 months, had recieved 6 orderes for $5
and over 500 eMails about the bad business practices of spamming. They knew
no better, but still...
>But consider, what kind of response rate do spammers get? Now junk
>snail mailers have to actually pay per piece, although at a reduced
>rate. They have to make the junk mail attractive to readers so they can
>get a high enough response rate to justify the mailing. Maybe we need
>the same mechanism for mass commercial postings. In other words, the
>ISP specifies in the terms of service that mass commercial mailings (aka
>spam) are charged at the same mailing rates as the local post office,
>something around 20 cents per item. Now you have a legal means to get
>back if the ISP catches a spammer, because they are liable for the
>contracted costs.
Spam should be illegal. The commercialization of the Internet's what we
needed for a long time: a worldwide information resource. Allowing people
to profit by it (by ads, etc.) gives you more information available, and a
wider user base. Even sci-fi writers didn't envision a global information
resource like ours for another ten to twenty years. Let's face it: Until we
go past the money-stage, for many things to become popular, they seemingly
MUST be commercial.
<> S-100s started out with an Intel 8080, then Zilog Z80. That was
<> pretty much the end of the 8-bit version, although there were
<
<Hmmm...this is sort of like the Creationist version of where S-100 came
<from. Actually, a guy named Ed Roberts at a company called MITS that
<built a computer called the Altair 8800 invented the S-100 bus.
It's the of the form... In the beginning Ed created MITS and intel created
the 8080 and it was ok,... :-)
<> The response time compared quite favorably to contemporary low
<> end DEC PDP-11s, and for a fraction of the cost.
Actually the Alpha MicroSystems was a s100 box in the 1979-80 time frame
that used the WD13 chipset (same as the LSI-11/pdp-11) with slightly
different microcode and it did run with the same or slightly better
performance than the LSI-11/03 it's contemporary.
<> Another problem was the unregulated power supply. Unregulated
<> +8 and +/-16VDC was run over the bus itself, right next to
<> signal lines. Every board required it's own regulation, which
<> could take 20% or more of the board space, as well as being a
<> nightmare to keep cool. If you see early pictures of loaded
<> IMSAIs, the cover was always off. This was a necessity, the
<> heat was too much with the cover on. I had to use a 16" fan to
<> keep mine running with 64KB of 2102 based static RAM (not 21L02s
<> BTW, they cost more than the fan did).
Typical of the earlier boxen. Their cooling path was poorly thought out
at best and looking at them it's was obvious. Usually some fish paper
in the right places did the trick.
<> >As for laissez-faire, I never have believed in it. It makes society
<> >too concerned about money. This is proven when complete crap hardware
<> >is released now, and people don't care because it's good _financially
An aside to this... some of the S100/SS50/trs80/apple... items from the
various third parties were quite the garbage. Some fo the suppliers were
patently ripoff artists where money was taken and nothing shipped.
Reality check. PCs today can be purchased to do real work and expected
to perform. Computers of the late '70s and into the early 80s were often
useless as shipped if they worked and required a fair amount of acumen to
configure, expand and *required* programming skills. The latter due to
add hardware and even create applications to make them useful.
For example to add a hard disk in 1980 (10mb DISCUS system was $3995.00)
and that was the drive and a s100 card. The user would have to set the
jumpers on the card for the correct IO ports to not conflict with their
system. The system BIOS would have to be rewritten to add the hard disk
and the system tracks on the floppies and the hard disks would have to be
rewritten onto the media. This assumes you had the BIOS for your system
and it was CP/M or similar... all others the bet was off. So to add a
hard disk you needed a system that was up and running, sources, could
read the sources supplied...
I often had the problem of the NS* using hard sectored 5.25 and the
supplied media was 8"!!!
Also you had an assembler, editor, debugger and knew 8080/z80 assembler.
When I went from a teltek controller to a different one... do it all over
again as the new one was totally incompatable. Far cry from an IDE disk
and setting the CMOS.
Allison
>I am completely unfamiliar with S-100 systems, so could you
please
>explain... were S-100 technologically superior to PCs (i.e. IBM
>PC 5150), or just aesthetically? As far as I know, they used an
>older processor...
S-100s started out with an Intel 8080, then Zilog Z80. That was
pretty much the end of the 8-bit version, although there were
several other variants (8085, NSC 800, Hitachi 64180, Signetics
2650, etc.). Hmm, I never recall seeing a 6502 or 6800 CPU
board. Once the S-100 was standardized around the IEEE-696
specifications the good 16 bit systems started appearing. One
of the earliest was the 8086 by Seattle Computer Labs (IIRC).
Famous because it came with the ancestor of MS-DOS, which
Microsoft later bought for their IBM PC deal. You might say all
the PC software now in existence owes its existence to the
S-100....
Anyway, there were quite a few 16-bit systems. Many 80286
variants, including a nice one by Macrotech, a dual Z80H/80286
CPU. There were several 68000s, TI 9900, National 32000, Zilog
Z8000, and a variant on the Western Digital LSI-11 bit slice
chipset called Alpha Micro. The AM ran its own multi-user
operating system, very reminicent of RT-11 (there was a strong
DEC influence there).
Was the S-100 technically superior? Well, if you go by the
IEEE-696 specifications then compared to either the XT or AT it
was quite a bit better. Maximum memory was 16MB (24 bit
address, 8 or 16 bit data path), 8 interrupt levels (open
collector! which meant multiple boards could use the same IRQ),
16 DMA levels (still better than the 7 DMA levels on the current
PC). Most 286 based systems ran up to 8Mhz reliably, some made
it to 10 or 12 Mhz (compared to the original AT at 6Mhz). Even
better, it was common practice to use static RAM memory on the
better business systems. If that term doesn't sound familiar,
cache memory on modern PCs is static RAM. The significance is
that there were no wait states or lost cycles to refresh. Think
of how fast your Pentium would run today if all 64MB of RAM was
cache, not DRAM.
S-100s were also very expandable. Motherboards usually had
between 18 and 22 slots for full sized machines. You could put
a lot of RAM, serial, and disk controllers in that many card
slots. I built custom 286 based multi-user systems that
supported 10 or more users running production business work.
The response time compared quite favorably to contemporary low
end DEC PDP-11s, and for a fraction of the cost.
S-100s were also early adopters for much of the current crop of
PC peripherals. Networking, using ARCnet at 2.5Mbps over coax.
Digital Research supported network access to disk drives using
CP/NET on top of MP/M II. No, it wasn't TCP/IP, but it still
compares quite well to a basic Netware system. Disk drives,
both the 5.25" floppy and the 5.25" hard drive showed up on
S-100s before PCs. S-100s using MP/M II could support disk
drives up to 512MB, long before MS fixed the 32MB barrier in the
XT and AT.
The S-100 did have some drawbacks, mostly from the weird control
signals the CPU had to generate (anyone remember how difficult
it was to simulate a PSYNC on a non-8080 processor?). It
suffered terribly from early failures to standardize the bus.
Many of the 8-bit systems had unsolvable compatibilty problems.
(on the other hand, it did make for some extra pocket change for
struggling college students who knew how to tune an S-100 to
make everything work :) )
Another problem was the unregulated power supply. Unregulated
+8 and +/-16VDC was run over the bus itself, right next to
signal lines. Every board required it's own regulation, which
could take 20% or more of the board space, as well as being a
nightmare to keep cool. If you see early pictures of loaded
IMSAIs, the cover was always off. This was a necessity, the
heat was too much with the cover on. I had to use a 16" fan to
keep mine running with 64KB of 2102 based static RAM (not 21L02s
BTW, they cost more than the fan did).
The single worst problem was the absolute lack of any hardware
standardization beyond the 696 specs. There were no I/O
addresses for anything. One manufacturer might use a WD 1791
floppy controller at port 7xH, another would use the NEC 765
floppy controller at address 9xH. There were no standardized
BIOS ROMs either. Systems came with some basic boot ROM for one
particular disk controller/serial interface, and that was it,
everything else was supported by drivers in the machine specific
version of the OS. A boot disk for an Altos wouldn't run on a
North Star, not even close. For those who think it an evil that
the world has standardized on the Wintel architecture for PCs,
trust me, the other choice is far worse.
>Was it just an issue of being used to them?
Sure, but then if you wanted a good hardware oriented micro with
lots of support from 3rd parties, in the mid 70s the S-100 was
the only choice. You could get a board to do just about
anything, tho you had to program it yourself. Nearly all boards
came with schematics, if you didn't like the design or it wasn't
quite compatible, you could cut traces and rewire to your own
choosing. My own IMSAI is far from a standard out of the box
model.
>As for laissez-faire, I never have believed in it. It makes
society
>too concerned about money. This is proven when complete crap
hardware
>is released now, and people don't care because it's good
_financially_
You don't like the profit motive? *gasp* That's, well, that's
just plain un-american (understandable and excusable if you
happen to be european tho).
Jack "show me the money" Peacock
<ISTR an article on alt.folklore.computers a year or so back, giving the n
<the lawyer who sent the first officially-recorded unsolicited email spam.
<he lost his account. I can't remember the details, so it might be hard t
<(and I'm not sure of the details, but 5-6 years ago sounds about right).
The landmark was right around the time I left DEC (1993).
I'd been on the 'net via their gateways since before '87. I was greatly
sadend when I the words went out the internet would permit commercial
ops.
Allison
> From: Wirehead Prime [mailto:wirehead@retrocomputing.com]
> Not all of us ISPs are evil and unconcerned with the
> Internet. I run a
> good, solid business with a 95% customer retention rate
> calculated over 4
> years. I don't do business with spammers or pornographers and have
> written my contracts so that I can immediately terminate any customer
> that violates Netiquette. I've been yelled at about that...that I'm
> ...
> Some of us who started in the early days of commercialization
> wanted the
> Internet to be like we were used to it being when we used it
> from college
> or businesses in the late 80s and early 90s. You can thank
> CompuServe,
> AOL, and hordes of know-nothing little ISPs with wads of cash to
> substitute for business sense for the current situation.
It's easy to blame novice users and get rich quick spammers, but I can't
agree with you. I look on the 'Net as evolution in action. Right now
we have the feeding frenzy of spammers drowning us in unwanted email.
The easy, and wrong, solution is to force them to stop. The right way
is to make it uneconomical for them to send spam. How? I don't really
know, I just ignore it, sort of like background static noise on a
shortwave radio.
But consider, what kind of response rate do spammers get? Now junk
snail mailers have to actually pay per piece, although at a reduced
rate. They have to make the junk mail attractive to readers so they can
get a high enough response rate to justify the mailing. Maybe we need
the same mechanism for mass commercial postings. In other words, the
ISP specifies in the terms of service that mass commercial mailings (aka
spam) are charged at the same mailing rates as the local post office,
something around 20 cents per item. Now you have a legal means to get
back if the ISP catches a spammer, because they are liable for the
contracted costs.
And just to bring it back on topic...when consumer PCs came out (IBM,
PET, Atari, Apple, etc.) those of us who built and used "real" micros
(S-100s of course) lamented that fact that the microcomputer market was
being overrun by large corporations bent on destroying the laissez-faire
market of the mid 70s. Sound familiar?
Jack "I use an IMSAI, not those toy computers" Peacock
On Apr 14, 1:36, Tony Duell wrote:
> Pete Turnbull wrote:
> > Isn't a DX11 an IBM channel interface? Originally a big cabinet with a lot
> > of flip chips and lamps? I've seen two, working.
>
> That's right.
> Where on earth did you see one of those?
A few summers ago, Leeds University were getting rid of an Amdahl mainframe and
supporting equipment, which included several PDP-11s and two DX11s. I managed
to invite myself along with a couple of friends, one of whom acquired a
complete working DX11 and one in bits, plus cables. I think there was a doc
set as well. I got an 11/73 with a much smaller 3rd party Qbus version, which
I've since passed on, as the same friend actually has a 360 which he's hoping
to get going again.
> I really must cable one of mine up again, re-read the printset, and
> figure out what on earth to use it for...
First find a System/360 :-)
Then find a lot of space with a strong floor. Jim put his in a room which he'd
prepared with a false floor. Unfortunately the materials supplier had provided
the wrong grade of board, and apparently the main unit rolled in OK, but when
it came to its proper position, there was a crunching sound, and the 360
settled a few inches as several of the castors punched through the floor
panels. Jim wasn't too pleased (he did get it fixed, though).
BTW, the little DX11-alike in the 11/73 was accompanied by a "Camtech Ethernet
QBus Interface". It's a quad-high Q-bus board, with a 68000 and a 68450 (PGA
types), a 68230, 68564, some memory, and the usual AMD ethernet chip set.
There's a 20-pin header for the ether i/f, and two 26-pin ribbon cable
connectors near a pile of 26LS30s and MC3486's, so I assume this is some sort
of terminal concentrator or PAD (there's also a 2.4576MHz xtal, which implies
standard 300/600/1200... baud rates). I was told the firmware didn't support
TCP/IP, but some other protocol. Anybody know what that would be? Is it any
use for anything? Can it be changed to use TCP/IP?
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
I have an IBM AT Multiprotocol Communications Adapter, new, in the
original carton, with the original vinyl booklet and 5.25" disk for
sale. It's only missing the cable which can easily be made from two 25
pin d-sub connectors (1M, 1F) and a piece of cable.
Anyone in the US want or need this? $10 which includes the postage. It
goes to the big dumpster in the sky if no one lays claim to it by Friday
the 10th.
--------------------------------------------------------------------
Russ Blakeman
RB Custom Services / Rt. 1 Box 62E / Harned, KY USA 40144
Phone: (502) 756-1749 Data/Fax:(502) 756-6991
Email: rhblake(a)bbtel.com or rhblake(a)bigfoot.com
Website: http://members.tripod.com/~RHBLAKE/
ICQ # 1714857
* Parts/Service/Upgrades and more for MOST Computers*
--------------------------------------------------------------------
Does anyone have an ESDI hard drive for a PS/2 Model 70? I have a
60, but want to replace it with a 120 (the other size the PS/2 came
with; I don't want to risk having an incompatible hard drive). I
don't know if others are compatible. However, this is a wide single
ribbon connector.
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
<programmer would inadvertantly spool a "binary file" to a lineprinter.. W
<had
<an individual, in the Maynard (Ma. DEC), at one point in time, spool a jo
<to
<the printer that hung off the DECsystem 1090 (serious tractor feeds on th
<unit!) that took a day and a half, and consumed 24 boxes of "greenbar" (
Likely an LP26 or lp14, serious chainsaw (a device than changes trees to
useless pulp).
<have known some of the participants, they used to reside on ML3-6... Sorr
<if
<I digressed too far off topic...
Hahaha!!! YES! than one was infamous!
Allison
<The AMD 2900 series of chips were essentially a build-it-yourself CPU.
<The main ones were :
I have about a dozen 2901s and 2911s, fun parts. Fair amount of work
to make a system around them though.
Allison
<It is an Epson LQ-500. It has a removable set of tractors, which
<mounts on top. However, they mount on the output end. This means that
<there must be paper in the tractors that is beyond the print head,
<which means that about a sheet of paper must be wasted. Could someone
<explain to me what is the idea behind this system?
Serious answer... pulling is more reliable then pushing.
Also if that thins is like my LQ5000 and the LQ570 it can be set up in
push mode.
Allison
Actually, my favorites are the ones where the tractors are right
on the platen. No jams and no wasted paper. I once had an Epson
MX-150 that jammed something awful. I got rid of that. An example
of the former is the Okidata 120, which I used with my C-64. But
to tell you the truth, I can't stand wasted paper almost as much
as wasted hardware ;)
>Most older dot-matrix printers had tractors after the
platten/printhead.
>Some of them, like my Sanders units have 2 sets of tractors, before and
>after the platten.
>
>Yes, it does mean that you waste a sheet of paper when you finish
>printing something - you have to do an extra formfeed. On the other
hand,
>I'm quite sure it saves a lot of paper due to the reduction in the
number
>of paper jams. A lot of 'push' type tractors seem to be great at
mangling
>paper...
>
>-tony
>
>
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On Apr 14, 12:04, Tim Shoppa wrote:
> > ISTR an article on alt.folklore.computers a year or so back, giving the
name
> > of the lawyer who sent the first officially-recorded unsolicited email
spam.
>
> I think you're talking about Canter and Siegel, right? While this
> wasn't the "first" spam, Canter and Siegel's "GREEN CARD" postings
> are among the best well-known, and in many ways the most irritating.
> (Canter went on the talk-show circuit after the spam disaster to
> promote his book which claimed to show others how to succeed in
> internet marketing.)
Thanks, Tim, that's what I was thinking of. And thanks to whoever dug out the
posting (sorry no attribution, I hit "delete" a bit too quick). Seems my
memory was close but not wholly accurate. How unusual :-)
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On Apr 14, 23:07, Tony Duell wrote:
> Ouch!!!. Even my standard test for floor loading wouldn't have found that
> (= Jump up and down hard. If the floor doesn't give way, put the machine
> on it and jump up and down again. If it's still OK, it'll probably stay
> that way).
Jim now has the flooring from our Department's old machine room -- and now I
know why those floor panels are so heavy :-)
> > BTW, the little DX11-alike in the 11/73 was accompanied by a "Camtech
> > Ethernet QBus Interface".
> The only thing that reminds me of is the Camtech JNT PADs and iso-ether
> PADs used in UK universities as part of the JANET network. I've not got
> any, alas (I'd quite like one...), but I seem to remember that at least
> the JNT pads were Z-80 based and had a synchronous serial port connection
> to the outside world talking some kind of X25...
We had several, but they all got cannibalised. They were indeed Z80-based, and
had lots of SIOs, DARTs, and a few PIOs in them too. Neat cases as well.
> I have no idea what it talked instead of TCP/IP, but it'll probably be
> something that was common in the UK at the time. Any ideas? I can look
> back through PERQ and Torch XXX manuals to see if anything leaps out..
I've no idea. I imagined that Camtech made other ethernet stuff, and if they
could make such a good-looking QBus ethernet i/f I thought there must be more
around. I've never found any, though, nor have I ever found anyone who could
tell me much about long-gone Camtech (apart from JNT PADs).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
I looked at the pictures, and double checked my Olivetti M24, recently
obtained from Andrew Davie. They are the same machine.
This one also has a dead power suppy but none of the corrosion. The fan
works because it is mains powered, 240v in this case.
Hans Olminkhof
-----Original Message-----
From: David Williams <dlw(a)trailingedge.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Tuesday, 14 April 1998 15:40
Subject: AT&T 6300 PSU Question
I went to power up my AT&T 6300, which hasn't been up for about 4
years, and noticed that the PSU fan was coming on but the drives and
motherboard didn't seem to be getting power. I opened up the system
and was surprised to find the power supply was corroding. Now I'm
not a PSU expert by any means so this was unexpected. The upper
motherboard appears to be ok but I haven't checked the lower
motherboard yet. It appears I can pull the PSU out and replace it
but I'm curious as to why it began corroding in the first place. You
can see pictures of it on my web site on the AT&T 6300 page or at:
http://www.trailingedge.com/~dlw/comp/images/attpwr1.jpghttp://www.trailingedge.com/~dlw/comp/images/attpwr2.jpg
[SNIP]
>shortwave radio.
Speaking of shortwave, imagine if the FCC authorize commerce on
ham radio! Ugh...
I am completely unfamiliar with S-100 systems, so could you please
explain... were S-100 technologically superior to PCs (i.e. IBM
PC 5150), or just aesthetically? As far as I know, they used an
older processor...
Was it just an issue of being used to them?
As for laissez-faire, I never have believed in it. It makes society
too concerned about money. This is proven when complete crap hardware
is released now, and people don't care because it's good _financially_
>And just to bring it back on topic...when consumer PCs came out (IBM,
>PET, Atari, Apple, etc.) those of us who built and used "real" micros
>(S-100s of course) lamented that fact that the microcomputer market was
>being overrun by large corporations bent on destroying the
laissez-faire
>market of the mid 70s. Sound familiar?
> Jack "I use an IMSAI, not those toy computers" Peacock
>
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I have a minor problem with a dot matrix printer, and its feeder.
It is an Epson LQ-500. It has a removable set of tractors, which
mounts on top. However, they mount on the output end. This means that
there must be paper in the tractors that is beyond the print head,
which means that about a sheet of paper must be wasted. Could someone
explain to me what is the idea behind this system?
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
> And to make matters even worse, it was a husband and wife lawyer team!
Birds of a feather, um, make that vultures, flock together...
Jack "birdbrain" Peacock
> From: Max Eskin [mailto:maxeskin@hotmail.com]
> there must be paper in the tractors that is beyond the print head,
> which means that about a sheet of paper must be wasted. Could someone
> explain to me what is the idea behind this system?
At one time nearly all tractor feed printers pulled instead of pushed.
Demand documents (i.e. tear off right above the print head) was not a
concern for most printers. Reports were printed in batches, then
separated by operators. Also, the paper was less likely to jam if you
pull it through the paper path, rather than try to push it through.
Ever see a paper jam on a 1200LPM chain printer? The operator could
spend a good 15-20 minutes clearing out bits of shredded paper.
Computer time was more expensive than the paper, no one cared if a few
pages got wasted for form feeds.
Jack peacock
On Apr 14, 11:06, Allison J Parent wrote:
> Try about 5-6 years and it was there before but you could get the offender
> tossed before that. Also When AOL opened to the net it seemed to add to
> the fray.
ISTR an article on alt.folklore.computers a year or so back, giving the name of
the lawyer who sent the first officially-recorded unsolicited email spam. IIRC
he lost his account. I can't remember the details, so it might be hard to find
(and I'm not sure of the details, but 5-6 years ago sounds about right).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On Apr 14, 0:40, David Williams wrote:
> Subject: AT&T 6300 PSU Question
> I went to power up my AT&T 6300, which hasn't been up for about 4
> years, and noticed that the PSU fan was coming on but the drives and
> motherboard didn't seem to be getting power. I opened up the system
> and was surprised to find the power supply was corroding.
> You can see pictures of it on my web site on the AT&T 6300 page
Jason's comment about liquid sounds about right. It looks more like something
was spilt onto it, than as if something self-destructed. Anyway, it's usually
electrolytic capacitors that self-destruct in that way, and that normally
happens when there's a voltage there.
> Any ideas? Also, anyone have a spare PSU? I don't really want to go
> buy another AT&T 6300 just for this but suspect the PSU won't be easy
> to obtain otherwise.
I'd attempt a repair, or at least some further investigation.
The case looks pretty yucky but from the pictures, the physical damage might
not be that great. I'd take it apart and attack the case with a wire brush or
steel wool, and a very light touch of oil or WD40. The terminals don't look
too bad at all, a little brushing (stiff toothbrush preferred, or a brass wire
brush or fine steel wool) and a little WD40 should work wonders. Make sure you
wipe off any excess WD40, though.
Depending on how bad it is inside, it might be worth washing, but do make sure
that (1) any capacitors are discharged before you get it wet, and (2)
everything is *completely* dry before you try applying power! Again, a
toothbrush is a useful tool.
In many similar PSUs, the fan is driven from the 12V line. If that's the case
here, it implies that at least part of the circuitry is working, which is very
encouraging. Perhaps only the 5V line is dead. It's hard to suggest much more
without more information, and without seeing the inside.
If you do try anything, apart from the obvious precautions, be aware that there
are some very high voltages inside switch mode PSUs, as high as 300V. Also,
many PSUs won't operate correctly without a load on at least the 5V line; at
best, they won't regulate properly, at worst, they can be damaged.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
today at goodwill I found a Advance Micro Device AM2900 Evaluation &
Learning Kit in the it's box (very nice design on it) with one worksheet.
the unit was only $5.
Sorry about the extra public traffic (and this one too). I didn't look
at the "reply to" on Charles' message.
--------------------------------------------------------------------
Russ Blakeman
RB Custom Services / Rt. 1 Box 62E / Harned, KY USA 40144
Phone: (502) 756-1749 Data/Fax:(502) 756-6991
Email: rhblake(a)bbtel.com or rhblake(a)bigfoot.com
Website: http://members.tripod.com/~RHBLAKE/
ICQ # 1714857
* Parts/Service/Upgrades and more for MOST Computers*
--------------------------------------------------------------------
On 1998-04-12 classiccmp(a)u.washington.edu said to lisard(a)zetnet.co.uk
:I think we all would expect all the
:subscribers to this list (and the other lists as well) to conduct
:themselves in a civilized and honourable way [...]
rotflmao
On 1998-04-12 classiccmp(a)u.washington.edu said to lisard(a)zetnet.co.uk
:... I only hope that there is a "silent
:majority" who does not speak but disapproves them and this is the
:only reason that keeps me from leaving conmans and their helpers to
:their destiny by leaving this list.
please, since you clearly haven't found any, assume you are wrong and
bugger off.
--
Communa (together) we remember... we'll see you falling
you know soft spoken changes nothing to sing within her...
This is new. Just brought the uVAX up again. I sent ONE message to Usenet
mentioning the address.
I now made it to some luser's spam list!
This is the new thing...
The spam appears to be in Japanese?
I guess this will be the first spammer I mail that can UNDERSTAND what they're
being mailed! (A-CNH)
The question is, just out of curiosity, when did Usenet deteriorate to the
point that spamming started?
Was it around the time AOL let people on Internet? :)
(J/k!)
-------
My PS/2 Model 70 is a 386, released around 1990. It is the most
recent machine I have seen to have ROM BASIC, with IBM DOS 3.3's
BASIC.EXE jumping just fine.
>
>Here's one I've never run into, oddly enough. IBM PCs 5150 throrugh
5170
>had the BASIC ROM and BASIC.EXE and BASICA.EXE included with PC-DOS
through
>4.0 just jump to the code on the ROM.
>
>Later models (PS/2s) still have the Cassette BASIC, but don't seem to
be
>able to run the PC-DOS BASICs. Did IBM break the BASIC ROM after the
5170
>model?
>
>--
>David Wollmann |
>dwollmann(a)ibmhelp.com | Support for legacy IBM products.
>DST ibmhelp.com Technical Support | Data, document and file conversion
for IBM
>http://www.ibmhelp.com/ | legacy file and media formats.
>
>
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Here's one I've never run into, oddly enough. IBM PCs 5150 throrugh 5170
had the BASIC ROM and BASIC.EXE and BASICA.EXE included with PC-DOS through
4.0 just jump to the code on the ROM.
Later models (PS/2s) still have the Cassette BASIC, but don't seem to be
able to run the PC-DOS BASICs. Did IBM break the BASIC ROM after the 5170
model?
--
David Wollmann |
dwollmann(a)ibmhelp.com | Support for legacy IBM products.
DST ibmhelp.com Technical Support | Data, document and file conversion for IBM
http://www.ibmhelp.com/ | legacy file and media formats.
<years. It happened shortly after NSF lifted the ban on commercial traffi
<and the 'net became better known to the public. Sure enough, a bunch of
<marketeers with more greed than brains saw Usenet as a vast new territor
<instead of what it was intended to be.
Try about 5-6 years and it was there before but you could get the offender
tossed before that. Also When AOL opened to the net it seemed to add to
the fray.
<The spam started. It has been throttled back to a degree, thanks largel
<to the efforts of the anti-spam crowd (consisting mainly of sysadmins), b
I haven't seen it slow. I've just about stopped posting in newsgroups
and stay away from many web pages where they appear to do address capture.
I don't even write in maillists (alt.sys.PDP8 to name one) that echo to
newsgroups for the same reason. I'm tired of getting junkmail from
some_bimbo(a)earthlink.com that really isn't earthlink and is likely a man.
Even with reducing presence and using munged address in most places I
still get the crap.
I can live with commercial but the sex for sale is unacceptable.
Allison
I don't have graphical internet access, so I can't see the pictures,
but could it be that electrolyte spilled from one of the
capactiors?
Just an idea...
>
>On 14 Apr 98 at 1:57, jpero(a)cgo.wave.ca wrote:
>
>> Wow! Looks like something have exploded inside and left there,
>> eating away those metals...or a cat had sprayed it or mouse have
>> known to get inside via a open card slot and pee. And leave rice
>> sized BM's inside. This kind of corrsion looks like much liquid have
>> left in there, judging by the patterns of corrsion. Did something
>> have dripped on that computer? High humidry is out, you have good
>> metals anywhere else because I had some that was stored inside a
>> closet with high humidry and came out heavily corroded clone power
>> supply box.
>
>I thought about that but the system has been sealed fairly well since
>I put it in my climate controlled storage space. Still, it does look
>like something was spilt on it. No open slots or anything so I don't
>know what could have gotten inside.
>
>I have another AT&T PSU I've been using to power the hard drive on my
>Amiga 1000. I may find a new power supply for the hard drive and use
>that one as a replacement for the corroded one. Still, it would be
>nice to know if something was dumped inside or the PSU itself
>released something.
>
>> BTW, what kind of camera and type of lens used you have used to take
>> this pics? That's very close up work and very sharp.
>
>I used a Kodak DC210 digital camera I borrowed from work. It's an
>$800 camera so I'd hope it would take decent pictures. :-) I'm using
>it to redo most of the images on my web site. It's a great camera.
>And those images were taken at it's lower resolution.
>
>-----
>David Williams - Computer Packrat
>dlw(a)trailingedge.com
>http://www.trailingedge
>
______________________________________________________
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I recently received a BULL XPS 100 mini frame from out local college with
all the manuals and disks.. etc It is a unix box, and I was curious if
anyone has had any experience with these things? And if they can point
me in the right direction to get this thing to boot :>
Thanx
Kenny
At 08:32 AM 4/11/98 PDT, you wrote:
>Wait a second, ARE there private newsgroups on this topic? I thought
>it was just an idea everyone proposed but never did...
Not that I know of. If there are, they're not letting me in. (A good idea
anyway, I suppose.)
>>It has. It comes up every now and then on every mailing list. What
>>usually happens is that those who want a newsgroup go off a create a
>>newsgroup, and the ones who can't access or don't like newsgroups stick
I was speaking of mailing lists in general. As in the Land Rover list,
which after many such suggestions finally split into Series and Coil Sprung
lists, and now also has a newsgroup.
Sometimes it goes the other way; I suspect rec.equestrian was around long
before the dressage list.
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
At 12:28 PM 4/12/98 +0000, you wrote:
>> I promise that we CAN. I didn't say anything about willing to. However,
>> should I come across one, you'll be the first to know.
>> Tim D. Hotze
>> >Is this a promise?
>> >
>> > I'm sure that we could find a TRS-80 model 1 CASE
>> >> somewhere for you.
But if you did, would you want to risk your own reputation by sending it to
him? Goodness knows, it might not have the right serial number or
something, and then you'd be branded a con man for life! 8^)
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
J. Maynard Gelinas wrote:
> OK, This is mildly on topic. My monitor is an HP 1097C, making
> it at least 10 years old. However, I am using it with a modern PC, so
> that's where the 'on topic' issue gets a little iffy. I'm sure there
> are plenty of people here who can answer this question. A pointer to
> a FAQ would be most welcome.
Here's one interesting URL:
http://rugmd0.chem.rug.nl/~everdij/hitachi.html
I've seen others as well but that was the one I made a bookmark to. :-)
> These old monitors are Fixed frequency, unlike our modern
> monitors which multisync. The 1097C supports only a 78.125 khz
> Horizontal Scan Rate and a 72hz Vertical Refresh Rate. Now a couple
> of years ago I foolishly bought one of those cards by Mirage
> (www.mirage-mmc.com) which is supposed to be a 'fixed freq video
> card'. Actually, it's an OEM Diamond card, basically an S3/968 video
> processor with an IBM 52x RAMDAC - ala Diamond Stealth VRAM. The
> fixed Freq hacks are basically a resistor (and a jumper selection) to
> drive sync over green, and a homebrew PROM to skew the VESA
> frequencies for several video and text modes.
Hmmm, interesting. Photon also makes fixed-freq. boards, and I was tempted to
get one for an old SuperMac monitor I have. I also once attempted to fix a
batch of Moniterm monitors that had various problems, and the one board I
found to use with them in Windows was a Vermont Microsystems model that cost
way too much to begin with, and is now no longer made. There was also no
driver later than Windows 3.1, so my dad has it now since he still has a slow
486. Anyhow, I thought Photon's boards were probably better than Mirage's, I
forget why. They are at www.photonweb.com I think, but I can't seem to get
there at the moment.
> It works, but Mirage hasn't been too helpful with getting a
> variety of XFree86 modelines, even though they claim to support Linux
Darn, shame on them.
> and XFree86. They give out _one_ modeline for 1280 x 1024, which they
Well at least it works eh? Can you at least upgrade the VRAM to get more
colors, or did you want low-res for some other reason?
> swiped from the XFree86 distribution in 'Monitors.txt'. For Windows
> and Dos, they give out a video driver which seems to work just fine.
> It will even display 320x200 full screen (Quake works great in DOS!),
> and boots to a functional 80x24 col text mode. How the hell do they
> do this?
>
> Here is how I'm calculating my video modes based in the
> XFree86VideoModes HOWTO (found in every Redhat 5 distribution):
You understood what they said, that your horizontal line includes enough
"dots" to allow time for the gun to sweep back to the beginning of the next
line? So to get 1280 dots across, you might need to allow 1350-1400ish
dot-clock-periods per line (or maybe even more).
(dots/sec) / (dots/line) = lines/sec = lines/frame * frames/sec
For example:
if you want 1024 lines, allow around 1150 total lines (to allow time to sweep
back to top-left between frames); so
1150 lines/frame * 72 frames/sec = (x dots/sec) / (1350 dots/line)
now solve for x to get the dot clock, and to double check the formula, make
sure that all the units cancel out.
x dots/sec = 1150 lines/frame * 72 frames/sec * 1350 dots/line
yep, line / line * frame / frame * dots / sec = dots / sec
and you need a dot clock of 111,780,000 dots/sec
>
> Dot Clock Per Second
> Total Horizontal Pixels Per Line = --------------------------
> Horizontal Scanning Rate
This is right, dots / line * line / sec = dots/sec
>
> Since my refresh rate must be at 72hz to sync with the HP1097C:
>
> Dot Clock
> Refresh Rate = -------------------------------------------------
> Horizontal Frame Length * Vertical Frame Length
frames / sec = (dots / sec) / (dots / line * lines / frame)
= (dots / sec) / (dots / frame)
= frames / sec
yep
>
> So, it's really more constructive to think of this as how many
> pixels _total_ do I need to display in order to get a 72 hz vertical
> scan rate with any arbitrary dot clock? In this case I need
>
> Dot Clock
> Total Pixels Per Frame (HFLxVFL) = -------------
> Refresh Rate
You did algebra on above, correct
>
> Since I know my Horizontal Pixels Per Line, I can use this to
> determine the number of vertical lines which will support a 72 hz
> refresh rate.... hmmm, this is where things get sticky. We'll start
> with a DCL of 10Mhz...
Why? That is too slow a dot clock to be useful. You should work backwards -
figure out what resolution you want, find the corresponding dot clock, pick
the closest supported dot clock to the one you calculated, and then calculate
forward again to figure out what resolution you can actually get. You can
also play with the blanking intervals, because the monitor has a minimum time
that it takes for the gun to scan back to the beginning of the next line (or
next frame), but no maximum time. If your supported dot clock is a little too
slow, you can waste the time in the blanking interval to keep a standard
resolution, or else optimize the resolution to use up all the available
time/line. But with a fixed frequency monitor, you must also keep the
horizontal and vertical scan rates in "range" - however wide that happens to
be. So really, with those two constraints plus your quantized available dot
clocks, that's why "fixed frequency" also means "fixed resolution". If the
monitor was designed for 1280 x 1024, the card must output about that many
dots in each frame and at the correct frame rate. You could output half the
dots per line, and also halve the dot clock, and halve all the other values
(front porch, back porch, vertical blanking interval, etc.) but if you tried
to also cut the vertical resolution in half, you'd violate the line rate
constraint. So as you say below, line doubling makes a lot of sense; you
could simulate 640 x 480 on a 1280 x 960 screen by halving the dot clock and
line-doubling each line. Text mode can be simulated by custom programming on
the graphics chip, so that it actually produces dot data at 640 x 480.
Keep in mind the monitor will have "total bandwidth" limitations too - it
might not be able to accept too fast a dot clock even if you don't exceed the
horizontal scan rate or frame rate.
<second message>
> BTW: no one responded to this message, so I guess no one
I'm sorry, I must have missed it. Normally that subject would catch my eye.
:-)
> knew the answer. I received a responce to a USENET post about
> this and thought there might be some interest in the group.
> The VGA spec supports 'doublescan' mode for low resolution
> compatability with CGA apps. This essentially forces the card
Cool, makes sense, I didn't know that was a standard.
I used to have a DOS CGA simulator for the Hercules card, several years ago,
that
must have worked this way also; simulating 640 x 200 on a 720 x 400-something
display. The displayable area was smaller too, so evidently they only used
640 of the available 720 dots across. It was very useful for playing old CGA
games on my mono card anyhow.
> to draw each horizontal line twice, thus doubling the refresh
> rate (or your vertical resolution in half at the same refresh
> rate) at any arbitrary horizontal scan rate. Well, some
> chipsets (like the 968, Matrox Millenium, and most ATI
> chipsets), allow for tripplescanning which does exactly what
> one would expect... it scans each horizontal line three times
> before skipping down to the next line, thus allowing one to
> drop down to a third of the vertical resolution at the same
> refresh rate (same horizontal rate always, of course).
Hmmm, so 1024 / 3 = 341, 960 / 3 = 320, I don't see how that would be very
useful since there aren't many (any?) modes that have vertical res. in the
320-340ish range. Maybe it could be stretched a little to get 640 x 400.
Quad-scan would be useful for doing 320 x 200, or they could just be wasteful
with memory and do 4 pixels in VRAM for every pixel and get 640 x 400 out of
it.
800 x 600 would just be plain nasty. :-)
>
> OK. XFree86 and SVGAlib don't support tripplescan mode, but
> they do support doublescan mode because it's part of the VGA
> spec. Tripplescan is vendor specific, and so thus is enabled
> in different ways for each chipset. I'm attempting to hack
> svgalib to support tripplescan for the S3/968... waiting for
XFree you mean, or svgalib?
> the 968 docs to arrive so I can find the register and register
> values to set for my adapter. The rest seems fairly easy, just
> hack in parsing for 'tripplescan' on the modeline and such.
>
> Why does this matter to you? Well, if you have an Hitachi
> HM-4119, HP1097C, or somesuch fixed freq monitor, getting it to
> work under Linux is pretty easy once you know the trick. Why
> buy a $1500 monitor when you've got a perfectly fine one
> sitting on your VaxStation 3100? Well, for the purposes of
> this list, why not just use the 3100 as the xterm... but that
> defeats the purpose of this message. ;-)
Yep, I've been wanting to do this for years. I did it briefly with that
Vermont card (and kept the hercules card also, for text mode, because the
Vermont card made no attempt to support any standard modes at all; it was
really intended to be a secondary display for CAD) but couldn't do any newer
Windows or X with it. It also had an interesting high-level proprietary
command language for drawing the primitives; I got the impression from its
sketchy docs that you could actually send textual commands to its I/O port and
it would interpret them in real-time. That and being an ISA card made it
kindof slow. And it only had enough VRAM to do 16 colors, and Vermont wanted
an arm and a leg to upgrade to 256 colors.
My SuperMac monitor worked fine with my ATI All-in-Wonder, but only in Windows
95, for which there is a nice driver that lets you tweak every parameter.
Tweaking similarly might be possible, if harder, in X, but I haven't tried it
yet. Unfortunately the Win95 ATI driver won't tell me the numbers to plug
into X modelines; I wish it would, but there are just these arrow buttons on
the screen to adjust position, size, etc. My experience has been, if you are
in the ballpark and the monitor is behaving itself, you can tweak it a little
bit to adjust size and position; but then all of a sudden it will just go
bonkers, and to get back to where you were right before that, you have to
overshoot and then edge your way back (not moving the mouse, because
you can't see the on-screen button anymore!) So reproducing the same results
with xvidtune's tricky interface would be difficult.
Someday, maybe somebody will produce a video card with a video-scaling chip
built-in, so that you can multiply dots by something other than a whole
number. This is the sort of thing that's already being done for LCD video
projectors, video digitizers that can put the image into an arbitrarily-sized
window (like my All-in-Wonder), the digital HDTVs now being designed, and
maybe even some of the better laptop displays. I don't see why if they can do
it for TV input they can't do it on the output signal as well. As the dot
clock asks for each output dot, the chip would just have to take into account
the colors of the adjacent dots, and blend smoothly; so to avoid having to
read VRAM at, say, 9x dot clock, it would have to have some fast registers to
store the values of the adjacent dots temporarily, and it could then read VRAM
at a mere 3x dot clock. Or, it could store 3 lines in its fast memory and
read the line past the next one during each horizontal blanking interval.
Maybe the need for fast VRAM is the limiting factor; no, because actually
scanning at 1280 x 960 requires 4x the speed of scanning at 640 x 480, whereas
simulating 640 x 480 at a dot clock to achieve 1280 x 960 only requires
reading VRAM at 3x the rate. So I don't know why this hasn't been done.
Maybe Photon does this, I'm not sure.
I think I'm going to post this on a newsgroup or two and see if we get any
better answers.
--
_______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)bigfoot.com
(_ | |_) Shawn T. Rutledge http://www.goodnet.com/~ecloud
__) | | \_____________________________________________________________
<today at goodwill I found a Advance Micro Device AM2900 Evaluation &
<Learning Kit in the it's box (very nice design on it) with one worksheet
<the unit was only $5.
I must be looking in all the wrong places. That's only my list for SBCs,
next time.
Allison
