Good firewall prog?

Then explain away the 1701 error code in the IBM PC family, and the Commodore 1701 monitor. ;-)

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Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell
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You should have used the simpler version:

print "hello" goto

If you didn't use a line number, the first line was line zero. If you didn't specify a line number, GOTO goes to line zero.

I used to have fun with a simple one line program that changed the border, screen, and text colors with pokes, add 1 and loop. It caused the screen to flicker like it had a bad PLA chip. It all fit on one line if it was typed in with tokens and you left out the line number at both ends.

BTW, I wrote a disassembler for the OS ROMs in Commodore floppy disk drives in Commodore Basic. I used a bunch of "On - Gosub" commands to direct different op codes to different routines where it would get any data bytes. It read the ROM in the drive, and wrote the disassembled code to a floppy in the same drive. I ran it on all the different Commodore drives, as well as the third party drives. By comparing the routines with the published data on a couple drives were were able to comment the code for most of the drives.

Do you remember Disk Doctor (Sector editor) for the Commodore computers? I modified it to recognize the 1581 and changed the screen layout and colors. I put a copy on a floppy disk and used the program to edit itself. You should have seen the looks when I demonstrated it at a Commodore computer club meeting in front of a couple hundred members. They were all laughing as I hooked up the 1581 drive, then they all shut up when the program recognized the drive and could display all sectors on the map. they demanded to know where I got it. I just smiled and told them I knew the programmer who wrote it.

I had another program that would check the write protect tab and invert the bit in the drive's memory. We were going to give away a floppy fully of shareware at a meeting that fell on april first with a big notice not to write protect the disk. If they did, the menu program would detect it and reformat the disk. They never let me have any fun! :(

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Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

I read in sci.electronics.design that Michael A. Terrell wrote (in ) about 'Good firewall prog?', on Wed,

14 Sep 2005:

1701 in Roman numerals is MDCCI. So it's obvious.
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Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
Reply to
John Woodgate

The C64 was (and still is) a great machine for hacking... the old trick of setted up interrupts on given video scanlines and then precisely changing the VIC's registers created all sorts of incredible effects. (I always like the trick of switching the chip from 40 column mode to 38 column mode right as the video display was cranking out column 39, thereby never triggering the state change to outputting a border, thereby removing the borders from the edges of the screen! Oh, and of course getting more than 8 sprites by reloading all the sprite pointer registers every 64 pixels was fun...)

Back in that same era, do you remember Copy II PC for the Apple II? That think would copy a full ~180k floppy from one disk to the other in something like 30 seconds flat -- absolutely amazing given that there was no actual disk controller chip to speak of and everything was going through the 1MHz CPU.

Reply to
Joel Kolstad

I didn't know that then, but I learned it later. Also, if GOTO is followed by something non-numeric, 0 will be assumed. I would write a joke program where line 0 had PRINT "IT'S HOT IN HERE", and you could then enter GOTO HELL.

I did it in machine language, where you could change the colors many times during the screen refresh interval. This would produce a striped border. That was one of my several strange-looking programs I had for the C64.

I did too.

Once someone gave me a "10-second format" program that would run without any prompts, instantly formatting the disk of software you were running things from.

I wrote one that claimed to make the C64 run 10 times as fast, but with an unusual side effect. It would generate a strong magnetic field that interfered with the deflection coils in your monitor. It would blank the screen, and take a minute or so to initialize. The text would come back on - upside down. It's actually a harmless program that used a programmable character set.

I actually used an upside-down monitor for debugging that.

Once, I gave a talk at a local user group, on reversing the NEW command. This involved manipulating a pointer to a memory location I called SOB (the start of the BASIC program).

The strangest, most useless addition to BASIC PLUS was the NOPRINT command. It's function was to suppress the effect of print for a selected number of characters. For example:

NOPRINT 1:PRINT "THE"

Would print "HE".

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102 days until the winter solstice celebration

"Today, the theory of evolution is an accepted fact
for everyone but a fundamentalist minority, whose
objections are based not on reasoning but on
doctrinaire adherence to religious principles"
-- James D. Watson
Reply to
Gary H

Actually it was more likely the double sided drives that ended the flippy idea. I used the Wangco drives in 1979 that were built with sensors on both sides so the media jacket did not need punching. About that time there was also the TRS-80 Users Group meeting at Mile Square Park in Fountain Valley, CA with over 1,200 members from all over the world. The punches were available there for those who did not have flippy drives and did not know how to just use the paper punch with a piece of paper between it and the cookie (media) to protect it from being scratched. We had guest speakers from many of the drive media, etc. manufactures, software developers, etc. to the monthly meetings where as many as 800 members would show up. Then IBM fever hit and the club eventually went the way of the dinosaur. Sigh.

James

Rich Grise wrote:

Reply to
James

Did you ever use any of the copy software for the 1541 drives that let you make copies without a computer? You connected the first drive and booted the program, plugged in the second drive and pressed a key, then unplugged the cable from the computer. After that, you put the original in device 8 and a blank in device 9 and let it copy the entire disk. You could make copies all day long, till the power fluttered, or a drive crashed.

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Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

Late 80's and a $5000 SCSI 200MB hard drive - the test rig was on the bench running when a manager came in, picked up the running hard drive and said "What's this?", didn't wait for the answer and walked out. Needless to say it had crashed and died.....

Ken

Reply to
Ken Taylor

I used to be involved in a C64 user group, where they used such software to make copies from a group library. Sometimes they used the

1541, and sometimes they used the MSD SD-2 (dual drive).
--
101 days until the winter solstice celebration

"Today, the theory of evolution is an accepted fact
for everyone but a fundamentalist minority, whose
objections are based not on reasoning but on
doctrinaire adherence to religious principles"
-- James D. Watson
Reply to
Gary H

The C128 (which used a very similar 40-column video chip) has limited BASIC support for that. You could have part of the screen in text mode and part bitmapped.

Of course, the sprites would be limited to that particular vertical area of the screen. However, you could still do interesting things with them.

--
101 days until the winter solstice celebration

"Today, the theory of evolution is an accepted fact
for everyone but a fundamentalist minority, whose
objections are based not on reasoning but on
doctrinaire adherence to religious principles"
-- James D. Watson
Reply to
Gary H

Are you recommending this? If so, you could make it easier for people to find it. While it's easy to find the Agnitum website, it's wanting you to BUY a program. In these cases (when a company sells a program, and also has a free version available), they can make the free version hard to find. Some help would be useful.

--
101 days until the winter solstice celebration

"Today, the theory of evolution is an accepted fact
for everyone but a fundamentalist minority, whose
objections are based not on reasoning but on
doctrinaire adherence to religious principles"
-- James D. Watson
Reply to
Gary H

I thought it was the Star Trek connection.

NCC-1701

Now, can you fit NX-01 in there?

--
101 days until the winter solstice celebration

"Today, the theory of evolution is an accepted fact
for everyone but a fundamentalist minority, whose
objections are based not on reasoning but on
doctrinaire adherence to religious principles"
-- James D. Watson
Reply to
Gary H

I have used floppies since the CP/M days, and that includes "flippies" and never had problems concerning dust related to floppies. There was only one time that i had to deal with dust - a customer called and said that he could not get his computer to boot (DOS, boot floppy). I checked it out, and found the whole inside of the computer filled with dark, fluffy "dust bunnies". It took over a half an hour to clean it out (it had acumulated over a

2 year period), and the floppies themselves weer OK, only the drives needed some cleaning. On a semi-related note, the only time i had increasing floppy read errors, was on my original IBM PC/XT (with the cassette port), where the clamp cons (for the floppy) got so worn, that it did not reliably hold the plastic disk inside the floppy's covering, so that it would spin properly.
Reply to
Robert Baer

Color me both stupid and ignorant. How does "1701" or "MDCCI" relate?

Reply to
Robert Baer

Hope you dumped the drive on his desk, telling him to use it as a $5000 boat anchor.

Reply to
Robert Baer

Our Commodore club (Orlando) had one of the MSD SD_2 drives as club property. Someone put the automated copy software into an EPROM for the empty memory location on the PC board but the club was too cheap to buy the chip for theirs. I had one of the MSD SD_2 drives in the Commodore collection I lost a few years ago. I had almost every computer they made,. outside of the Amiga line. I still have some of the old dual

8050 type drives with the IEEE-488 interface, along with a pile of 4032 printers.
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Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

Gary H wrote in news: snipped-for-privacy@4ax.com:

Reply to
Ingeborg

Looks like you're right. I dragged out the C source code of my "car" (CPM archiver, like tar), written circa 1980, and it agrees. So they musta been 256KB... I used to get access to the 8" floppy drive in the VAX to move stuff to/from CPM :-).

Reply to
Clifford Heath

I converted a lot of IBM 256 KB motherboards to 640 KB. There was a empty IC socket, and a jumper between two pads left off the 256 KB version. I was recycling 256 KB chips by the thousands, and used a lot of them for the conversions. The 64 KB chips I pulled were used to repair C-64 computers. I bought the DRAM tester kit from StarTek to sort the used chips by actual speed because the 256 KB chips were from junked Unisys boards that were hand screened to be used at higher than marked speeds.

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Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

PC/XT motherboards, sure. We did hundreds of 'em (access to free memory ;-). The original PC (5150) motherboards had 64KB maximum. The later PC motherboards had a 256KB max. PC motherboards were different than the PC/XT boards and couldn't be upgraded past 256K without making a complete mess of the board.

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  Keith
Reply to
Keith Williams

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