Good firewall prog?

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

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.

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".

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:

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.

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

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

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.

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.

I thought it was the Star Trek connection.

NCC-1701

Now, can you fit NX-01 in there?

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

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

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

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

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

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 :-).

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.

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.

The original 16KB chips were different (I seem to remember them requiring THREE power supply voltages). The 64KB and 256KB chips were very similar.

I had a 128KB RAM expansion cartridge for the C-128 (this used 16 64KB chips). There were some people who converted them to 512KB (using the