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Posted By

Lavina
on 2024-03-21
16:31:47
 lost LVN demopart and Gotu Monitor

I've just remembered out of the blue that I had one demo part ready in 1991 that I cannot find anywhere among my listed releases... Most probably it was done for GOTU MEGADEMO I but was not included by KIKI. I only remember that probably it had a gotu logo at the top of the screen drawn like as if it were cut out of a motherboard, you know, circuits and chips, and in the middle there was an animation of a "sphere" with two twisting electric sparks in it. At the bottom of the screen there was probably a scroll. Anyone, does it ring a bell??

The funny thing is that I count 3 parts in the megademo that I contributed and I have 4 parts listed on my.... khhm.... workcassette.... I still have that tape, I just can't find a suitable crt ATM. My led TV cannot find the signal. Thanks. Meanwhile, sad photo from a lost first battle:



Posted By

JamesC
on 2024-03-18
18:29:34
 Re: lost LVN demopart

OT: what do we call a Plus/4 that is missing its '4' key?

Would we call it a Minus/4?

Posted By

Csabo
on 2024-03-18
19:17:49
 Re: lost LVN demopart

OT: A Plus/4, minus 4? Wouldn't that be zero? happy

I don't think I remember seeing such a part, but I really hope you find it!

Posted By

MMS
on 2024-03-18
19:41:18
 Re: lost LVN demopart

Such a strange photo. I know it is due to distance and optical illusion, but the closer one looks much wider than the Plus/4 in the center. happy

Posted By

gerliczer
on 2024-03-19
02:44:14
 Re: lost LVN demopart

@Lavina: RetroTINK? Framemeister? Open Source Scan Converter? Lotharek's Medusa? Neither of them will search for your part but may give you a way to find it. happy

Obviously, all these devices need a video cable which, in itself, may solve your display problem. And those are cheap and common.

Posted By

Lavina
on 2024-03-19
04:01:00
 Re: lost LVN demopart

I was thinking about digging up another relic from the past, a VCR, feed the RF to it and then let the TV find that signal.... It even has composite or scart, so hopefully it will be a quicker solution... My plus4 config has not been assembled for several decades and last night I did not have the means to get the aforementioned technological marvels. wink Maybe I could also try loading from tape and saving to SD1541-II. blind... I just would not see any load errors... But I know the exact tape counter location of the target part... I'll have more time tonight.

Posted By

gerliczer
on 2024-03-19
04:23:23
 Re: lost LVN demopart

A VCR! Wow! The more convoluted the more betterer! grin

Posted By

Lavina
on 2024-03-19
12:59:14
 Re: lost LVN demopart

ok, so an older Sony LCD TV found the plus4 signal with automatic analogue search easily from RF cable. New problem: none of my 3 1531's want to work, they don't move at all. :-/

Posted By

gerliczer
on 2024-03-19
13:48:18
 Re: lost LVN demopart

When you press the buttons (play, fast forward, rewind) on the 1531s do you hear the motor running? If you do you might have only a belt problem. That should be easy to fix. I saw somewhere replacement belts on the Internet but currently i don't have the faintest idea where that might have been. If you don't hear the characteristic noise then you might have a power problem. Either in the Datasette, in the Plussy or in the power brick. You should try all possible combinations of machines, Datasettes and power supplies.

Posted By

Lavina
on 2024-03-19
14:51:09
 Re: lost LVN demopart

it turned out that both PSUs I have lack the 9V. Darn.... :-/ Which is quite interesting, as the last time I checked they worked just fine. Can they just die in their sleep??

Posted By

gerliczer
on 2024-03-19
15:16:28
 Re: lost LVN demopart

That is some damn bad luck. I can't identify from the picture if your power supplies have square or round plugs. But if they are round and you have a C64 lying around you may try using the power brick of that.

Posted By

MMS
on 2024-03-19
18:30:18
 Re: lost LVN demopart

Yepp, maybe I am wrong but I see there an SD1541/II from Zoltan Kollár (RIP).

A very valuable and useful device. Loads GEOS perfectly (certainly only on C64)

Posted By

Lavina
on 2024-03-21
17:44:51
 Re: lost LVN demopart

Thanks to Verona, we managed to archive this lost part. Now you can find it on the GOTU Megademo page as downloadable.

I also found the GOTU Monitor (Or Gotumon) utility that was only listed in Moldi's 2nd. Catalogue I just don't remember the password for it and apparently noone does... So if you know anything about the exact author or the password, please come forward. Is there any known method to crack the Crazy Compresser password protection?? Thanks!

@MMS: Yes, I won it at Arok with Promised Land ;-)

Posted By

gerliczer
on 2024-03-21
16:50:02
 Re: lost LVN demopart and Gotu Monitor

Congratulations to your recovery of that relic. happy

I don't know if there are any methods to crack the password, but I remember that back in the days I somehow managed to figure out the password of Clues of Coders with analysing the decoder and some educated guesses about the protected content, as in it most probably starts with a BASIC startup line of SYS4###.

Posted By

Csabo
on 2024-03-21
17:12:05
 Re: lost LVN demopart and Gotu Monitor

Wow, what an awesome turn of events! Based on your initial description of the part, you remembered it really well happy

Posted By

Lavina
on 2024-03-21
17:18:37
 Re: lost LVN demopart and Gotu Monitor

Yeah I'm still missing the memory of the mentioned gotu logo with the circuit board design, it must be in some other release then. happy

Posted By

Csabo
on 2024-03-21
20:01:13
 Re: lost LVN demopart and Gotu Monitor

I managed to crack the password for GOTU Monitor: it's xenomena.

Posted By

gerliczer
on 2024-03-22
02:56:54
 Re: lost LVN demopart and Gotu Monitor

Could you describe your method, please.

Posted By

Lavina
on 2024-03-22
03:42:14
 Re: lost LVN demopart and Gotu Monitor

Darn, I was close. Last night we discussed with BSZ that it should be somehow cracked, and among the passwords I remembered and wrote to him (and I could not find on P4W) there was one: phenomena... But it did not work. grin

Release date is most probably 1991 or maybe 1990, but the author is still unknown.

Posted By

Csabo
on 2024-03-22
07:54:20
 Re: lost LVN demopart and Gotu Monitor

Sure! I disassembled the code and took a look at what it's doing. It's a simple RLE packer, EOR'ed with the password. By looking at the data, one can immediately see the cyclical nature of it - and assume that the password will be 4 characters long (since most of the data has a 4-byte repeating pattern).

The packer code starts depacking from $6F00 but also eventually jumps to $6F00. I think this was crucial for success, since it meant that the very first byte must be a valid opcode. (If it started depacking some data, any data, it would have been much harder, since it literally could be anything.) I took the first byte ($F1) and looked up what opcodes would result from that byte being EOR-ed with every lowercase and uppercase letter. Most of them didn't make any sense as a first instruction, but LDA #$xx ($A9) looked very promising, that gave me "x" as the starting letter. That LDA dictates that the 3rd byte will have to become an STA $xxxx ($8D), this gave me "n" as the 3rd letter.

Since I assumed it would be 4 letters, I tried some combinations, and "xena" was one of the guesses (name of the old TV show?). Try that and take a look at $6F00! The resulting code almost makes sense! I could literally see what it was trying to do: initialize some colors, clear the screen and jump to $7000. From there, I just kept "fixing" bytes to come up with letters. It's easy to see why "xenomena" produces a 4 byte repeating pattern.

It took me about an hour and a half. It was fun and very rewarding to see it start up happy



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